EyeLink Clinical and Oculomotor Eye-Tracking Publications
All EyeLink clinical and oculomotor research publications up until 2019 (with some early 2020s) are listed below by year. You can search the publications using keywords such as Saccadic Adaptation, Schizophrenia, Nystagmus, etc. You can also search for individual author names, and limit searches by year (choose the year then click the search button). If we missed any EyeLink clinical or oculomotor article, please email us!
All clinical and oculomotor publications are also available for download / import into reference management software as a single Bibtex (.bib) file.
2020 |
Anke Weidmann; Laura Richert; Maximilian Bernecker; Miriam Knauss; Kathlen Priebe; Benedikt Reuter; Martin Bohus; Meike Müller-Engelmann; Thomas Fydrich Dwelling on verbal but not pictorial threat cues: An eye-tracking study with adult survivors of childhood interpersonal violence Journal Article Psychological Trauma: Theory, Research, Practice, and Policy, 12 (1), pp. 46–54, 2020. @article{Weidmann2020, title = {Dwelling on verbal but not pictorial threat cues: An eye-tracking study with adult survivors of childhood interpersonal violence}, author = {Anke Weidmann and Laura Richert and Maximilian Bernecker and Miriam Knauss and Kathlen Priebe and Benedikt Reuter and Martin Bohus and Meike Müller-Engelmann and Thomas Fydrich}, doi = {10.1037/tra0000424}, year = {2020}, date = {2020-01-01}, journal = {Psychological Trauma: Theory, Research, Practice, and Policy}, volume = {12}, number = {1}, pages = {46--54}, abstract = {Objective: Previous studies have found evidence of an attentional bias for trauma-related stimuli in posttraumatic stress disorder (PTSD) using eye-tracking (ET) technlogy. However, it is unclear whether findings for PTSD after traumatic events in adulthood can be transferred to PTSD after interpersonal trauma in childhood. The latter is often accompanied by more complex symptom features, including, for example, affective dysregulation and has not yet been studied using ET. The aim of this study was to explore which components of attention are biased in adult victims of childhood trauma with PTSD compared to those without PTSD. Method: Female participants with (n = 27) or without (n = 27) PTSD who had experienced interpersonal violence in childhood or adolescence watched different traumarelated stimuli (Experiment 1: words, Experiment 2: facial expressions). We analyzed whether traumarelated stimuli were primarily detected (vigilance bias) and/or dwelled on longer (maintenance bias) compared to stimuli of other emotional qualities. Results: For trauma-related words, there was evidence of a maintenance bias but not of a vigilance bias. For trauma-related facial expressions, there was no evidence of any bias. Conclusions: At present, an attentional bias to trauma-related stimuli cannot be considered as robust in PTSD following trauma in childhood compared to that of PTSD following trauma in adulthood. The findings are discussed with respect to difficulties attributing effects specifically to PTSD in this highly comorbid though understudied population.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: Previous studies have found evidence of an attentional bias for trauma-related stimuli in posttraumatic stress disorder (PTSD) using eye-tracking (ET) technlogy. However, it is unclear whether findings for PTSD after traumatic events in adulthood can be transferred to PTSD after interpersonal trauma in childhood. The latter is often accompanied by more complex symptom features, including, for example, affective dysregulation and has not yet been studied using ET. The aim of this study was to explore which components of attention are biased in adult victims of childhood trauma with PTSD compared to those without PTSD. Method: Female participants with (n = 27) or without (n = 27) PTSD who had experienced interpersonal violence in childhood or adolescence watched different traumarelated stimuli (Experiment 1: words, Experiment 2: facial expressions). We analyzed whether traumarelated stimuli were primarily detected (vigilance bias) and/or dwelled on longer (maintenance bias) compared to stimuli of other emotional qualities. Results: For trauma-related words, there was evidence of a maintenance bias but not of a vigilance bias. For trauma-related facial expressions, there was no evidence of any bias. Conclusions: At present, an attentional bias to trauma-related stimuli cannot be considered as robust in PTSD following trauma in childhood compared to that of PTSD following trauma in adulthood. The findings are discussed with respect to difficulties attributing effects specifically to PTSD in this highly comorbid though understudied population. |
Judith Bek; Ellen Poliakoff; Karen Lander Measuring emotion recognition by people with Parkinson's disease using eye-tracking with dynamic facial expressions Journal Article Journal of Neuroscience Methods, 331 , pp. 1–7, 2020. @article{Bek2020, title = {Measuring emotion recognition by people with Parkinson's disease using eye-tracking with dynamic facial expressions}, author = {Judith Bek and Ellen Poliakoff and Karen Lander}, doi = {10.1016/j.jneumeth.2019.108524}, year = {2020}, date = {2020-01-01}, journal = {Journal of Neuroscience Methods}, volume = {331}, pages = {1--7}, abstract = {Background: Motion is an important cue to emotion recognition, and it has been suggested that we recognize emotions via internal simulation of others' expressions. There is a reduction of facial expression in Parkinson's disease (PD), which may influence the ability to use motion to recognise emotions in others. However, the majority of previous work in PD has used only static expressions. Moreover, few studies have used eye-tracking to explore emotion processing in PD. New method: We measured accuracy and eye movements in people with PD and healthy controls when identifying emotions from both static and dynamic facial expressions. Results: The groups did not differ overall in emotion recognition accuracy, but motion significantly increased recognition only in the control group. Participants made fewer and longer fixations when viewing dynamic expressions, and interest area analysis revealed increased gaze to the mouth region and decreased gaze to the eyes for dynamic stimuli, although the latter was specific to the control group. Comparison with existing methods: Ours is the first study to directly compare recognition of static and dynamic emotional expressions in PD using eye-tracking, revealing subtle differences between groups that may otherwise be undetected. Conclusions: It is feasible and informative to use eye-tracking with dynamic expressions to investigate emotion recognition in PD. Our findings suggest that people with PD may differ from healthy older adults in how they utilise motion during facial emotion recognition. Nonetheless, gaze patterns indicate some effects of motion on emotional processing, highlighting the need for further investigation in this area.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Motion is an important cue to emotion recognition, and it has been suggested that we recognize emotions via internal simulation of others' expressions. There is a reduction of facial expression in Parkinson's disease (PD), which may influence the ability to use motion to recognise emotions in others. However, the majority of previous work in PD has used only static expressions. Moreover, few studies have used eye-tracking to explore emotion processing in PD. New method: We measured accuracy and eye movements in people with PD and healthy controls when identifying emotions from both static and dynamic facial expressions. Results: The groups did not differ overall in emotion recognition accuracy, but motion significantly increased recognition only in the control group. Participants made fewer and longer fixations when viewing dynamic expressions, and interest area analysis revealed increased gaze to the mouth region and decreased gaze to the eyes for dynamic stimuli, although the latter was specific to the control group. Comparison with existing methods: Ours is the first study to directly compare recognition of static and dynamic emotional expressions in PD using eye-tracking, revealing subtle differences between groups that may otherwise be undetected. Conclusions: It is feasible and informative to use eye-tracking with dynamic expressions to investigate emotion recognition in PD. Our findings suggest that people with PD may differ from healthy older adults in how they utilise motion during facial emotion recognition. Nonetheless, gaze patterns indicate some effects of motion on emotional processing, highlighting the need for further investigation in this area. |
Raymond M Klein; Maryam Kavyani; Alireza Farsi; Michael A Lawrence Using the locus of slack logic to determine whether the output form of inhibition of return affects an early or late stage of processing Journal Article Cortex, 122 , pp. 123–130, 2020. @article{Klein2020, title = {Using the locus of slack logic to determine whether the output form of inhibition of return affects an early or late stage of processing}, author = {Raymond M Klein and Maryam Kavyani and Alireza Farsi and Michael A Lawrence}, doi = {10.1016/j.cortex.2018.10.023}, year = {2020}, date = {2020-01-01}, journal = {Cortex}, volume = {122}, pages = {123--130}, publisher = {Elsevier Ltd}, abstract = {Slower reaction times to targets presented at a previously cued or attended location are often attributed to inhibition of return (IOR). It has been suggested that IOR affects a process at the output end of processing continuum when it is generated while the oculomotor system is activated. Following the path set by Kavyani, Farsi, Abdoli, and Klein (2017) we used the locus of slack logic embedded in the psychological refractory period (PRP) paradigm to test this idea. We generated what we expected would be the output form of IOR by beginning each with participants making a target directed saccade which was followed by two tasks. Task 1, was a 2-choice auditory discrimination task and Task 2 was a 2-choice visual localization task. We varied the interval between the onsets of the two targets associated with these two tasks (using TTOAs of 200, 400, or 800 msec). As expected the visual task suffered from a robust PRP effect (substantially delayed RTs at the shorter TTOAs). There was also a robust IOR effect with RTs to localize visual targets being slower when the targets were presented at a previously fixated location. Importantly, and in striking to our previous results wherein we generated the input form of IOR, in the present study there was an additive effect between IOR and TTOA on RT2. As implied by the locus of slack logic, we therefore conclude that the form of IOR generated when the oculomotor system is activated affects a late stage of processing. Converging evidence for this conclusion, from a variety of neuroscientific methods, is presented and the dearth of such evidence about the input form of IOR is noted.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Slower reaction times to targets presented at a previously cued or attended location are often attributed to inhibition of return (IOR). It has been suggested that IOR affects a process at the output end of processing continuum when it is generated while the oculomotor system is activated. Following the path set by Kavyani, Farsi, Abdoli, and Klein (2017) we used the locus of slack logic embedded in the psychological refractory period (PRP) paradigm to test this idea. We generated what we expected would be the output form of IOR by beginning each with participants making a target directed saccade which was followed by two tasks. Task 1, was a 2-choice auditory discrimination task and Task 2 was a 2-choice visual localization task. We varied the interval between the onsets of the two targets associated with these two tasks (using TTOAs of 200, 400, or 800 msec). As expected the visual task suffered from a robust PRP effect (substantially delayed RTs at the shorter TTOAs). There was also a robust IOR effect with RTs to localize visual targets being slower when the targets were presented at a previously fixated location. Importantly, and in striking to our previous results wherein we generated the input form of IOR, in the present study there was an additive effect between IOR and TTOA on RT2. As implied by the locus of slack logic, we therefore conclude that the form of IOR generated when the oculomotor system is activated affects a late stage of processing. Converging evidence for this conclusion, from a variety of neuroscientific methods, is presented and the dearth of such evidence about the input form of IOR is noted. |
Li Zhang; Guoli Yan; Li Zhou; Zebo Lan; Valerie Benson Journal of Autism and Developmental Disorders, 50 , pp. 500–512, 2020. @article{Zhang2020, title = {The influence of irrelevant visual distractors on eye movement control in Chinese children with autism spectrum disorder: Evidence from the remote distractor paradigm}, author = {Li Zhang and Guoli Yan and Li Zhou and Zebo Lan and Valerie Benson}, doi = {10.1007/s10803-019-04271-y}, year = {2020}, date = {2020-01-01}, journal = {Journal of Autism and Developmental Disorders}, volume = {50}, pages = {500--512}, publisher = {Springer US}, abstract = {The current study examined eye movement control in autistic (ASD) children. Simple targets were presented in isolation, or with central, parafoveal, or peripheral distractors synchronously. Sixteen children with ASD (47–81 months) and nineteen age and IQ matched typically developing children were instructed to look to the target as accurately and quickly as possible. Both groups showed high proportions (40%) of saccadic errors towards parafoveal and peripheral distractors. For correctly executed eye movements to the targets, centrally presented distractors produced the longest latencies (time taken to initiate eye movements), followed by parafoveal and peripheral distractor conditions. Central distractors had a greater effect in the ASD group, indicating evidence for potential atypical voluntary attentional control in ASD children.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The current study examined eye movement control in autistic (ASD) children. Simple targets were presented in isolation, or with central, parafoveal, or peripheral distractors synchronously. Sixteen children with ASD (47–81 months) and nineteen age and IQ matched typically developing children were instructed to look to the target as accurately and quickly as possible. Both groups showed high proportions (40%) of saccadic errors towards parafoveal and peripheral distractors. For correctly executed eye movements to the targets, centrally presented distractors produced the longest latencies (time taken to initiate eye movements), followed by parafoveal and peripheral distractor conditions. Central distractors had a greater effect in the ASD group, indicating evidence for potential atypical voluntary attentional control in ASD children. |
Ziad M Hafed; Laurent Goffart Gaze direction as equilibrium: More evidence from spatial and temporal aspects of small-saccade triggering in the rhesus macaque monkey Journal Article Journal of Neurophysiology, 123 (1), pp. 308–322, 2020. @article{Hafed2020, title = {Gaze direction as equilibrium: More evidence from spatial and temporal aspects of small-saccade triggering in the rhesus macaque monkey}, author = {Ziad M Hafed and Laurent Goffart}, doi = {10.1152/jn.00588.2019}, year = {2020}, date = {2020-01-01}, journal = {Journal of Neurophysiology}, volume = {123}, number = {1}, pages = {308--322}, abstract = {Rigorous behavioral studies made in human subjects have shown that small-eccentricity target displacements are associated with increased saccadic reaction times, but the reasons for this remain unclear. Before characterizing the neurophysiological foundations underlying this relationship between the spatial and temporal aspects of saccades, we tested the triggering of small saccades in the male rhesus macaque monkey. We also compared our results to those obtained in human subjects, both from the existing literature and through our own additional measurements. Using a variety of behavioral tasks exercising visual and nonvisual guidance of small saccades, we found that small saccades consistently require more time than larger saccades to be triggered in the nonhuman primate, even in the absence of any visual guidance and when valid advance information about the saccade landing position is available. We also found a strong asymmetry in the reaction times of small upper versus lower visual field visually guided saccades, a phenomenon that has not been described before for small saccades, even in humans. Following the suggestion that an eye movement is not initiated as long as the visuo-oculomotor system is within a state of balance, in which opposing commands counterbalance each other, we propose that the longer reaction times are a signature of enhanced times needed to create the symmetry-breaking condition that puts downstream premotor neurons into a push-pull regime necessary for rotating the eyeballs. Our results provide an important catalog of nonhuman primate oculomotor capabilities on the miniature scale, allowing concrete predictions on underlying neurophysiological mechanisms.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rigorous behavioral studies made in human subjects have shown that small-eccentricity target displacements are associated with increased saccadic reaction times, but the reasons for this remain unclear. Before characterizing the neurophysiological foundations underlying this relationship between the spatial and temporal aspects of saccades, we tested the triggering of small saccades in the male rhesus macaque monkey. We also compared our results to those obtained in human subjects, both from the existing literature and through our own additional measurements. Using a variety of behavioral tasks exercising visual and nonvisual guidance of small saccades, we found that small saccades consistently require more time than larger saccades to be triggered in the nonhuman primate, even in the absence of any visual guidance and when valid advance information about the saccade landing position is available. We also found a strong asymmetry in the reaction times of small upper versus lower visual field visually guided saccades, a phenomenon that has not been described before for small saccades, even in humans. Following the suggestion that an eye movement is not initiated as long as the visuo-oculomotor system is within a state of balance, in which opposing commands counterbalance each other, we propose that the longer reaction times are a signature of enhanced times needed to create the symmetry-breaking condition that puts downstream premotor neurons into a push-pull regime necessary for rotating the eyeballs. Our results provide an important catalog of nonhuman primate oculomotor capabilities on the miniature scale, allowing concrete predictions on underlying neurophysiological mechanisms. |
William Rosengren; Marcus Nyström; Björn Hammar; Martin Stridh A robust method for calibration of eye tracking data recorded during nystagmus Journal Article Behavior Research Methods, 52 , pp. 36–50, 2020. @article{Rosengren2020, title = {A robust method for calibration of eye tracking data recorded during nystagmus}, author = {William Rosengren and Marcus Nyström and Björn Hammar and Martin Stridh}, doi = {10.3758/s13428-019-01199-0}, year = {2020}, date = {2020-01-01}, journal = {Behavior Research Methods}, volume = {52}, pages = {36--50}, abstract = {Eye tracking is a useful tool when studying the oscillatory eye movements associated with nystagmus. However, this oscillatory nature of nystagmus is problematic during calibration since it introduces uncertainty about where the person is actually looking. This renders comparisons between separate recordings unreliable. Still, the influence of the calibration protocol on eye movement data from people with nystagmus has not been thoroughly investigated. In this work, we propose a calibration method using Procrustes analysis in combination with an outlier correction algorithm, which is based on a model of the calibration data and on the geometry of the experimental setup. The proposed method is compared to previously used calibration polynomials in terms of accuracy, calibration plane distortion and waveform robustness. Six recordings of calibration data, validation data and optokinetic nystagmus data from people with nystagmus and seven recordings from a control group were included in the study. Fixation errors during the recording of calibration data from the healthy participants were introduced, simulating fixation errors caused by the oscillatory movements found in nystagmus data. The outlier correction algorithm improved the accuracy for all tested calibration methods. The accuracy and calibration plane distortion performance of the Procrustes analysis calibration method were similar to the top performing mapping functions for the simulated fixation errors. The performance in terms of waveform robustness was superior for the Procrustes analysis calibration compared to the other calibration methods. The overall performance of the Procrustes calibration methods was best for the datasets containing errors during the calibration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eye tracking is a useful tool when studying the oscillatory eye movements associated with nystagmus. However, this oscillatory nature of nystagmus is problematic during calibration since it introduces uncertainty about where the person is actually looking. This renders comparisons between separate recordings unreliable. Still, the influence of the calibration protocol on eye movement data from people with nystagmus has not been thoroughly investigated. In this work, we propose a calibration method using Procrustes analysis in combination with an outlier correction algorithm, which is based on a model of the calibration data and on the geometry of the experimental setup. The proposed method is compared to previously used calibration polynomials in terms of accuracy, calibration plane distortion and waveform robustness. Six recordings of calibration data, validation data and optokinetic nystagmus data from people with nystagmus and seven recordings from a control group were included in the study. Fixation errors during the recording of calibration data from the healthy participants were introduced, simulating fixation errors caused by the oscillatory movements found in nystagmus data. The outlier correction algorithm improved the accuracy for all tested calibration methods. The accuracy and calibration plane distortion performance of the Procrustes analysis calibration method were similar to the top performing mapping functions for the simulated fixation errors. The performance in terms of waveform robustness was superior for the Procrustes analysis calibration compared to the other calibration methods. The overall performance of the Procrustes calibration methods was best for the datasets containing errors during the calibration. |
Leanne Nagels; Roelien Bastiaanse; Deniz Başkent; Anita Wagnera Individual differences in lexical access among cochlear implant users Journal Article Journal of Speech, Language, and Hearing Research, 63 , pp. 286–304, 2020. @article{Nagels2020, title = {Individual differences in lexical access among cochlear implant users}, author = {Leanne Nagels and Roelien Bastiaanse and Deniz Başkent and Anita Wagnera}, year = {2020}, date = {2020-01-01}, journal = {Journal of Speech, Language, and Hearing Research}, volume = {63}, pages = {286--304}, abstract = {Purpose: The current study investigates how individual differences in cochlear implant (CI) users' sensitivity to word–nonword differences, reflecting lexical uncertainty, relate to their reliance on sentential context for lexical access in processing continuous speech. Method: Fifteen CI users and 14 normal-hearing (NH) controls participated in an auditory lexical decision task (Experiment 1) and a visual-world paradigm task (Experiment 2). Experiment 1 tested participants' reliance on lexical statistics, and Experiment 2 studied how sentential context affects the time course and patterns of lexical competition leading to lexical access. Results: In Experiment 1, CI users had lower accuracy scores and longer reaction times than NH listeners, particularly for nonwords. In Experiment 2, CI users' lexical competition patterns were, on average, similar to those of NH listeners, but the patterns of individual CI users varied greatly. Individual CI users' word–nonword sensitivity (Experiment 1) explained differences in the reliance on sentential context to resolve lexical competition, whereas clinical speech perception scores explained competition with phonologically related words. Conclusions: The general analysis of CI users' lexical competition patterns showed merely quantitative differences with NH listeners in the time course of lexical competition, but our additional analysis revealed more qualitative differences in CI users' strategies to process speech. Individuals' word–nonword sensitivity explained different parts of individual variability than clinical speech perception scores. These results stress, particularly for heterogeneous clinical populations such as CI users, the importance of investigating individual differences in addition to group averages, as they can be informative for clinical rehabilitation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Purpose: The current study investigates how individual differences in cochlear implant (CI) users' sensitivity to word–nonword differences, reflecting lexical uncertainty, relate to their reliance on sentential context for lexical access in processing continuous speech. Method: Fifteen CI users and 14 normal-hearing (NH) controls participated in an auditory lexical decision task (Experiment 1) and a visual-world paradigm task (Experiment 2). Experiment 1 tested participants' reliance on lexical statistics, and Experiment 2 studied how sentential context affects the time course and patterns of lexical competition leading to lexical access. Results: In Experiment 1, CI users had lower accuracy scores and longer reaction times than NH listeners, particularly for nonwords. In Experiment 2, CI users' lexical competition patterns were, on average, similar to those of NH listeners, but the patterns of individual CI users varied greatly. Individual CI users' word–nonword sensitivity (Experiment 1) explained differences in the reliance on sentential context to resolve lexical competition, whereas clinical speech perception scores explained competition with phonologically related words. Conclusions: The general analysis of CI users' lexical competition patterns showed merely quantitative differences with NH listeners in the time course of lexical competition, but our additional analysis revealed more qualitative differences in CI users' strategies to process speech. Individuals' word–nonword sensitivity explained different parts of individual variability than clinical speech perception scores. These results stress, particularly for heterogeneous clinical populations such as CI users, the importance of investigating individual differences in addition to group averages, as they can be informative for clinical rehabilitation. |
Kinan Muhammed; Edwin Dalmaijer; Sanjay Manohar; Masud Husain Voluntary modulation of saccadic peak velocity associated with individual differences in motivation Journal Article Cortex, 122 , pp. 198–212, 2020. @article{Muhammed2020, title = {Voluntary modulation of saccadic peak velocity associated with individual differences in motivation}, author = {Kinan Muhammed and Edwin Dalmaijer and Sanjay Manohar and Masud Husain}, doi = {10.1016/j.cortex.2018.12.001}, year = {2020}, date = {2020-01-01}, journal = {Cortex}, volume = {122}, pages = {198--212}, publisher = {Elsevier Ltd}, abstract = {Saccadic peak velocity increases in a stereotyped manner with the amplitude of eye movements. This relationship, known as the main sequence, has classically been considered to be fixed, although several recent studies have demonstrated that velocity can be modulated to some extent by external incentives. However, the ability to voluntarily control saccadic velocity and its association with motivation has yet to be investigated. Here, in three separate experimental paradigms, we measured the effects of incentivisation on saccadic velocity, reaction time and preparatory pupillary changes in 53 young healthy participants. In addition, the ability to voluntarily modulate saccadic velocity with and without incentivisation was assessed. Participants varied in their ability to increase and decrease the velocity of their saccades when instructed to do so. This effect correlated with motivation level across participants, and was further modulated by addition of monetary reward and avoidance of loss. The findings show that a degree of voluntary control of saccadic velocity is possible in some individuals, and that the ability to modulate peak velocity is associated with intrinsic levels of motivation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Saccadic peak velocity increases in a stereotyped manner with the amplitude of eye movements. This relationship, known as the main sequence, has classically been considered to be fixed, although several recent studies have demonstrated that velocity can be modulated to some extent by external incentives. However, the ability to voluntarily control saccadic velocity and its association with motivation has yet to be investigated. Here, in three separate experimental paradigms, we measured the effects of incentivisation on saccadic velocity, reaction time and preparatory pupillary changes in 53 young healthy participants. In addition, the ability to voluntarily modulate saccadic velocity with and without incentivisation was assessed. Participants varied in their ability to increase and decrease the velocity of their saccades when instructed to do so. This effect correlated with motivation level across participants, and was further modulated by addition of monetary reward and avoidance of loss. The findings show that a degree of voluntary control of saccadic velocity is possible in some individuals, and that the ability to modulate peak velocity is associated with intrinsic levels of motivation. |
A Pressigout; K Dore-Mazars How does number magnitude influence temporal and spatial parameters of eye movements? Journal Article Experimental Brain Research, 238 , pp. 101–109, 2020. @article{Pressigout2020, title = {How does number magnitude influence temporal and spatial parameters of eye movements?}, author = {A Pressigout and K Dore-Mazars}, doi = {10.1007/s00221-019-05701-0}, year = {2020}, date = {2020-01-01}, journal = {Experimental Brain Research}, volume = {238}, pages = {101--109}, publisher = {Springer Berlin Heidelberg}, abstract = {The influence of numerical processing on individuals' behavior is now well documented. The spatial representation of numbers on a left-to-right mental line (i.e., SNARC effect) has been shown to have sensorimotor consequences, the majority of studies being mainly concerned with its impact on the response times. Its impact on the motor programming stage remains less documented, although swiping movement amplitudes have recently been shown to be modulated by number magnitude. Regarding saccadic eye movements, the few available studies have not provided clear-cut conclusions. They showed that spatial–numerical associations modulated ocular drifts, but not the amplitude of memory-guided saccades. Because these studies held saccadic coordinates constant, which might have masked potential numerical effects, we examined whether spontaneous saccadic eye movements (with no saccadic target) could reflect numerical effects. Participants were asked to look either to the left or to the right side of an empty screen to estimate the magnitude (textless or textgreater 5) of a centrally presented digit. Latency data confirmed the presence of the classical SNARC and distance effects. More critically, saccade amplitude reflected a numerical effect: participants' saccades were longer for digits far from the standard (1 and 9) and were shorter for digits close to it (4 and 6). Our results suggest that beyond response times, kinematic parameters also offer valuable information for the understanding of the link between numerical cognition and motor programming.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The influence of numerical processing on individuals' behavior is now well documented. The spatial representation of numbers on a left-to-right mental line (i.e., SNARC effect) has been shown to have sensorimotor consequences, the majority of studies being mainly concerned with its impact on the response times. Its impact on the motor programming stage remains less documented, although swiping movement amplitudes have recently been shown to be modulated by number magnitude. Regarding saccadic eye movements, the few available studies have not provided clear-cut conclusions. They showed that spatial–numerical associations modulated ocular drifts, but not the amplitude of memory-guided saccades. Because these studies held saccadic coordinates constant, which might have masked potential numerical effects, we examined whether spontaneous saccadic eye movements (with no saccadic target) could reflect numerical effects. Participants were asked to look either to the left or to the right side of an empty screen to estimate the magnitude (textless or textgreater 5) of a centrally presented digit. Latency data confirmed the presence of the classical SNARC and distance effects. More critically, saccade amplitude reflected a numerical effect: participants' saccades were longer for digits far from the standard (1 and 9) and were shorter for digits close to it (4 and 6). Our results suggest that beyond response times, kinematic parameters also offer valuable information for the understanding of the link between numerical cognition and motor programming. |
Valerie M Beck; Timothy J Vickery Oculomotor capture reveals trial-by-trial neural correlates of attentional guidance by contents of visual working memory Journal Article Cortex, 122 , pp. 159–169, 2020. @article{Beck2020, title = {Oculomotor capture reveals trial-by-trial neural correlates of attentional guidance by contents of visual working memory}, author = {Valerie M Beck and Timothy J Vickery}, doi = {10.1016/j.cortex.2018.09.017}, year = {2020}, date = {2020-01-01}, journal = {Cortex}, volume = {122}, pages = {159--169}, publisher = {Elsevier Ltd}, abstract = {Evidence from attentional and oculomotor capture, contingent capture, and other paradigms suggests that mechanisms supporting human visual working memory (VWM) and visual attention are intertwined. Features held in VWM bias guidance toward matching items even when those features are task irrelevant. However, the neural basis of this interaction is underspecified. Prior examinations using fMRI have primarily relied on coarse comparisons across experimental conditions that produce varying amounts of capture. To examine the neural dynamics of attentional capture on a trial-by-trial basis, we applied an oculomotor paradigm that produced discrete measures of capture. On each trial, subjects were shown a memory item, followed by a blank retention interval, then a saccade target that appeared to the left or right. On some trials, an irrelevant distractor appeared above or below fixation. Once the saccade target was fixated, subjects completed a forced-choice memory test. Critically, either the target or distractor could match the feature held in VWM. Although task irrelevant, this manipulation produced differences in behavior: participants were more likely to saccade first to an irrelevant VWM-matching distractor compared with a non-matching distractor – providing a discrete measure of capture. We replicated this finding while recording eye movements and scanning participants' brains using fMRI. To examine the neural basis of oculomotor capture, we separately modeled the retention interval for capture and non-capture trials within the distractor-match condition. We found that frontal activity, including anterior cingulate cortex and superior frontal gyrus regions, differentially predicted subsequent oculomotor capture by a memory-matching distractor. Other regions previously implicated as involved in attentional capture by VWM-matching items showed no differential activity across capture and non-capture trials, even at a liberal threshold. Our findings demonstrate the power of trial-by-trial analyses of oculomotor capture as a means to examine the underlying relationship between VWM and attentional guidance systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Evidence from attentional and oculomotor capture, contingent capture, and other paradigms suggests that mechanisms supporting human visual working memory (VWM) and visual attention are intertwined. Features held in VWM bias guidance toward matching items even when those features are task irrelevant. However, the neural basis of this interaction is underspecified. Prior examinations using fMRI have primarily relied on coarse comparisons across experimental conditions that produce varying amounts of capture. To examine the neural dynamics of attentional capture on a trial-by-trial basis, we applied an oculomotor paradigm that produced discrete measures of capture. On each trial, subjects were shown a memory item, followed by a blank retention interval, then a saccade target that appeared to the left or right. On some trials, an irrelevant distractor appeared above or below fixation. Once the saccade target was fixated, subjects completed a forced-choice memory test. Critically, either the target or distractor could match the feature held in VWM. Although task irrelevant, this manipulation produced differences in behavior: participants were more likely to saccade first to an irrelevant VWM-matching distractor compared with a non-matching distractor – providing a discrete measure of capture. We replicated this finding while recording eye movements and scanning participants' brains using fMRI. To examine the neural basis of oculomotor capture, we separately modeled the retention interval for capture and non-capture trials within the distractor-match condition. We found that frontal activity, including anterior cingulate cortex and superior frontal gyrus regions, differentially predicted subsequent oculomotor capture by a memory-matching distractor. Other regions previously implicated as involved in attentional capture by VWM-matching items showed no differential activity across capture and non-capture trials, even at a liberal threshold. Our findings demonstrate the power of trial-by-trial analyses of oculomotor capture as a means to examine the underlying relationship between VWM and attentional guidance systems. |
Soazig Casteau; Daniel T Smith On the link between attentional search and the oculomotor system: Is preattentive search restricted to the range of eye movements? Journal Article Attention, Perception, & Psychophysics, pp. 1–15, 2020. @article{Casteau2020, title = {On the link between attentional search and the oculomotor system: Is preattentive search restricted to the range of eye movements?}, author = {Soazig Casteau and Daniel T Smith}, year = {2020}, date = {2020-01-01}, journal = {Attention, Perception, & Psychophysics}, pages = {1--15}, publisher = {Attention, Perception, & Psychophysics}, abstract = {It has been proposed that covert visual search can be fast, efficient, and stimulus driven, particularly when the target is defined by a salient single feature, or slow, inefficient, and effortful when the target is defined by a nonsalient conjunction offeatures. This distinction between fast, stimulus-driven orienting and slow, effortful orienting can be related to the distinction between exog- enous spatial attention and endogenous spatial attention. Several studies have shown that exogenous, covert orienting is limited to the range of saccadic eye movements, whereas covert endogenous orienting is independent of the range of saccadic eye movements. The current study examined whether covert visual search is affected in a similar way. Experiment 1 showed that covert visual search for feature singletons was impaired when stimuli were presented beyond the range of saccadic eye move- ments, whereas conjunction search was unaffected by array position. Experiment 2 replicated and extended this effect by measuring search times at 6 eccentricities. The impairment in covert feature search emerged only when stimuli crossed the effective oculomotor range and remained stable for locations further into the periphery, ruling out the possibility that the results of Experiment 1 were due to a failure to fully compensate for the effects of cortical magnification. The findings are interpreted in terms ofbiased competition and oculomotor theories ofspatial attention. It is concluded that, as with covert exogenous orienting, biological constraints on overt orienting in the oculomotor system constrain covert, preattentive search. Keywords}, keywords = {}, pubstate = {published}, tppubtype = {article} } It has been proposed that covert visual search can be fast, efficient, and stimulus driven, particularly when the target is defined by a salient single feature, or slow, inefficient, and effortful when the target is defined by a nonsalient conjunction offeatures. This distinction between fast, stimulus-driven orienting and slow, effortful orienting can be related to the distinction between exog- enous spatial attention and endogenous spatial attention. Several studies have shown that exogenous, covert orienting is limited to the range of saccadic eye movements, whereas covert endogenous orienting is independent of the range of saccadic eye movements. The current study examined whether covert visual search is affected in a similar way. Experiment 1 showed that covert visual search for feature singletons was impaired when stimuli were presented beyond the range of saccadic eye move- ments, whereas conjunction search was unaffected by array position. Experiment 2 replicated and extended this effect by measuring search times at 6 eccentricities. The impairment in covert feature search emerged only when stimuli crossed the effective oculomotor range and remained stable for locations further into the periphery, ruling out the possibility that the results of Experiment 1 were due to a failure to fully compensate for the effects of cortical magnification. The findings are interpreted in terms ofbiased competition and oculomotor theories ofspatial attention. It is concluded that, as with covert exogenous orienting, biological constraints on overt orienting in the oculomotor system constrain covert, preattentive search. Keywords |
2019 |
Isabel M Vanegas; Annabelle Blangero; James E Galvin; Alessandro Di Rocco; Angelo Quartarone; Felice M Ghilardi; Simon P Kelly Altered dynamics of visual contextual interactions in Parkinson's disease Journal Article npj Parkinson's Disease, 5 , pp. 1–8, 2019. @article{Vanegas2019, title = {Altered dynamics of visual contextual interactions in Parkinson's disease}, author = {Isabel M Vanegas and Annabelle Blangero and James E Galvin and Alessandro {Di Rocco} and Angelo Quartarone and Felice M Ghilardi and Simon P Kelly}, doi = {10.1038/s41531-019-0085-5}, year = {2019}, date = {2019-12-01}, journal = {npj Parkinson's Disease}, volume = {5}, pages = {1--8}, publisher = {Nature Publishing Group}, abstract = {Over the last decades, psychophysical and electrophysiological studies in patients and animal models of Parkinson's disease (PD), have consistently revealed a number of visual abnormalities. In particular, specific alterations of contrast sensitivity curves, electroretinogram (ERG), and visual-evoked potentials (VEP), have been attributed to dopaminergic retinal depletion. However, fundamental mechanisms of cortical visual processing, such as normalization or “gain control” computations, have not yet been examined in PD patients. Here, we measured electrophysiological indices of gain control in both space (surround suppression) and time (sensory adaptation) in PD patients based on steady-state VEP (ssVEP). Compared with controls, patients exhibited a significantly higher initial ssVEP amplitude that quickly decayed over time, and greater relative suppression of ssVEP amplitude as a function of surrounding stimulus contrast. Meanwhile, EEG frequency spectra were broadly elevated in patients relative to controls. Thus, contrary to what might be expected given the reduced contrast sensitivity often reported in PD, visual neural responses are not weaker; rather, they are initially larger but undergo an exaggerated degree of spatial and temporal gain control and are embedded within a greater background noise level. These differences may reflect cortical mechanisms that compensate for dysfunctional center-surround interactions at the retinal level.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Over the last decades, psychophysical and electrophysiological studies in patients and animal models of Parkinson's disease (PD), have consistently revealed a number of visual abnormalities. In particular, specific alterations of contrast sensitivity curves, electroretinogram (ERG), and visual-evoked potentials (VEP), have been attributed to dopaminergic retinal depletion. However, fundamental mechanisms of cortical visual processing, such as normalization or “gain control” computations, have not yet been examined in PD patients. Here, we measured electrophysiological indices of gain control in both space (surround suppression) and time (sensory adaptation) in PD patients based on steady-state VEP (ssVEP). Compared with controls, patients exhibited a significantly higher initial ssVEP amplitude that quickly decayed over time, and greater relative suppression of ssVEP amplitude as a function of surrounding stimulus contrast. Meanwhile, EEG frequency spectra were broadly elevated in patients relative to controls. Thus, contrary to what might be expected given the reduced contrast sensitivity often reported in PD, visual neural responses are not weaker; rather, they are initially larger but undergo an exaggerated degree of spatial and temporal gain control and are embedded within a greater background noise level. These differences may reflect cortical mechanisms that compensate for dysfunctional center-surround interactions at the retinal level. |
Felicity Deamer; Ellen Palmer; Quoc C Vuong; Nicol Ferrier; Andreas Finkelmeyer; Wolfram Hinzen; Stuart Watson Non-literal understanding and psychosis: Metaphor comprehension in individuals with a diagnosis of schizophrenia Journal Article Schizophrenia Research: Cognition, 18 , pp. 1–8, 2019. @article{Deamer2019, title = {Non-literal understanding and psychosis: Metaphor comprehension in individuals with a diagnosis of schizophrenia}, author = {Felicity Deamer and Ellen Palmer and Quoc C Vuong and Nicol Ferrier and Andreas Finkelmeyer and Wolfram Hinzen and Stuart Watson}, doi = {10.1016/J.SCOG.2019.100159}, year = {2019}, date = {2019-12-01}, journal = {Schizophrenia Research: Cognition}, volume = {18}, pages = {1--8}, publisher = {Elsevier}, abstract = {Previous studies suggest that understanding of non-literal expressions, and in particular metaphors, can be impaired in people with schizophrenia; although it is not clear why. We explored metaphor comprehension capacity using a novel picture selection paradigm; we compared task performance between people with schizophrenia and healthy comparator subjects and we further examined the relationships between the ability to interpret figurative expressions non-literally and performance on a number of other cognitive tasks. Eye-tracking was used to examine task strategy. We showed that even when IQ, years of education, and capacities for theory of mind and associative learning are factored in as covariates, patients are significantly more likely to interpret metaphorical expressions literally, despite eye-tracking findings suggesting that patients are following the same interpretation strategy as healthy controls. Inhibitory control deficits are likely to be one of multiple factors contributing to the poorer performance of our schizophrenia group on the metaphor trials of the picture selection task.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Previous studies suggest that understanding of non-literal expressions, and in particular metaphors, can be impaired in people with schizophrenia; although it is not clear why. We explored metaphor comprehension capacity using a novel picture selection paradigm; we compared task performance between people with schizophrenia and healthy comparator subjects and we further examined the relationships between the ability to interpret figurative expressions non-literally and performance on a number of other cognitive tasks. Eye-tracking was used to examine task strategy. We showed that even when IQ, years of education, and capacities for theory of mind and associative learning are factored in as covariates, patients are significantly more likely to interpret metaphorical expressions literally, despite eye-tracking findings suggesting that patients are following the same interpretation strategy as healthy controls. Inhibitory control deficits are likely to be one of multiple factors contributing to the poorer performance of our schizophrenia group on the metaphor trials of the picture selection task. |
Louise Kauffmann; Carole Peyrin; Alan Chauvin; Léa Entzmann; Camille Breuil; Nathalie Guyader Face perception influences the programming of eye movements Journal Article Scientific Reports, 9 , pp. 1–14, 2019. @article{Kauffmann2019, title = {Face perception influences the programming of eye movements}, author = {Louise Kauffmann and Carole Peyrin and Alan Chauvin and Léa Entzmann and Camille Breuil and Nathalie Guyader}, doi = {10.1038/s41598-018-36510-0}, year = {2019}, date = {2019-12-01}, journal = {Scientific Reports}, volume = {9}, pages = {1--14}, publisher = {Nature Publishing Group}, abstract = {Previous studies have shown that face stimuli elicit extremely fast and involuntary saccadic responses toward them, relative to other categories of visual stimuli. In the present study, we further investigated to what extent face stimuli influence the programming and execution of saccades examining their amplitude. We performed two experiments using a saccadic choice task: two images (one with a face, one with a vehicle) were simultaneously displayed in the left and right visual fields of participants who had to initiate a saccade toward the image (Experiment 1) or toward a cross in the image (Experiment 2) containing a target stimulus (a face or a vehicle). Results revealed shorter saccades toward vehicle than face targets, even if participants were explicitly asked to perform their saccades toward a specific location (Experiment 2). Furthermore, error saccades had smaller amplitude than correct saccades. Further analyses showed that error saccades were interrupted in mid-flight to initiate a concurrently-programmed corrective saccade. Overall, these data suggest that the content of visual stimuli can influence the programming of saccade amplitude, and that efficient online correction of saccades can be performed during the saccadic choice task.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Previous studies have shown that face stimuli elicit extremely fast and involuntary saccadic responses toward them, relative to other categories of visual stimuli. In the present study, we further investigated to what extent face stimuli influence the programming and execution of saccades examining their amplitude. We performed two experiments using a saccadic choice task: two images (one with a face, one with a vehicle) were simultaneously displayed in the left and right visual fields of participants who had to initiate a saccade toward the image (Experiment 1) or toward a cross in the image (Experiment 2) containing a target stimulus (a face or a vehicle). Results revealed shorter saccades toward vehicle than face targets, even if participants were explicitly asked to perform their saccades toward a specific location (Experiment 2). Furthermore, error saccades had smaller amplitude than correct saccades. Further analyses showed that error saccades were interrupted in mid-flight to initiate a concurrently-programmed corrective saccade. Overall, these data suggest that the content of visual stimuli can influence the programming of saccade amplitude, and that efficient online correction of saccades can be performed during the saccadic choice task. |
Mohsen Rakhshan; Vivian Lee; Emily Chu; Lauren Harris; Lillian Laiks; Peyman Khorsand; Alireza Soltani Influence of expected reward on temporal order judgment Journal Article Journal of Cognitive Neuroscience, pp. 1–17, 2019. @article{Rakhshan2019, title = {Influence of expected reward on temporal order judgment}, author = {Mohsen Rakhshan and Vivian Lee and Emily Chu and Lauren Harris and Lillian Laiks and Peyman Khorsand and Alireza Soltani}, doi = {10.1162/jocn_a_01516}, year = {2019}, date = {2019-12-01}, journal = {Journal of Cognitive Neuroscience}, pages = {1--17}, publisher = {MIT Press - Journals}, abstract = {Perceptual decision-making has been shown to be influenced by reward expected from alternative options or actions, but the underlying neural mechanisms are currently unknown. More specifically, it is debated whether reward effects are mediated through changes in sensory processing, later stages of decision-making, or both. To address this question, we conducted two experiments in which human participants made saccades to what they perceived to be either the first or second of two visually identical but asynchronously presented targets while we manipulated expected reward from correct and incorrect responses on each trial. By comparing reward-induced bias in target selection (i.e., reward bias) during the two experiments, we determined whether reward caused changes in sensory or decision-making processes. We found similar reward biases in the two experiments indicating that reward information mainly influenced later stages of decision-making [R1.1]. Moreover, the observed reward biases were independent of the individual's sensitivity to sensory signals. This suggests that reward effects were determined heuristically via modulation of decision-making processes instead of sensory processing. To further explain our findings and uncover plausible neural mechanisms, we simulated our experiments with a cortical network model and tested alternative mechanisms for how reward could exert its influence. We found that our experimental observations are more compatible with reward-dependent input to the output layer of the decision circuit. Together, our results suggest that, during a temporal judgment task, reward exerts its influence via changing later stages of decision-making (i.e., response bias) rather than early sensory processing (i.e., perceptual bias).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Perceptual decision-making has been shown to be influenced by reward expected from alternative options or actions, but the underlying neural mechanisms are currently unknown. More specifically, it is debated whether reward effects are mediated through changes in sensory processing, later stages of decision-making, or both. To address this question, we conducted two experiments in which human participants made saccades to what they perceived to be either the first or second of two visually identical but asynchronously presented targets while we manipulated expected reward from correct and incorrect responses on each trial. By comparing reward-induced bias in target selection (i.e., reward bias) during the two experiments, we determined whether reward caused changes in sensory or decision-making processes. We found similar reward biases in the two experiments indicating that reward information mainly influenced later stages of decision-making [R1.1]. Moreover, the observed reward biases were independent of the individual's sensitivity to sensory signals. This suggests that reward effects were determined heuristically via modulation of decision-making processes instead of sensory processing. To further explain our findings and uncover plausible neural mechanisms, we simulated our experiments with a cortical network model and tested alternative mechanisms for how reward could exert its influence. We found that our experimental observations are more compatible with reward-dependent input to the output layer of the decision circuit. Together, our results suggest that, during a temporal judgment task, reward exerts its influence via changing later stages of decision-making (i.e., response bias) rather than early sensory processing (i.e., perceptual bias). |
Michele Scaltritti; Aliaksei Miniukovich; Paola Venuti; Remo Job; Antonella De Angeli; Simone Sulpizio Investigating effects of typographic variables on webpage reading through eye movements Journal Article Scientific Reports, 9 , pp. 1–12, 2019. @article{Scaltritti2019, title = {Investigating effects of typographic variables on webpage reading through eye movements}, author = {Michele Scaltritti and Aliaksei Miniukovich and Paola Venuti and Remo Job and Antonella {De Angeli} and Simone Sulpizio}, doi = {10.1038/s41598-019-49051-x}, year = {2019}, date = {2019-12-01}, journal = {Scientific Reports}, volume = {9}, pages = {1--12}, publisher = {Nature Publishing Group}, abstract = {Webpage reading is ubiquitous in daily life. As Web technologies allow for a large variety of layouts and visual styles, the many formatting options may lead to poor design choices, including low readability. This research capitalizes on the existing readability guidelines for webpage design to outline several visuo-typographic variables and explore their effect on eye movements during webpage reading. Participants included children and adults, and for both groups typical readers and readers with dyslexia were considered. Actual webpages, rather than artificial ones, served as stimuli. This allowed to test multiple typographic variables in combination and in their typical ranges rather than in possibly unrealistic configurations. Several typographic variables displayed a significant effect on eye movements and reading performance. The effect was mostly homogeneous across the four groups, with a few exceptions. Beside supporting the notion that a few empirically-driven adjustments to the texts' visual appearance can facilitate reading across different populations, the results also highlight the challenge of making digital texts accessible to readers with dyslexia. Theoretically, the results highlight the importance of low-level visual factors, corroborating the emphasis of recent psychological models on visual attention and crowding in reading.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Webpage reading is ubiquitous in daily life. As Web technologies allow for a large variety of layouts and visual styles, the many formatting options may lead to poor design choices, including low readability. This research capitalizes on the existing readability guidelines for webpage design to outline several visuo-typographic variables and explore their effect on eye movements during webpage reading. Participants included children and adults, and for both groups typical readers and readers with dyslexia were considered. Actual webpages, rather than artificial ones, served as stimuli. This allowed to test multiple typographic variables in combination and in their typical ranges rather than in possibly unrealistic configurations. Several typographic variables displayed a significant effect on eye movements and reading performance. The effect was mostly homogeneous across the four groups, with a few exceptions. Beside supporting the notion that a few empirically-driven adjustments to the texts' visual appearance can facilitate reading across different populations, the results also highlight the challenge of making digital texts accessible to readers with dyslexia. Theoretically, the results highlight the importance of low-level visual factors, corroborating the emphasis of recent psychological models on visual attention and crowding in reading. |
Luke O'Gorman; Chelsea S Norman; Luke Michaels; Tutte Newall; Andrew H Crosby; Christopher Mattocks; Angela J Cree; Andrew J Lotery; Emma L Baple; Arjuna J Ratnayaka; Diana Baralle; Helena Lee; Daniel Osborne; Fatima Shawkat; Jane Gibson; Sarah Ennis; Jay E Self A small gene sequencing panel realises a high diagnostic rate in patients with congenital nystagmus following basic phenotyping Journal Article Scientific Reports, 9 , pp. 1–8, 2019. @article{OGorman2019, title = {A small gene sequencing panel realises a high diagnostic rate in patients with congenital nystagmus following basic phenotyping}, author = {Luke O'Gorman and Chelsea S Norman and Luke Michaels and Tutte Newall and Andrew H Crosby and Christopher Mattocks and Angela J Cree and Andrew J Lotery and Emma L Baple and Arjuna J Ratnayaka and Diana Baralle and Helena Lee and Daniel Osborne and Fatima Shawkat and Jane Gibson and Sarah Ennis and Jay E Self}, doi = {10.1038/s41598-019-49368-7}, year = {2019}, date = {2019-12-01}, journal = {Scientific Reports}, volume = {9}, pages = {1--8}, publisher = {Nature Publishing Group}, abstract = {Nystagmus is a disorder of uncontrolled eye movement and can occur as an isolated trait (idiopathic INS, IINS) or as part of multisystem disorders such as albinism, significant visual disorders or neurological disease. Eighty-one unrelated patients with nystagmus underwent routine ocular phenotyping using commonly available phenotyping methods and were grouped into four sub-cohorts according to the level of phenotyping information gained and their findings. DNA was extracted and sequenced using a broad utility next generation sequencing (NGS) gene panel. A clinical subpanel of genes for nystagmus/albinism was utilised and likely causal variants were prioritised according to methods currently employed by clinical diagnostic laboratories. We determine the likely underlying genetic cause for 43.2% of participants with similar yields regardless of prior phenotyping. This study demonstrates that a diagnostic workflow combining basic ocular phenotyping and a clinically available targeted NGS panel, can provide a high diagnostic yield for patients with infantile nystagmus, enabling access to disease specific management at a young age and reducing the need for multiple costly, often invasive tests. By describing diagnostic yield for groups of patients with incomplete phenotyping data, it also permits the subsequent design of ‘real-world' diagnostic workflows and illustrates the changing role of genetic testing in modern diagnostic workflows for heterogeneous ophthalmic disorders.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nystagmus is a disorder of uncontrolled eye movement and can occur as an isolated trait (idiopathic INS, IINS) or as part of multisystem disorders such as albinism, significant visual disorders or neurological disease. Eighty-one unrelated patients with nystagmus underwent routine ocular phenotyping using commonly available phenotyping methods and were grouped into four sub-cohorts according to the level of phenotyping information gained and their findings. DNA was extracted and sequenced using a broad utility next generation sequencing (NGS) gene panel. A clinical subpanel of genes for nystagmus/albinism was utilised and likely causal variants were prioritised according to methods currently employed by clinical diagnostic laboratories. We determine the likely underlying genetic cause for 43.2% of participants with similar yields regardless of prior phenotyping. This study demonstrates that a diagnostic workflow combining basic ocular phenotyping and a clinically available targeted NGS panel, can provide a high diagnostic yield for patients with infantile nystagmus, enabling access to disease specific management at a young age and reducing the need for multiple costly, often invasive tests. By describing diagnostic yield for groups of patients with incomplete phenotyping data, it also permits the subsequent design of ‘real-world' diagnostic workflows and illustrates the changing role of genetic testing in modern diagnostic workflows for heterogeneous ophthalmic disorders. |
Antonia F Ten Brink; Jasper H Fabius; Nick A Weaver; Tanja C W Nijboer; Stefan Van der Stigchel Trans-saccadic memory after right parietal brain damage Journal Article Cortex, 120 , pp. 284–297, 2019. @article{TenBrink2019a, title = {Trans-saccadic memory after right parietal brain damage}, author = {Antonia F {Ten Brink} and Jasper H Fabius and Nick A Weaver and Tanja C W Nijboer and Stefan {Van der Stigchel}}, doi = {10.1016/j.cortex.2019.06.006}, year = {2019}, date = {2019-11-01}, journal = {Cortex}, volume = {120}, pages = {284--297}, publisher = {Elsevier BV}, abstract = {INTRODUCTION: Spatial remapping, the process of updating information across eye movements, is an important mechanism for trans-saccadic perception. The right posterior parietal cortex (PPC) is a region that has been associated most strongly with spatial remapping. The aim of the project was to investigate the effect of damage to the right PPC on direction specific trans-saccadic memory. We compared trans-saccadic memory performance for central items that had to be remembered while making a left- versus rightward eye movement, or for items that were remapped within the left versus right visual field. METHODS: We included 9 stroke patients with unilateral right PPC lesions and 31 healthy control subjects. Participants memorized the location of a briefly presented item, had to make one saccade (either towards the left or right, or upward or downward), and subsequently had to decide in what direction the probe had shifted. We used a staircase to adjust task difficulty (i.e., the distance between the memory item and probe). Bayesian repeated measures ANOVAs were used to compare left versus right eye movements and items in the left versus right visual field. RESULTS: In both conditions, patients with right PPC damage showed worse trans-saccadic memory performance compared to healthy control subjects (for the condition with left- and rightward gaze shifts}, keywords = {}, pubstate = {published}, tppubtype = {article} } INTRODUCTION: Spatial remapping, the process of updating information across eye movements, is an important mechanism for trans-saccadic perception. The right posterior parietal cortex (PPC) is a region that has been associated most strongly with spatial remapping. The aim of the project was to investigate the effect of damage to the right PPC on direction specific trans-saccadic memory. We compared trans-saccadic memory performance for central items that had to be remembered while making a left- versus rightward eye movement, or for items that were remapped within the left versus right visual field. METHODS: We included 9 stroke patients with unilateral right PPC lesions and 31 healthy control subjects. Participants memorized the location of a briefly presented item, had to make one saccade (either towards the left or right, or upward or downward), and subsequently had to decide in what direction the probe had shifted. We used a staircase to adjust task difficulty (i.e., the distance between the memory item and probe). Bayesian repeated measures ANOVAs were used to compare left versus right eye movements and items in the left versus right visual field. RESULTS: In both conditions, patients with right PPC damage showed worse trans-saccadic memory performance compared to healthy control subjects (for the condition with left- and rightward gaze shifts |
Teresa Fasshauer; Andreas Sprenger; Karen Silling; Johanna Elisa Silberg; Anne Vosseler; Seiko Minoshita; Shinji Satoh; Michael Dorr; Katja Koelkebeck; Rebekka Lencer Visual exploration of emotional faces in schizophrenia using masks from the Japanese Noh theatre Journal Article Neuropsychologia, 133 , pp. 1–10, 2019. @article{Fasshauer2019, title = {Visual exploration of emotional faces in schizophrenia using masks from the Japanese Noh theatre}, author = {Teresa Fasshauer and Andreas Sprenger and Karen Silling and Johanna Elisa Silberg and Anne Vosseler and Seiko Minoshita and Shinji Satoh and Michael Dorr and Katja Koelkebeck and Rebekka Lencer}, doi = {10.1016/j.neuropsychologia.2019.107193}, year = {2019}, date = {2019-10-01}, journal = {Neuropsychologia}, volume = {133}, pages = {1--10}, abstract = {Studying eye movements during visual exploration is widely used to investigate visual information processing in schizophrenia. Here, we used masks from the Japanese Noh theatre to study visual exploration behavior during an emotional face recognition task and a brightness evaluation control task using the same stimuli. Eye movements were recorded in 25 patients with schizophrenia and 25 age-matched healthy controls while participants explored seven photos of Japanese Noh masks tilted to seven different angles. Additionally, parti- cipants were assessed on seven upright binary black and white pictures of these Noh masks (Mooney-like pictures), seven Upside-down pictures (180° upside-down turned Mooneys), and seven Neutral pictures. Participants either had to indicate whether they had recognized a face and its emotional expression, or they had to evaluate the brightness of the picture (total N=56 trials). We observed a clear effect of inclination angle of Noh masks on emotional ratings (ptextless0.001) and visual exploration behavior in both groups. Controls made larger saccades than patients when not being able to recognize a face in upside-down Mooney pictures (ptextless0.01). Patients also made smaller saccades when exploring pictures for brightness (ptextless0.05). Exploration behavior in patients was related to depressive symptom expression during emotional face recognition but not during brightness evaluation. Our findings suggest that visual exploration behavior in patients with schizophrenia is less flexible than in controls depending on the specific task requirements, specifically when exploring physical aspects of the environment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Studying eye movements during visual exploration is widely used to investigate visual information processing in schizophrenia. Here, we used masks from the Japanese Noh theatre to study visual exploration behavior during an emotional face recognition task and a brightness evaluation control task using the same stimuli. Eye movements were recorded in 25 patients with schizophrenia and 25 age-matched healthy controls while participants explored seven photos of Japanese Noh masks tilted to seven different angles. Additionally, parti- cipants were assessed on seven upright binary black and white pictures of these Noh masks (Mooney-like pictures), seven Upside-down pictures (180° upside-down turned Mooneys), and seven Neutral pictures. Participants either had to indicate whether they had recognized a face and its emotional expression, or they had to evaluate the brightness of the picture (total N=56 trials). We observed a clear effect of inclination angle of Noh masks on emotional ratings (ptextless0.001) and visual exploration behavior in both groups. Controls made larger saccades than patients when not being able to recognize a face in upside-down Mooney pictures (ptextless0.01). Patients also made smaller saccades when exploring pictures for brightness (ptextless0.05). Exploration behavior in patients was related to depressive symptom expression during emotional face recognition but not during brightness evaluation. Our findings suggest that visual exploration behavior in patients with schizophrenia is less flexible than in controls depending on the specific task requirements, specifically when exploring physical aspects of the environment. |
Bob McMurray; Jamie Klein-Packarda; Bruce J Tomblinb A real-time mechanism underlying lexical deficits in developmental language disorder: Between-word inhibition Journal Article Cognition, 191 , pp. 1–13, 2019. @article{McMurray2019a, title = {A real-time mechanism underlying lexical deficits in developmental language disorder: Between-word inhibition}, author = {Bob McMurray and Jamie Klein-Packarda and Bruce J Tomblinb}, doi = {10.1016/J.COGNITION.2019.06.012}, year = {2019}, date = {2019-10-01}, journal = {Cognition}, volume = {191}, pages = {1--13}, publisher = {Elsevier}, abstract = {Eight to 11% of children have a clinical disorder in oral language (Developmental Language Disorder, DLD). Language deficits in DLD can affect all levels of language and persist through adulthood. Word-level processing may be critical as words link phonology, orthography, syntax and semantics. Thus, a lexical deficit could cascade throughout language. Cognitively, word recognition is a competition process: as the input (e.g., lizard) unfolds, multiple candidates (liver, wizard) compete for recognition. Children with DLD do not fully resolve this competition, but it is unclear what cognitive mechanisms underlie this. We examined lexical inhibition—the ability of more active words to suppress competitors—in 79 adolescents with and without DLD. Participants heard words (e.g. net) in which the onset was manipulated to briefly favor a competitor (neck). This was predicted to inhibit the target, slowing recognition. Word recognition was measured using a task in which participants heard the stimulus, and clicked on a picture of the item from an array of competitors, while eye-movements were monitored as a measure of how strongly the participant was committed to that interpretation over time. TD listeners showed evidence of inhibition with greater interference for stimuli that briefly activated a competitor word. DLD listeners did not. This suggests deficits in DLD may stem from a failure to engage lexical inhibition. This in turn could have ripple effects throughout the language system. This supports theoretical approaches to DLD that emphasize lexical-level deficits, and deficits in real-time processing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eight to 11% of children have a clinical disorder in oral language (Developmental Language Disorder, DLD). Language deficits in DLD can affect all levels of language and persist through adulthood. Word-level processing may be critical as words link phonology, orthography, syntax and semantics. Thus, a lexical deficit could cascade throughout language. Cognitively, word recognition is a competition process: as the input (e.g., lizard) unfolds, multiple candidates (liver, wizard) compete for recognition. Children with DLD do not fully resolve this competition, but it is unclear what cognitive mechanisms underlie this. We examined lexical inhibition—the ability of more active words to suppress competitors—in 79 adolescents with and without DLD. Participants heard words (e.g. net) in which the onset was manipulated to briefly favor a competitor (neck). This was predicted to inhibit the target, slowing recognition. Word recognition was measured using a task in which participants heard the stimulus, and clicked on a picture of the item from an array of competitors, while eye-movements were monitored as a measure of how strongly the participant was committed to that interpretation over time. TD listeners showed evidence of inhibition with greater interference for stimuli that briefly activated a competitor word. DLD listeners did not. This suggests deficits in DLD may stem from a failure to engage lexical inhibition. This in turn could have ripple effects throughout the language system. This supports theoretical approaches to DLD that emphasize lexical-level deficits, and deficits in real-time processing. |
Christoph Huber-Huber; Antimo Buonocore; Olaf Dimigen; Clayton Hickey; David Melcher NeuroImage, 200 , pp. 344–362, 2019. @article{Huber-Huber2019, title = {The peripheral preview effect with faces: Combined EEG and eye-tracking suggests multiple stages of trans-saccadic predictive and non-predictive processing}, author = {Christoph Huber-Huber and Antimo Buonocore and Olaf Dimigen and Clayton Hickey and David Melcher}, doi = {10.1016/j.neuroimage.2019.06.059}, year = {2019}, date = {2019-10-01}, journal = {NeuroImage}, volume = {200}, pages = {344--362}, publisher = {Academic Press Inc.}, abstract = {The world appears stable despite saccadic eye-movements. One possible explanation for this phenomenon is that the visual system predicts upcoming input across saccadic eye-movements based on peripheral preview of the saccadic target. We tested this idea using concurrent electroencephalography (EEG) and eye-tracking. Participants made cued saccades to peripheral upright or inverted face stimuli that changed orientation (invalid preview) or maintained orientation (valid preview) while the saccade was completed. Experiment 1 demonstrated better discrimination performance and a reduced fixation-locked N170 component (fN170) with valid than with invalid preview, demonstrating integration of pre- and post-saccadic information. Moreover, the early fixation-related potentials (FRP) showed a preview face inversion effect suggesting that some pre-saccadic input was represented in the brain until around 170 ms post fixation-onset. Experiment 2 replicated Experiment 1 and manipulated the proportion of valid and invalid trials to test whether the preview effect reflects context-based prediction across trials. A whole-scalp Bayes factor analysis showed that this manipulation did not alter the fN170 preview effect but did influence the face inversion effect before the saccade. The pre-saccadic inversion effect declined earlier in the mostly invalid block than in the mostly valid block, which is consistent with the notion of pre-saccadic expectations. In addition, in both studies, we found strong evidence for an interaction between the pre-saccadic preview stimulus and the post-saccadic target as early as 50 ms (Experiment 2) or 90 ms (Experiment 1) into the new fixation. These findings suggest that visual stability may involve three temporal stages: prediction about the saccadic target, integration of pre-saccadic and post-saccadic information at around 50-90 ms post fixation onset, and post-saccadic facilitation of rapid categorization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The world appears stable despite saccadic eye-movements. One possible explanation for this phenomenon is that the visual system predicts upcoming input across saccadic eye-movements based on peripheral preview of the saccadic target. We tested this idea using concurrent electroencephalography (EEG) and eye-tracking. Participants made cued saccades to peripheral upright or inverted face stimuli that changed orientation (invalid preview) or maintained orientation (valid preview) while the saccade was completed. Experiment 1 demonstrated better discrimination performance and a reduced fixation-locked N170 component (fN170) with valid than with invalid preview, demonstrating integration of pre- and post-saccadic information. Moreover, the early fixation-related potentials (FRP) showed a preview face inversion effect suggesting that some pre-saccadic input was represented in the brain until around 170 ms post fixation-onset. Experiment 2 replicated Experiment 1 and manipulated the proportion of valid and invalid trials to test whether the preview effect reflects context-based prediction across trials. A whole-scalp Bayes factor analysis showed that this manipulation did not alter the fN170 preview effect but did influence the face inversion effect before the saccade. The pre-saccadic inversion effect declined earlier in the mostly invalid block than in the mostly valid block, which is consistent with the notion of pre-saccadic expectations. In addition, in both studies, we found strong evidence for an interaction between the pre-saccadic preview stimulus and the post-saccadic target as early as 50 ms (Experiment 2) or 90 ms (Experiment 1) into the new fixation. These findings suggest that visual stability may involve three temporal stages: prediction about the saccadic target, integration of pre-saccadic and post-saccadic information at around 50-90 ms post fixation onset, and post-saccadic facilitation of rapid categorization. |
Sabine Born Saccadic suppression of displacement does not reflect a saccade-specific bias to assume stability Journal Article Vision, 3 , pp. 1–22, 2019. @article{Born2019a, title = {Saccadic suppression of displacement does not reflect a saccade-specific bias to assume stability}, author = {Sabine Born}, doi = {10.3390/vision3040049}, year = {2019}, date = {2019-09-01}, journal = {Vision}, volume = {3}, pages = {1--22}, abstract = {Across saccades, small displacements of a visual target are harder to detect and their directions more difficult to discriminate than during steady fixation. Prominent theories of this effect, known as saccadic suppression of displacement, propose that it is due to a bias to assume object stability across saccades. Recent studies comparing the saccadic effect to masking effects suggest that suppression of displacement is not saccade-specific. Further evidence for this account is presented from two experiments where participants judged the size of displacements on a continuous scale in saccade and mask conditions, with and without blanking. Saccades and masks both reduced the proportion of correctly perceived displacements and increased the proportion of missed displacements. Blanking improved performance in both conditions by reducing the proportion of missed displacements. Thus, if suppression of displacement reflects a bias for stability, it is not a saccade-specific bias, but a more general stability assumption revealed under conditions of impoverished vision. Specifically, I discuss the potentially decisive role of motion or other transient signals for displacement perception. Without transients or motion, the quality of relative position signals is poor, and saccadic and mask-induced suppression of displacement reflects performance when the decision has to be made on these signals alone. Blanking may improve those position signals by providing a transient onset or a longer time to encode the pre-saccadic target position.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Across saccades, small displacements of a visual target are harder to detect and their directions more difficult to discriminate than during steady fixation. Prominent theories of this effect, known as saccadic suppression of displacement, propose that it is due to a bias to assume object stability across saccades. Recent studies comparing the saccadic effect to masking effects suggest that suppression of displacement is not saccade-specific. Further evidence for this account is presented from two experiments where participants judged the size of displacements on a continuous scale in saccade and mask conditions, with and without blanking. Saccades and masks both reduced the proportion of correctly perceived displacements and increased the proportion of missed displacements. Blanking improved performance in both conditions by reducing the proportion of missed displacements. Thus, if suppression of displacement reflects a bias for stability, it is not a saccade-specific bias, but a more general stability assumption revealed under conditions of impoverished vision. Specifically, I discuss the potentially decisive role of motion or other transient signals for displacement perception. Without transients or motion, the quality of relative position signals is poor, and saccadic and mask-induced suppression of displacement reflects performance when the decision has to be made on these signals alone. Blanking may improve those position signals by providing a transient onset or a longer time to encode the pre-saccadic target position. |
Jonathan van Leeuwen; Artem V Belopolsky Detection of object displacement during a saccade is prioritized by the oculomotor system Journal Article Journal of Vision, 19 (11), pp. 1–15, 2019. @article{Leeuwen2019, title = {Detection of object displacement during a saccade is prioritized by the oculomotor system}, author = {Jonathan van Leeuwen and Artem V Belopolsky}, doi = {10.1167/19.11.11}, year = {2019}, date = {2019-09-01}, journal = {Journal of Vision}, volume = {19}, number = {11}, pages = {1--15}, abstract = {The human eye-movement system is equipped with a sophisticated updating mechanism that can adjust for large retinal displacements produced by saccadic eye movements. The nature of this updating mechanism is still highly debated. Previous studies have demonstrated that updating can occur very rapidly and is initiated before the start of a saccade. In the present study, we used saccade curvature to demonstrate that the oculomotor system is tuned for detecting object displacements during saccades. Participants made a sequence of saccades while ignoring an irrelevant distractor. Curvature of the second saccade relative to the distractor was used to estimate the time course of updating. Saccade curvature away from the presaccadic location of the distractor emerged as early as 80 ms after the first saccade when the distractor was displaced during a saccade. This is about 50 ms earlier than when a distractor was only present before a saccade, only present after a saccade, or remained stationary across a saccade. This shows that the oculomotor system prioritizes detection of object displacements during saccades, which may be useful for guiding corrective saccades. The results also challenge previous views by demonstrating the additional role of postsaccadic information in updating target–distractor competition across saccades.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The human eye-movement system is equipped with a sophisticated updating mechanism that can adjust for large retinal displacements produced by saccadic eye movements. The nature of this updating mechanism is still highly debated. Previous studies have demonstrated that updating can occur very rapidly and is initiated before the start of a saccade. In the present study, we used saccade curvature to demonstrate that the oculomotor system is tuned for detecting object displacements during saccades. Participants made a sequence of saccades while ignoring an irrelevant distractor. Curvature of the second saccade relative to the distractor was used to estimate the time course of updating. Saccade curvature away from the presaccadic location of the distractor emerged as early as 80 ms after the first saccade when the distractor was displaced during a saccade. This is about 50 ms earlier than when a distractor was only present before a saccade, only present after a saccade, or remained stationary across a saccade. This shows that the oculomotor system prioritizes detection of object displacements during saccades, which may be useful for guiding corrective saccades. The results also challenge previous views by demonstrating the additional role of postsaccadic information in updating target–distractor competition across saccades. |
Sabrina E Twilhaar; Artem V Belopolsky; Jorrit F Kieviet; Ruurd M Elburg; Jaap Oosterlaan Voluntary and involuntary control of attention in adolescents born very preterm: A study of eye movements Journal Article Child Development, pp. 1–12, 2019. @article{Twilhaar2019, title = {Voluntary and involuntary control of attention in adolescents born very preterm: A study of eye movements}, author = {Sabrina E Twilhaar and Artem V Belopolsky and Jorrit F Kieviet and Ruurd M Elburg and Jaap Oosterlaan}, doi = {10.1111/cdev.13310}, year = {2019}, date = {2019-09-01}, journal = {Child Development}, pages = {1--12}, abstract = {Very preterm birth is associated with attention deficits that interfere with academic performance. A better understanding of attention processes is necessary to support very preterm born children. This study examined voluntary and involuntary attentional control in very preterm born adolescents by measuring saccadic eye movements. Additionally, these control processes were related to symptoms of inattention, intelligence, and academic performance. Participants included 47 very preterm and 61 full-term born 13-years-old adolescents. Oculomotor control was assessed using the antisaccade and oculomotor capture paradigm. Very preterm born adolescents showed deficits in antisaccade but not in oculomotor capture performance, indicating impairments in voluntary but not involuntary attentional control. These impairments mediated the relation between very preterm birth and inattention, intelligence, and academic performance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Very preterm birth is associated with attention deficits that interfere with academic performance. A better understanding of attention processes is necessary to support very preterm born children. This study examined voluntary and involuntary attentional control in very preterm born adolescents by measuring saccadic eye movements. Additionally, these control processes were related to symptoms of inattention, intelligence, and academic performance. Participants included 47 very preterm and 61 full-term born 13-years-old adolescents. Oculomotor control was assessed using the antisaccade and oculomotor capture paradigm. Very preterm born adolescents showed deficits in antisaccade but not in oculomotor capture performance, indicating impairments in voluntary but not involuntary attentional control. These impairments mediated the relation between very preterm birth and inattention, intelligence, and academic performance. |
Nils S Van Den Berg; Rients B Huitema; Jacoba M Spikman; Peter Jan Van Laar; Edward H F De Haan A shrunken world – micropsia after a right occipito-parietal ischemic stroke Journal Article Neurocase, 25 (5), pp. 202–208, 2019. @article{VanDenBerg2019, title = {A shrunken world – micropsia after a right occipito-parietal ischemic stroke}, author = {Nils S {Van Den Berg} and Rients B Huitema and Jacoba M Spikman and Peter Jan {Van Laar} and Edward H F {De Haan}}, doi = {10.1080/13554794.2019.1656751}, year = {2019}, date = {2019-09-01}, journal = {Neurocase}, volume = {25}, number = {5}, pages = {202--208}, publisher = {Informa UK Limited}, abstract = {Micropsia is a rare condition in which patients perceive the outside world smaller in size than it actually is. We examined a patient who, after a right occipito-parietal stroke, subjectively reported perceiving everything at seventy percent of the actual size. Using experimental tasks, we confirmed the extent of his micropsia at 70%. Visual half-field tests showed an impaired perception of shape, location and motion in the left visual field. As his micropsia concerns the complete visual field, we suggest that it is caused by a higher-order compensation process in order to reconcile the conflicting information from the two hemifields.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Micropsia is a rare condition in which patients perceive the outside world smaller in size than it actually is. We examined a patient who, after a right occipito-parietal stroke, subjectively reported perceiving everything at seventy percent of the actual size. Using experimental tasks, we confirmed the extent of his micropsia at 70%. Visual half-field tests showed an impaired perception of shape, location and motion in the left visual field. As his micropsia concerns the complete visual field, we suggest that it is caused by a higher-order compensation process in order to reconcile the conflicting information from the two hemifields. |
Lee Mcilreavy; Tom C A Freeman; Jonathan T Erichsen Two-dimensional analysis of smooth pursuit eye movements reveals quantitative deficits in precision and accuracy Journal Article Translational Vision Science & Technology, 8 (5), pp. 1–17, 2019. @article{Mcilreavy2019, title = {Two-dimensional analysis of smooth pursuit eye movements reveals quantitative deficits in precision and accuracy}, author = {Lee Mcilreavy and Tom C A Freeman and Jonathan T Erichsen}, doi = {10.1167/tvst.8.5.7}, year = {2019}, date = {2019-09-01}, journal = {Translational Vision Science & Technology}, volume = {8}, number = {5}, pages = {1--17}, publisher = {Association for Research in Vision and Ophthalmology (ARVO)}, abstract = {Purpose: Small moving targets are followed by pursuit eye movements, with success ubiquitously defined by gain. Gain quantifies accuracy, rather than precision, and only for eye movements along the target trajectory. Analogous to previous studies of fixation, we analyzed pursuit performance in two dimensions as a function of target direction, velocity, and amplitude. As a subsidiary experiment, we compared pursuit performance against that of fixation. Methods: Eye position was recorded from 15 observers during pursuit. The target was a 0.48 dot that moved across a large screen at 88/s or 168/s, either horizontally or vertically, through peak-to-peak amplitudes of 88,168,or 328. Two-dimensional eye velocity was expressed relative to the target, and a bivariate probability density function computed to obtain accuracy and precision. As a comparison, identical metrics were derived from fixation data. Results: For all target directions, eye velocity was less precise along the target trajectory. Eye velocities orthogonal to the target trajectory were more accurate during vertical pursuit than horizontal. Pursuit accuracy and precision along and orthogonal to the target trajectory decreased at the higher target velocity. Accuracy along the target trajectory decreased with smaller target amplitudes. Conclusions: Orthogonal to the target trajectory, pursuit was inaccurate and imprecise. Compared to fixation, pursuit was less precise and less accurate even when following the stimulus that gave the best performance. Translational Relevance: This analytical approach may help the detection of subtle deficits in slow phase eye movements that could be used as biomarkers for disease progression and/or treatment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Purpose: Small moving targets are followed by pursuit eye movements, with success ubiquitously defined by gain. Gain quantifies accuracy, rather than precision, and only for eye movements along the target trajectory. Analogous to previous studies of fixation, we analyzed pursuit performance in two dimensions as a function of target direction, velocity, and amplitude. As a subsidiary experiment, we compared pursuit performance against that of fixation. Methods: Eye position was recorded from 15 observers during pursuit. The target was a 0.48 dot that moved across a large screen at 88/s or 168/s, either horizontally or vertically, through peak-to-peak amplitudes of 88,168,or 328. Two-dimensional eye velocity was expressed relative to the target, and a bivariate probability density function computed to obtain accuracy and precision. As a comparison, identical metrics were derived from fixation data. Results: For all target directions, eye velocity was less precise along the target trajectory. Eye velocities orthogonal to the target trajectory were more accurate during vertical pursuit than horizontal. Pursuit accuracy and precision along and orthogonal to the target trajectory decreased at the higher target velocity. Accuracy along the target trajectory decreased with smaller target amplitudes. Conclusions: Orthogonal to the target trajectory, pursuit was inaccurate and imprecise. Compared to fixation, pursuit was less precise and less accurate even when following the stimulus that gave the best performance. Translational Relevance: This analytical approach may help the detection of subtle deficits in slow phase eye movements that could be used as biomarkers for disease progression and/or treatment. |
Eugene McSorley; Iain D Gilchrist; Rachel McCloy The role of fixation disengagement in the parallel programming of sequences of saccades Journal Article Experimental Brain Research, 237 (11), pp. 3033–3045, 2019. @article{McSorley2019, title = {The role of fixation disengagement in the parallel programming of sequences of saccades}, author = {Eugene McSorley and Iain D Gilchrist and Rachel McCloy}, doi = {10.1007/s00221-019-05641-9}, year = {2019}, date = {2019-09-01}, journal = {Experimental Brain Research}, volume = {237}, number = {11}, pages = {3033--3045}, abstract = {One of the core mechanisms involved in the control of saccade responses to selected target stimuli is the disengagement from the current fixation location, so that the next saccade can be executed. To carry out everyday visual tasks, we make multiple eye movements that can be programmed in parallel. However, the role of disengagement in the parallel programming of saccades has not been examined. It is well established that the need for disengagement slows down saccadic response time. This may be important in allowing the system to program accurate eye movements and have a role to play in the control of multiple eye movements but as yet this remains untested. Here, we report two experiments that seek to examine whether fixation disengagement reduces saccade latencies when the task completion demands multiple saccade responses. A saccade contingent paradigm was employed and participants were asked to execute saccadic eye movements to a series of seven targets while manipulating when these targets were shown. This both promotes fixation disengagement and controls the extent that parallel programming can occur. We found that trial duration decreased as more targets were made available prior to fixation: this was a result both of a reduction in the number of saccades being executed and in their saccade latencies. This supports the view that even when fixation disengagement is not required, parallel programming of multiple sequential saccadic eye movements is still present. By comparison with previous published data, we demonstrate a substantial speeded of response times in these condition (“a gap effect”) and that parallel programming is attenuated in these conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } One of the core mechanisms involved in the control of saccade responses to selected target stimuli is the disengagement from the current fixation location, so that the next saccade can be executed. To carry out everyday visual tasks, we make multiple eye movements that can be programmed in parallel. However, the role of disengagement in the parallel programming of saccades has not been examined. It is well established that the need for disengagement slows down saccadic response time. This may be important in allowing the system to program accurate eye movements and have a role to play in the control of multiple eye movements but as yet this remains untested. Here, we report two experiments that seek to examine whether fixation disengagement reduces saccade latencies when the task completion demands multiple saccade responses. A saccade contingent paradigm was employed and participants were asked to execute saccadic eye movements to a series of seven targets while manipulating when these targets were shown. This both promotes fixation disengagement and controls the extent that parallel programming can occur. We found that trial duration decreased as more targets were made available prior to fixation: this was a result both of a reduction in the number of saccades being executed and in their saccade latencies. This supports the view that even when fixation disengagement is not required, parallel programming of multiple sequential saccadic eye movements is still present. By comparison with previous published data, we demonstrate a substantial speeded of response times in these condition (“a gap effect”) and that parallel programming is attenuated in these conditions. |
Scott T Murdison; Gunnar Blohm; Frank Bremmer Saccade-induced changes in ocular torsion reveal predictive orientation perception Journal Article Journal of Vision, 19 (11), pp. 1–13, 2019. @article{Murdison2019, title = {Saccade-induced changes in ocular torsion reveal predictive orientation perception}, author = {Scott T Murdison and Gunnar Blohm and Frank Bremmer}, doi = {10.1167/19.11.10}, year = {2019}, date = {2019-09-01}, journal = {Journal of Vision}, volume = {19}, number = {11}, pages = {1--13}, abstract = {Natural orienting of gaze often results in a retinal image that is rotated relative to space due to ocular torsion. However, we perceive neither this rotation nor a moving world despite visual rotational motion on the retina. This perceptual stability is often attributed to the phenomenon known as predictive remapping, but the current remapping literature ignores this torsional component. In addition, studies often simply measure remapping across either space or features (e.g., orientation) but in natural circumstances, both components are bound together for stable perception. One natural circumstance in which the perceptual system must account for the current and future eye orientation to correctly interpret the orientation of external stimuli occurs during movements to or from oblique eye orientations (i.e., eye orientations with both a horizontal and vertical angular component relative to the primary position). Here we took advantage of oblique eye orientation-induced ocular torsion to examine perisaccadic orientation perception. First, we found that orientation perception was largely predicted by the rotated retinal image. Second, we observed a presaccadic remapping of orientation perception consistent with maintaining a stable (but spatially inaccurate) retinocentric perception throughout the saccade. These findings strongly suggest that our seamless perceptual stability relies on retinocentric signals that are predictively remapped in all three ocular dimensions with each saccade.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Natural orienting of gaze often results in a retinal image that is rotated relative to space due to ocular torsion. However, we perceive neither this rotation nor a moving world despite visual rotational motion on the retina. This perceptual stability is often attributed to the phenomenon known as predictive remapping, but the current remapping literature ignores this torsional component. In addition, studies often simply measure remapping across either space or features (e.g., orientation) but in natural circumstances, both components are bound together for stable perception. One natural circumstance in which the perceptual system must account for the current and future eye orientation to correctly interpret the orientation of external stimuli occurs during movements to or from oblique eye orientations (i.e., eye orientations with both a horizontal and vertical angular component relative to the primary position). Here we took advantage of oblique eye orientation-induced ocular torsion to examine perisaccadic orientation perception. First, we found that orientation perception was largely predicted by the rotated retinal image. Second, we observed a presaccadic remapping of orientation perception consistent with maintaining a stable (but spatially inaccurate) retinocentric perception throughout the saccade. These findings strongly suggest that our seamless perceptual stability relies on retinocentric signals that are predictively remapped in all three ocular dimensions with each saccade. |
Andrea Phillipou; Melissa Kirkovski; David J Castle; Caroline Gurvich; Larry A Abel; Stephanie Miles; Susan L Rossell High‐definition transcranial direct current stimulation in anorexia nervosa: A pilot study Journal Article International Journal of Eating Disorders, 52 (11), pp. 1274–1280, 2019. @article{Phillipou2019, title = {High‐definition transcranial direct current stimulation in anorexia nervosa: A pilot study}, author = {Andrea Phillipou and Melissa Kirkovski and David J Castle and Caroline Gurvich and Larry A Abel and Stephanie Miles and Susan L Rossell}, doi = {10.1002/eat.23146}, year = {2019}, date = {2019-08-01}, journal = {International Journal of Eating Disorders}, volume = {52}, number = {11}, pages = {1274--1280}, publisher = {Wiley}, abstract = {OBJECTIVE: Anorexia nervosa (AN) is a serious psychiatric condition often associated with poor outcomes. Biologically informed treatments for AN, such as brain stimulation, are lacking, in part due to the unclear nature of the neurobiological contributions to the illness. However, recent research has suggested a specific neurobiological target for the treatment of AN, namely stimulation of the inferior parietal lobe (IPL). The aim of this study was to stimulate-noninvasively-the left IPL in individuals with AN using high-definition transcranial direct current stimulation (HD-tDCS). METHOD: Twenty participants will be randomized to receive 10 daily sessions of HD-tDCS or sham HD-tDCS (placebo). Assessments will be carried out at baseline and end point, as well as 4- and 12-week follow-ups. DISCUSSION: This pilot investigation will primarily determine the feasibility and acceptability of this intervention.}, keywords = {}, pubstate = {published}, tppubtype = {article} } OBJECTIVE: Anorexia nervosa (AN) is a serious psychiatric condition often associated with poor outcomes. Biologically informed treatments for AN, such as brain stimulation, are lacking, in part due to the unclear nature of the neurobiological contributions to the illness. However, recent research has suggested a specific neurobiological target for the treatment of AN, namely stimulation of the inferior parietal lobe (IPL). The aim of this study was to stimulate-noninvasively-the left IPL in individuals with AN using high-definition transcranial direct current stimulation (HD-tDCS). METHOD: Twenty participants will be randomized to receive 10 daily sessions of HD-tDCS or sham HD-tDCS (placebo). Assessments will be carried out at baseline and end point, as well as 4- and 12-week follow-ups. DISCUSSION: This pilot investigation will primarily determine the feasibility and acceptability of this intervention. |
Ramina Adam; Kevin Johnston; Stefan Everling Journal of Neurophysiology, 122 (2), pp. 672–690, 2019. @article{Adam2019, title = {Recovery of contralesional saccade choice and reaction time deficits after a unilateral endothelin-1-induced lesion in the macaque caudal prefrontal cortex}, author = {Ramina Adam and Kevin Johnston and Stefan Everling}, doi = {10.1152/jn.00078.2019}, year = {2019}, date = {2019-08-01}, journal = {Journal of Neurophysiology}, volume = {122}, number = {2}, pages = {672--690}, publisher = {American Physiological Society Bethesda, MD}, abstract = {The caudal primate prefrontal cortex (PFC) is involved in target selection and visually guided saccades through both covert attention and overt orienting eye movements. Unilateral damage to the caudal PFC often leads to decreased awareness of a contralesional target alone, referred to as “neglect,” or when it is presented simultaneously with an ipsilesional target, referred to as “extinction.” In the current study, we examined whether deficits in contralesional target selection were due to contralesional oculomotor deficits, such as slower reaction times. We experimentally induced a focal ischemic lesion in the right caudal PFC of 4 male macaque monkeys using the vasoconstrictor endothelin-1 and measured saccade choice and reaction times on double-stimulus free-choice tasks and single-stimulus trials before and after the lesion. We found that 1) endothelin-1-induced lesions in the caudal PFC produced contralesional target selection deficits that varied in severity and duration based on lesion volume and location; 2) contralesional neglect-like deficits were transient and recovered by week 4 postlesion; 3) contralesional extinction-like deficits were longer lasting and recovered by weeks 8–16 postlesion; 4) contralesional reaction time returned to baseline well before the contralesional choice deficit had recovered; and 5) neither the mean reaction times nor the reaction time distributions could account for the degree of contralesional extinction on the free-choice task throughout recovery. These findings demonstrate that the saccade choice bias observed after a right caudal PFC lesion is not exclusively due to contralesional motor deficits, but instead reflects a combination of impaired motor and attentional processing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The caudal primate prefrontal cortex (PFC) is involved in target selection and visually guided saccades through both covert attention and overt orienting eye movements. Unilateral damage to the caudal PFC often leads to decreased awareness of a contralesional target alone, referred to as “neglect,” or when it is presented simultaneously with an ipsilesional target, referred to as “extinction.” In the current study, we examined whether deficits in contralesional target selection were due to contralesional oculomotor deficits, such as slower reaction times. We experimentally induced a focal ischemic lesion in the right caudal PFC of 4 male macaque monkeys using the vasoconstrictor endothelin-1 and measured saccade choice and reaction times on double-stimulus free-choice tasks and single-stimulus trials before and after the lesion. We found that 1) endothelin-1-induced lesions in the caudal PFC produced contralesional target selection deficits that varied in severity and duration based on lesion volume and location; 2) contralesional neglect-like deficits were transient and recovered by week 4 postlesion; 3) contralesional extinction-like deficits were longer lasting and recovered by weeks 8–16 postlesion; 4) contralesional reaction time returned to baseline well before the contralesional choice deficit had recovered; and 5) neither the mean reaction times nor the reaction time distributions could account for the degree of contralesional extinction on the free-choice task throughout recovery. These findings demonstrate that the saccade choice bias observed after a right caudal PFC lesion is not exclusively due to contralesional motor deficits, but instead reflects a combination of impaired motor and attentional processing. |
Jessica Klusek; Carly Moser; Joseph Schmidt; Leonard Abbeduto; Jane E Roberts A novel eye‐tracking paradigm for indexing social avoidance‐related behavior in fragile X syndrome Journal Article American Journal of Medical Genetics Part B: Neuropsychiatric Genetics, pp. 1–12, 2019. @article{Klusek2019, title = {A novel eye‐tracking paradigm for indexing social avoidance‐related behavior in fragile X syndrome}, author = {Jessica Klusek and Carly Moser and Joseph Schmidt and Leonard Abbeduto and Jane E Roberts}, doi = {10.1002/ajmg.b.32757}, year = {2019}, date = {2019-08-01}, journal = {American Journal of Medical Genetics Part B: Neuropsychiatric Genetics}, pages = {1--12}, publisher = {Wiley}, abstract = {Fragile X syndrome (FXS) is characterized by hallmark features of gaze avoidance, reduced social approach, and social anxiety. The development of therapeutics to manage these symptoms has been hindered, in part, by the lack of sensitive outcome measures. This study investigated the utility of a novel eye-tracking paradigm for indexing social avoidance-related phenotypes. Adolescent/young adult-aged males with FXS (n = 24) and typical development (n = 23) participated in the study. Participants viewed faces displaying direct or averted gaze and the first fixation duration on the eyes was recorded as an index of initial stimulus registration. Fixation durations did not differ across the direction of gaze conditions in either group, although the control group showed longer initial fixations on the eyes relative to the FXS group. Shorter initial fixation on averted gaze in males with FXS was a robust predictor of the severity of their social avoidance behavior exhibited during a social greeting context, whereas parent-reported social avoidance symptoms were not related to performance in the semi-naturalistic context. This eye-tracking paradigm may represent a promising outcome measure for FXS clinical trials because it provides a quantitative index that closely maps onto core social avoidance phenotypes of FXS, can be completed in less than 20 min, and is suitable for use with individuals with low IQ.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fragile X syndrome (FXS) is characterized by hallmark features of gaze avoidance, reduced social approach, and social anxiety. The development of therapeutics to manage these symptoms has been hindered, in part, by the lack of sensitive outcome measures. This study investigated the utility of a novel eye-tracking paradigm for indexing social avoidance-related phenotypes. Adolescent/young adult-aged males with FXS (n = 24) and typical development (n = 23) participated in the study. Participants viewed faces displaying direct or averted gaze and the first fixation duration on the eyes was recorded as an index of initial stimulus registration. Fixation durations did not differ across the direction of gaze conditions in either group, although the control group showed longer initial fixations on the eyes relative to the FXS group. Shorter initial fixation on averted gaze in males with FXS was a robust predictor of the severity of their social avoidance behavior exhibited during a social greeting context, whereas parent-reported social avoidance symptoms were not related to performance in the semi-naturalistic context. This eye-tracking paradigm may represent a promising outcome measure for FXS clinical trials because it provides a quantitative index that closely maps onto core social avoidance phenotypes of FXS, can be completed in less than 20 min, and is suitable for use with individuals with low IQ. |
Dong-Ho Lee; Sherryse L Corrow; Raika Pancaroglu; Jason J S Barton The scanpaths of subjects with developmental prosopagnosia during a face memory task Journal Article Brain Sciences, 9 , pp. 1–19, 2019. @article{Lee2019a, title = {The scanpaths of subjects with developmental prosopagnosia during a face memory task}, author = {Dong-Ho Lee and Sherryse L Corrow and Raika Pancaroglu and Jason J S Barton}, doi = {10.3390/brainsci9080188}, year = {2019}, date = {2019-08-01}, journal = {Brain Sciences}, volume = {9}, pages = {1--19}, publisher = {MDPI AG}, abstract = {The scanpaths of healthy subjects show biases towards the upper face, the eyes and the center of the face, which suggests that their fixations are guided by a feature hierarchy towards the regions most informative for face identification. However, subjects with developmental prosopagnosia have a lifelong impairment in face processing. Whether this is reflected in the loss of normal face-scanning strategies is not known. The goal of this study was to determine if subjects with developmental prosopagnosia showed anomalous scanning biases as they processed the identity of faces. We recorded the fixations of 10 subjects with developmental prosopagnosia as they performed a face memorization and recognition task, for comparison with 8 subjects with acquired prosopagnosia (four with anterior temporal lesions and four with occipitotemporal lesions) and 20 control subjects. The scanning of healthy subjects confirmed a bias to fixate the upper over the lower face, the eyes over the mouth, and the central over the peripheral face. Subjects with acquired prosopagnosia from occipitotemporal lesions had more dispersed fixations and a trend to fixate less informative facial regions. Subjects with developmental prosopagnosia did not differ from the controls. At a single-subject level, some developmental subjects performed abnormally, but none consistently across all metrics. Scanning distributions were not related to scores on perceptual or memory tests for faces. We conclude that despite lifelong difficulty with faces, subjects with developmental prosopagnosia still have an internal facial schema that guides their scanning behavior.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The scanpaths of healthy subjects show biases towards the upper face, the eyes and the center of the face, which suggests that their fixations are guided by a feature hierarchy towards the regions most informative for face identification. However, subjects with developmental prosopagnosia have a lifelong impairment in face processing. Whether this is reflected in the loss of normal face-scanning strategies is not known. The goal of this study was to determine if subjects with developmental prosopagnosia showed anomalous scanning biases as they processed the identity of faces. We recorded the fixations of 10 subjects with developmental prosopagnosia as they performed a face memorization and recognition task, for comparison with 8 subjects with acquired prosopagnosia (four with anterior temporal lesions and four with occipitotemporal lesions) and 20 control subjects. The scanning of healthy subjects confirmed a bias to fixate the upper over the lower face, the eyes over the mouth, and the central over the peripheral face. Subjects with acquired prosopagnosia from occipitotemporal lesions had more dispersed fixations and a trend to fixate less informative facial regions. Subjects with developmental prosopagnosia did not differ from the controls. At a single-subject level, some developmental subjects performed abnormally, but none consistently across all metrics. Scanning distributions were not related to scores on perceptual or memory tests for faces. We conclude that despite lifelong difficulty with faces, subjects with developmental prosopagnosia still have an internal facial schema that guides their scanning behavior. |
Matthew F Peterson; Ian Zaun; Harris Hoke; Guo Jiahui; Brad Duchaine; Nancy Kanwisher Eye movements and retinotopic tuning in developmental prosopagnosia Journal Article Journal of Vision, 19 (9), pp. 1–19, 2019. @article{Peterson2019, title = {Eye movements and retinotopic tuning in developmental prosopagnosia}, author = {Matthew F Peterson and Ian Zaun and Harris Hoke and Guo Jiahui and Brad Duchaine and Nancy Kanwisher}, doi = {10.1167/19.9.7}, year = {2019}, date = {2019-08-01}, journal = {Journal of Vision}, volume = {19}, number = {9}, pages = {1--19}, publisher = {The Association for Research in Vision and Ophthalmology}, abstract = {Despite extensive investigation, the causes and nature of developmental prosopagnosia (DP)—a severe face identification impairment in the absence of acquired brain injury—remain poorly understood. Drawing on previous work showing that individuals identified as being neurotypical (NT) show robust individual differences in where they fixate on faces, and recognize faces best when the faces are presented at this location, we defined and tested four novel hypotheses for how atypical face-looking behavior and/or retinotopic face encoding could impair face recognition in DP: (a) fixating regions of poor information, (b) inconsistent saccadic targeting, (c) weak retinotopic tuning, and (d) fixating locations not matched to the individual's own face tuning. We found no support for the first three hypotheses, with NTs and DPs consistently fixating similar locations and showing similar retinotopic tuning of their face perception performance. However, in testing the fourth hypothesis, we found preliminary evidence for two distinct phenotypes of DP: (a) Subjects characterized by impaired face memory, typical face perception, and a preference to look high on the face, and (b) Subjects characterized by profound impairments to both face memory and perception and a preference to look very low on the face. Further, while all NTs and upper-looking DPs performed best when faces were presented near their preferred fixation location, this was not true for lower-looking DPs. These results suggest that face recognition deficits in a substantial proportion of people with DP may arise not from aberrant face gaze or compromised retinotopic tuning, but from the suboptimal matching of gaze to tuning.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite extensive investigation, the causes and nature of developmental prosopagnosia (DP)—a severe face identification impairment in the absence of acquired brain injury—remain poorly understood. Drawing on previous work showing that individuals identified as being neurotypical (NT) show robust individual differences in where they fixate on faces, and recognize faces best when the faces are presented at this location, we defined and tested four novel hypotheses for how atypical face-looking behavior and/or retinotopic face encoding could impair face recognition in DP: (a) fixating regions of poor information, (b) inconsistent saccadic targeting, (c) weak retinotopic tuning, and (d) fixating locations not matched to the individual's own face tuning. We found no support for the first three hypotheses, with NTs and DPs consistently fixating similar locations and showing similar retinotopic tuning of their face perception performance. However, in testing the fourth hypothesis, we found preliminary evidence for two distinct phenotypes of DP: (a) Subjects characterized by impaired face memory, typical face perception, and a preference to look high on the face, and (b) Subjects characterized by profound impairments to both face memory and perception and a preference to look very low on the face. Further, while all NTs and upper-looking DPs performed best when faces were presented near their preferred fixation location, this was not true for lower-looking DPs. These results suggest that face recognition deficits in a substantial proportion of people with DP may arise not from aberrant face gaze or compromised retinotopic tuning, but from the suboptimal matching of gaze to tuning. |
Emma E M Stewart; Preeti Verghese; Anna Ma-Wyatt The spatial and temporal properties of attentional selectivity for saccades and reaches Journal Article Journal of Vision, 19 (9), pp. 1–19, 2019. @article{Stewart2019bb, title = {The spatial and temporal properties of attentional selectivity for saccades and reaches}, author = {Emma E M Stewart and Preeti Verghese and Anna Ma-Wyatt}, doi = {10.1167/19.9.12}, year = {2019}, date = {2019-08-01}, journal = {Journal of Vision}, volume = {19}, number = {9}, pages = {1--19}, publisher = {Association for Research in Vision and Ophthalmology (ARVO)}, abstract = {The preparation and execution of saccades and goal-directed movements elicits an accompanying shift in attention at the locus of the impending movement. However, some key aspects of the spatiotemporal profile of this attentional shift between eye and hand movements are not resolved. While there is evidence that attention is improved at the target location when making a reach, it is not clear how attention shifts over space and time around the movement target as a saccade and a reach are made to that target. Determining this spread of attention is an important aspect in understanding how attentional resources are used in relation to movement planning and guidance in real world tasks. We compared performance on a perceptual discrimination paradigm during a saccade- alone task, reach-alone task, and a saccade-plus-reach task to map the temporal profile of the premotor attentional shift at the goal of the movement and at three surrounding locations. We measured performance relative to a valid baseline level to determine whether motor planning induces additional attentional facilitation compared to mere covert attention. Sensitivity increased relative to movement onset at the target and at the surrounding locations, for both the saccade-alone and saccade-plus-reach conditions. The results suggest that the temporal profile of the attentional shift is similar for the two tasks involving saccades (saccade-alone and saccade-plus-reach tasks), but is very different when the influence of the saccade is removed. In this case, performance in the saccade-plus- reach task reflects the lower sensitivity observed when a reach-alone task is being conducted. In addition, the spatial profile of this spread of attention is not symmetrical around the target. This suggests that when a saccade and reach are being planned together, the saccade drives the attentional shift, and the reach-alone carries little attentional weight.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The preparation and execution of saccades and goal-directed movements elicits an accompanying shift in attention at the locus of the impending movement. However, some key aspects of the spatiotemporal profile of this attentional shift between eye and hand movements are not resolved. While there is evidence that attention is improved at the target location when making a reach, it is not clear how attention shifts over space and time around the movement target as a saccade and a reach are made to that target. Determining this spread of attention is an important aspect in understanding how attentional resources are used in relation to movement planning and guidance in real world tasks. We compared performance on a perceptual discrimination paradigm during a saccade- alone task, reach-alone task, and a saccade-plus-reach task to map the temporal profile of the premotor attentional shift at the goal of the movement and at three surrounding locations. We measured performance relative to a valid baseline level to determine whether motor planning induces additional attentional facilitation compared to mere covert attention. Sensitivity increased relative to movement onset at the target and at the surrounding locations, for both the saccade-alone and saccade-plus-reach conditions. The results suggest that the temporal profile of the attentional shift is similar for the two tasks involving saccades (saccade-alone and saccade-plus-reach tasks), but is very different when the influence of the saccade is removed. In this case, performance in the saccade-plus- reach task reflects the lower sensitivity observed when a reach-alone task is being conducted. In addition, the spatial profile of this spread of attention is not symmetrical around the target. This suggests that when a saccade and reach are being planned together, the saccade drives the attentional shift, and the reach-alone carries little attentional weight. |
Quan Wang; Carla A Wall; Erin C Barney; Jessica L Bradshaw; Suzanne L Macari; Katarzyna Chawarska; Frederick Shic Promoting social attention in 3‐year‐olds with ASD through gaze‐contingent eye tracking Journal Article Autism Research, 13 (1), pp. 61–73, 2019. @article{Wang2019h, title = {Promoting social attention in 3‐year‐olds with ASD through gaze‐contingent eye tracking}, author = {Quan Wang and Carla A Wall and Erin C Barney and Jessica L Bradshaw and Suzanne L Macari and Katarzyna Chawarska and Frederick Shic}, doi = {10.1002/aur.2199}, year = {2019}, date = {2019-08-01}, journal = {Autism Research}, volume = {13}, number = {1}, pages = {61--73}, publisher = {Wiley}, abstract = {Young children with autism spectrum disorder (ASD) look less toward faces compared to their non-ASD peers, limiting access to social learning. Currently, no technologies directly target these core social attention difficulties. This study examines the feasibility of automated gaze modification training for improving attention to faces in 3-year-olds with ASD. Using free-viewing data from typically developing (TD) controls (n = 41), we implemented gaze-contingent adaptive cueing to redirect children with ASD toward normative looking patterns during viewing of videos of an actress. Children with ASD were randomly assigned to either (a) an adaptive Cue condition (Cue}, keywords = {}, pubstate = {published}, tppubtype = {article} } Young children with autism spectrum disorder (ASD) look less toward faces compared to their non-ASD peers, limiting access to social learning. Currently, no technologies directly target these core social attention difficulties. This study examines the feasibility of automated gaze modification training for improving attention to faces in 3-year-olds with ASD. Using free-viewing data from typically developing (TD) controls (n = 41), we implemented gaze-contingent adaptive cueing to redirect children with ASD toward normative looking patterns during viewing of videos of an actress. Children with ASD were randomly assigned to either (a) an adaptive Cue condition (Cue |
Peng Zhou; Likan Zhan; Huimin Ma Understanding others' minds: Social inference in preschool children with autism spectrum disorder Journal Article Journal of Autism and Developmental Disorders, pp. 1–12, 2019. @article{Zhou2019a, title = {Understanding others' minds: Social inference in preschool children with autism spectrum disorder}, author = {Peng Zhou and Likan Zhan and Huimin Ma}, doi = {10.1007/s10803-019-04167-x}, year = {2019}, date = {2019-08-01}, journal = {Journal of Autism and Developmental Disorders}, pages = {1--12}, publisher = {Springer Science and Business Media LLC}, abstract = {The study used an eye-tracking task to investigate whether preschool children with autism spectrum disorder (ASD) are able to make inferences about others' behavior in terms of their mental states in a social setting. Fifty typically developing (TD) 4- and 5-year-olds and 22 5-year-olds with ASD participated in the study, where their eye-movements were recorded as automatic responses to given situations. The results show that unlike their TD peers, children with ASD failed to exhibit eye gaze patterns that reflect their ability to infer about others' behavior by spontaneously encoding socially relevant information and attributing mental states to others. Implications of the findings were discussed in relation to the proposal that implicit/spontaneous Theory of Mind is persistently impaired in ASD.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The study used an eye-tracking task to investigate whether preschool children with autism spectrum disorder (ASD) are able to make inferences about others' behavior in terms of their mental states in a social setting. Fifty typically developing (TD) 4- and 5-year-olds and 22 5-year-olds with ASD participated in the study, where their eye-movements were recorded as automatic responses to given situations. The results show that unlike their TD peers, children with ASD failed to exhibit eye gaze patterns that reflect their ability to infer about others' behavior by spontaneously encoding socially relevant information and attributing mental states to others. Implications of the findings were discussed in relation to the proposal that implicit/spontaneous Theory of Mind is persistently impaired in ASD. |
Alexander Goettker; Doris I Braun; Karl R Gegenfurtner Dynamic combination of position and motion information when tracking moving targets Journal Article Journal of Vision, 19 (7), pp. 1–22, 2019. @article{Goettker2019a, title = {Dynamic combination of position and motion information when tracking moving targets}, author = {Alexander Goettker and Doris I Braun and Karl R Gegenfurtner}, doi = {10.1167/19.7.2}, year = {2019}, date = {2019-07-01}, journal = {Journal of Vision}, volume = {19}, number = {7}, pages = {1--22}, publisher = {The Association for Research in Vision and Ophthalmology}, abstract = {To accurately foveate a moving target, the oculomotor system needs to estimate the position of the target at the saccade end, based on information about its position and ongoing movement, while accounting for neuronal delays and execution time of the saccade. We investigated human interceptive saccades and pursuit responses to moving targets defined by high and low luminance contrast or by chromatic contrast only (isoluminance). We used step-ramps with perpendicular directions between vertical target steps of 10 deg/s and horizontal ramps of 2.5 to 20 deg/s to separate errors with respect to the position step of the target in the vertical dimension, and errors related to target motion in the horizontal dimension. Interceptive saccades to targets of high and low luminance contrast landed close to the actual target positions, suggesting relatively accurate estimates of the amount of target displacement. Interceptive saccades to isoluminant targets were less accurate. They landed at positions the target had on average 100 ms before saccade onset. One account of this finding is that the integration of target motion is compromised for isoluminant targets moving in the periphery. In this case, the oculomotor system can use an accurate, but delayed position component, but cannot account for target movement. This deficit was also present for the postsaccadic pursuit speed. For the two luminance conditions, pursuit direction and speed were adjusted depending on the saccadic landing position. The rapid postsaccadic pursuit adjustments suggest shared position- and motion-related signals of target and eye for saccade and pursuit control.}, keywords = {}, pubstate = {published}, tppubtype = {article} } To accurately foveate a moving target, the oculomotor system needs to estimate the position of the target at the saccade end, based on information about its position and ongoing movement, while accounting for neuronal delays and execution time of the saccade. We investigated human interceptive saccades and pursuit responses to moving targets defined by high and low luminance contrast or by chromatic contrast only (isoluminance). We used step-ramps with perpendicular directions between vertical target steps of 10 deg/s and horizontal ramps of 2.5 to 20 deg/s to separate errors with respect to the position step of the target in the vertical dimension, and errors related to target motion in the horizontal dimension. Interceptive saccades to targets of high and low luminance contrast landed close to the actual target positions, suggesting relatively accurate estimates of the amount of target displacement. Interceptive saccades to isoluminant targets were less accurate. They landed at positions the target had on average 100 ms before saccade onset. One account of this finding is that the integration of target motion is compromised for isoluminant targets moving in the periphery. In this case, the oculomotor system can use an accurate, but delayed position component, but cannot account for target movement. This deficit was also present for the postsaccadic pursuit speed. For the two luminance conditions, pursuit direction and speed were adjusted depending on the saccadic landing position. The rapid postsaccadic pursuit adjustments suggest shared position- and motion-related signals of target and eye for saccade and pursuit control. |
Guillaume Doucet; Roberto A Gulli; Benjamin W Corrigan; Lyndon R Duong; Julio C Martinez‐Trujillo Modulation of local field potentials and neuronal activity in primate hippocampus during saccades Journal Article Hippocampus, pp. 1–18, 2019. @article{Doucet2019, title = {Modulation of local field potentials and neuronal activity in primate hippocampus during saccades}, author = {Guillaume Doucet and Roberto A Gulli and Benjamin W Corrigan and Lyndon R Duong and Julio C Martinez‐Trujillo}, doi = {10.1002/hipo.23140}, year = {2019}, date = {2019-07-01}, journal = {Hippocampus}, pages = {1--18}, publisher = {Wiley}, abstract = {Primates use saccades to gather information about objects and their relative spatial arrangement, a process essential for visual perception and memory. It has been proposed that signals linked to saccades reset the phase of local field potential (LFP) oscillations in the hippocampus, providing a temporal window for visual signals to activate neurons in this region and influence memory formation. We investigated this issue by measuring hippocampal LFPs and spikes in two macaques performing different tasks with unconstrained eye movements. We found that LFP phase clustering (PC) in the alpha/beta (8-16 Hz) frequencies followed foveation onsets, while PC in frequencies lower than 8 Hz followed spontaneous saccades, even on a homogeneous background. Saccades to a solid grey background were not followed by increases in local neuronal firing, whereas saccades toward appearing visual stimuli were. Finally, saccade parameters correlated with LFPs phase and amplitude: saccade direction correlated with delta (≤4 Hz) phase, and saccade amplitude with theta (4-8 Hz) power. Our results suggest that signals linked to saccades reach the hippocampus, producing synchronization of delta/theta LFPs without a general activation of local neurons. Moreover, some visual inputs co-occurring with saccades produce LFP synchronization in the alpha/beta bands and elevated neuronal firing. Our findings support the hypothesis that saccade-related signals enact sensory input-dependent plasticity and therefore memory formation in the primate hippocampus.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Primates use saccades to gather information about objects and their relative spatial arrangement, a process essential for visual perception and memory. It has been proposed that signals linked to saccades reset the phase of local field potential (LFP) oscillations in the hippocampus, providing a temporal window for visual signals to activate neurons in this region and influence memory formation. We investigated this issue by measuring hippocampal LFPs and spikes in two macaques performing different tasks with unconstrained eye movements. We found that LFP phase clustering (PC) in the alpha/beta (8-16 Hz) frequencies followed foveation onsets, while PC in frequencies lower than 8 Hz followed spontaneous saccades, even on a homogeneous background. Saccades to a solid grey background were not followed by increases in local neuronal firing, whereas saccades toward appearing visual stimuli were. Finally, saccade parameters correlated with LFPs phase and amplitude: saccade direction correlated with delta (≤4 Hz) phase, and saccade amplitude with theta (4-8 Hz) power. Our results suggest that signals linked to saccades reach the hippocampus, producing synchronization of delta/theta LFPs without a general activation of local neurons. Moreover, some visual inputs co-occurring with saccades produce LFP synchronization in the alpha/beta bands and elevated neuronal firing. Our findings support the hypothesis that saccade-related signals enact sensory input-dependent plasticity and therefore memory formation in the primate hippocampus. |
Mervyn G Thomas; Gail D E Maconachie; Cris S Constantinescu; Wai-Man Chan; Brenda Barry; Michael Hisaund; Viral Sheth; Helen J Kuht; Rob A Dineen; Sreemathi Harieaswar; Elizabeth C Engle; Irene Gottlob Congenital monocular elevation deficiency associated with a novel TUBB3 gene variant Journal Article British Journal of Ophthalmology, pp. 1–4, 2019. @article{Thomas2019, title = {Congenital monocular elevation deficiency associated with a novel TUBB3 gene variant}, author = {Mervyn G Thomas and Gail D E Maconachie and Cris S Constantinescu and Wai-Man Chan and Brenda Barry and Michael Hisaund and Viral Sheth and Helen J Kuht and Rob A Dineen and Sreemathi Harieaswar and Elizabeth C Engle and Irene Gottlob}, doi = {10.1136/bjophthalmol-2019-314293}, year = {2019}, date = {2019-07-01}, journal = {British Journal of Ophthalmology}, pages = {1--4}, publisher = {BMJ Publishing Group Ltd}, abstract = {BACKGROUND :The genetic basis of monocular elevation deficiency (MED) is unclear. It has previously been considered to arise due to a supranuclear abnormality. METHODS: Two brothers with MED were referred to Leicester Royal Infirmary, UK from the local opticians. Their father had bilateral ptosis and was unable to elevate both eyes, consistent with the diagnosis of congenital fibrosis of extraocular muscles (CFEOM). Candidate sequencing was performed in all family members. RESULTS: Both affected siblings (aged 7 and 12 years) were unable to elevate the right eye. Their father had bilateral ptosis, left esotropia and bilateral limitation of elevation. Chin up head posture was present in the older sibling and the father. Bell's phenomenon and vertical rotational vestibulo-ocular reflex were absent in the right eye for both children. Mild bilateral facial nerve palsy was present in the older sibling and the father. Both siblings had slight difficulty with tandem gait. MRI revealed hypoplastic oculomotor nerve. Left anterior insular focal cortical dysplasia was seen in the older sibling. Sequencing of TUBB3 revealed a novel heterozygous variant (c.1263GtextgreaterC, p.E421D) segregating with the phenotype. This residue is in the C-terminal H12 $alpha$-helix of $beta$-tubulin and is one of three putative kinesin binding sites. CONCLUSION: We show that familial MED can arise from a TUBB3 variant and could be considered a limited form of CFEOM. Neurological features such as mild facial palsy and cortical malformations can be present in patients with MED. Thus, in individuals with congenital MED, consideration may be made for TUBB3 mutation screening.}, keywords = {}, pubstate = {published}, tppubtype = {article} } BACKGROUND :The genetic basis of monocular elevation deficiency (MED) is unclear. It has previously been considered to arise due to a supranuclear abnormality. METHODS: Two brothers with MED were referred to Leicester Royal Infirmary, UK from the local opticians. Their father had bilateral ptosis and was unable to elevate both eyes, consistent with the diagnosis of congenital fibrosis of extraocular muscles (CFEOM). Candidate sequencing was performed in all family members. RESULTS: Both affected siblings (aged 7 and 12 years) were unable to elevate the right eye. Their father had bilateral ptosis, left esotropia and bilateral limitation of elevation. Chin up head posture was present in the older sibling and the father. Bell's phenomenon and vertical rotational vestibulo-ocular reflex were absent in the right eye for both children. Mild bilateral facial nerve palsy was present in the older sibling and the father. Both siblings had slight difficulty with tandem gait. MRI revealed hypoplastic oculomotor nerve. Left anterior insular focal cortical dysplasia was seen in the older sibling. Sequencing of TUBB3 revealed a novel heterozygous variant (c.1263GtextgreaterC, p.E421D) segregating with the phenotype. This residue is in the C-terminal H12 $alpha$-helix of $beta$-tubulin and is one of three putative kinesin binding sites. CONCLUSION: We show that familial MED can arise from a TUBB3 variant and could be considered a limited form of CFEOM. Neurological features such as mild facial palsy and cortical malformations can be present in patients with MED. Thus, in individuals with congenital MED, consideration may be made for TUBB3 mutation screening. |
Sanuji Gajamange; Annie Shelton; Meaghan Clough; Owen White; Joanne Fielding; Scott Kolbe Functional correlates of cognitive dysfunction in clinically isolated syndromes Journal Article PLOS ONE, 14 (7), pp. 1–13, 2019. @article{Gajamange2019, title = {Functional correlates of cognitive dysfunction in clinically isolated syndromes}, author = {Sanuji Gajamange and Annie Shelton and Meaghan Clough and Owen White and Joanne Fielding and Scott Kolbe}, editor = {Friedemann Paul}, doi = {10.1371/journal.pone.0219590}, year = {2019}, date = {2019-07-01}, journal = {PLOS ONE}, volume = {14}, number = {7}, pages = {1--13}, publisher = {Public Library of Science}, abstract = {Cognitive dysfunction can be identified in patients with clinically isolated syndromes suggestive of multiple sclerosis using ocular motor testing. This study aimed to identify the functional neural correlates of cognitive dysfunction in patients with clinically isolated syndrome using MRI. Eighteen patients with clinically isolated syndrome and 17 healthy controls were recruited. Subjects underwent standard neurological and neuropsychological testing. Subjects also underwent functional MRI (fMRI) during a cognitive ocular motor task, involving pro-saccade (direct gaze towards target) and anti-saccade (direct gaze away from target) trials. Ocular motor performance variables (averaged response time and error rate) were calculated for each subject. Patients showed a trend towards a greater rate of anti-saccade errors (p = 0.09) compared to controls. Compared to controls, patients exhibited increased activation in the right postcentral, right supramarginal gyrus, and the right parietal operculum during the anti-saccadetextgreaterpro-saccade contrast. This study demonstrated that changes in functional organisation of cognitive brain networks is associated with subtle cognitive changes in patients with clinically isolated syndrome.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cognitive dysfunction can be identified in patients with clinically isolated syndromes suggestive of multiple sclerosis using ocular motor testing. This study aimed to identify the functional neural correlates of cognitive dysfunction in patients with clinically isolated syndrome using MRI. Eighteen patients with clinically isolated syndrome and 17 healthy controls were recruited. Subjects underwent standard neurological and neuropsychological testing. Subjects also underwent functional MRI (fMRI) during a cognitive ocular motor task, involving pro-saccade (direct gaze towards target) and anti-saccade (direct gaze away from target) trials. Ocular motor performance variables (averaged response time and error rate) were calculated for each subject. Patients showed a trend towards a greater rate of anti-saccade errors (p = 0.09) compared to controls. Compared to controls, patients exhibited increased activation in the right postcentral, right supramarginal gyrus, and the right parietal operculum during the anti-saccadetextgreaterpro-saccade contrast. This study demonstrated that changes in functional organisation of cognitive brain networks is associated with subtle cognitive changes in patients with clinically isolated syndrome. |
Shira Klorfeld-Auslender; Nitzan Censor Visual-oculomotor interactions facilitate consolidation of perceptual learning Journal Article Journal of Vision, 19 (6), pp. 1–10, 2019. @article{Klorfeld-Auslender2019, title = {Visual-oculomotor interactions facilitate consolidation of perceptual learning}, author = {Shira Klorfeld-Auslender and Nitzan Censor}, doi = {10.1167/19.6.11}, year = {2019}, date = {2019-06-01}, journal = {Journal of Vision}, volume = {19}, number = {6}, pages = {1--10}, publisher = {The Association for Research in Vision and Ophthalmology}, abstract = {Visual skill learning is commonly considered a manifestation of brain plasticity. Following encoding, consolidation of the skill may result in between-session performance gains. A great volume of studies have demonstrated that during the offline consolidation interval, the skill is susceptible to external inputs that modify the preformed representation of the memory, affecting future performance. However, while basic visual perceptual learning is thought to be mediated by sensory brain regions or their higher-order readout pathways, the possibility of visual-oculomotor interactions affecting the consolidation interval and reshaping visual learning remains uncharted. Motivated by findings mapping connections between oculomotor behavior and visual performance, we examined whether visual consolidation can be facilitated by visual-oculomotor interactions. To this aim, we paired reactivation of an oculomotor memory with consolidation of a typical visual texture discrimination task. Importantly, the oculomotor memory was encoded by learning of the pure motor component of the movement, removing visual cues. When brief reactivation of the oculomotor memory preceded the visual task, visual gains were substantially enhanced compared with those achieved by visual practice per se and were strongly related to the magnitude of oculomotor gains, suggesting that the brain utilizes oculomotor memory to enhance basic visual perception.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Visual skill learning is commonly considered a manifestation of brain plasticity. Following encoding, consolidation of the skill may result in between-session performance gains. A great volume of studies have demonstrated that during the offline consolidation interval, the skill is susceptible to external inputs that modify the preformed representation of the memory, affecting future performance. However, while basic visual perceptual learning is thought to be mediated by sensory brain regions or their higher-order readout pathways, the possibility of visual-oculomotor interactions affecting the consolidation interval and reshaping visual learning remains uncharted. Motivated by findings mapping connections between oculomotor behavior and visual performance, we examined whether visual consolidation can be facilitated by visual-oculomotor interactions. To this aim, we paired reactivation of an oculomotor memory with consolidation of a typical visual texture discrimination task. Importantly, the oculomotor memory was encoded by learning of the pure motor component of the movement, removing visual cues. When brief reactivation of the oculomotor memory preceded the visual task, visual gains were substantially enhanced compared with those achieved by visual practice per se and were strongly related to the magnitude of oculomotor gains, suggesting that the brain utilizes oculomotor memory to enhance basic visual perception. |
Benjamin Tari; Mohammed A Fadel; Matthew Heath Response suppression produces a switch-cost for spatially compatible saccades Journal Article Experimental Brain Research, 237 (5), pp. 1195–1203, 2019. @article{Tari2019b, title = {Response suppression produces a switch-cost for spatially compatible saccades}, author = {Benjamin Tari and Mohammed A Fadel and Matthew Heath}, doi = {10.1007/s00221-019-05497-z}, year = {2019}, date = {2019-05-01}, journal = {Experimental Brain Research}, volume = {237}, number = {5}, pages = {1195--1203}, abstract = {Executive function supports the rapid alternation between tasks for online reconfiguration of attentional and motor goals. The oculomotor literature has found that a prosaccade (i.e., saccade to veridical target location) preceded by an antisaccade (i.e., saccade mirror symmetrical to a target) elicits an increase in reaction time (RT), whereas the converse switch does not. This switch-cost has been attributed to the antisaccade task's requirement of inhibiting a prosaccade (i.e., response suppression) and transforming a target's coordinate (i.e., vector inversion)—executive processes thought to contribute to a task-set inertia that proactively interferes with the planning of a subsequent prosaccade. It is, however, unclear whether response suppression and vector inversion contribute to a task-set inertia or whether the phenomenon relates to a unitary component (e.g., response suppression). Here, the same stimulus-driven (SD) prosaccades (i.e., respond at target onset) as used in previous work were used with minimally delayed (MD) prosaccades (i.e., respond at target offset) and arranged in an AABB paradigm (i.e.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Executive function supports the rapid alternation between tasks for online reconfiguration of attentional and motor goals. The oculomotor literature has found that a prosaccade (i.e., saccade to veridical target location) preceded by an antisaccade (i.e., saccade mirror symmetrical to a target) elicits an increase in reaction time (RT), whereas the converse switch does not. This switch-cost has been attributed to the antisaccade task's requirement of inhibiting a prosaccade (i.e., response suppression) and transforming a target's coordinate (i.e., vector inversion)—executive processes thought to contribute to a task-set inertia that proactively interferes with the planning of a subsequent prosaccade. It is, however, unclear whether response suppression and vector inversion contribute to a task-set inertia or whether the phenomenon relates to a unitary component (e.g., response suppression). Here, the same stimulus-driven (SD) prosaccades (i.e., respond at target onset) as used in previous work were used with minimally delayed (MD) prosaccades (i.e., respond at target offset) and arranged in an AABB paradigm (i.e. |
Shlomit Yuval-Greenberg; Anat Keren; Rinat Hilo; Adar Paz; Navah Ratzon Gaze control during simulator driving in adolescents with and without attention deficit hyperactivity disorder Journal Article American Journal of Occupational Therapy, 73 (3), pp. 1–8, 2019. @article{Yuval-Greenberg2019, title = {Gaze control during simulator driving in adolescents with and without attention deficit hyperactivity disorder}, author = {Shlomit Yuval-Greenberg and Anat Keren and Rinat Hilo and Adar Paz and Navah Ratzon}, doi = {10.5014/ajot.2019.031500}, year = {2019}, date = {2019-04-01}, journal = {American Journal of Occupational Therapy}, volume = {73}, number = {3}, pages = {1--8}, publisher = {American Occupational Therapy Association}, abstract = {Importance: Attention deficit hyperactivity disorder (ADHD) is associated with driving deficits. Visual standards for driving define minimum qualifications for safe driving, including acuity and field of vision, but they do not consider the ability to explore the environment efficiently by shifting the gaze, which is a critical element of safe driving. Objective: To examine visual exploration during simulated driving in adolescents with and without ADHD. Design: Adolescents with and without ADHD drove a driving simulator for approximately 10 min while their gaze was monitored. They then completed a battery of questionnaires. Setting: University lab. Participants: Participants with (n = 16) and without (n = 15) ADHD were included. Participants had a history of neurological disorders other than ADHD and normal or corrected-to-normal vision. Control participants reported not having a diagnosis of ADHD. Participants with ADHD had been previously diagnosed by a qualified professional. Outcomes and Measures: We compared the following measures between ADHD and non-ADHD groups: dashboard dwell times, fixation variance, entropy, and fixation duration. Results: Findings showed that participants with ADHD were more restricted in their patterns of exploration than control group participants. They spent considerably more time gazing at the dashboard and had longer periods of fixation with lower variability and randomness. Conclusions and Relevance: The results support the hypothesis that adolescents with ADHD engage in less active exploration during simulated driving. What This Article Adds: This study raises concerns regarding the driving competence of people with ADHD and opens up new directions for potential training programs that focus on exploratory gaze control.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Importance: Attention deficit hyperactivity disorder (ADHD) is associated with driving deficits. Visual standards for driving define minimum qualifications for safe driving, including acuity and field of vision, but they do not consider the ability to explore the environment efficiently by shifting the gaze, which is a critical element of safe driving. Objective: To examine visual exploration during simulated driving in adolescents with and without ADHD. Design: Adolescents with and without ADHD drove a driving simulator for approximately 10 min while their gaze was monitored. They then completed a battery of questionnaires. Setting: University lab. Participants: Participants with (n = 16) and without (n = 15) ADHD were included. Participants had a history of neurological disorders other than ADHD and normal or corrected-to-normal vision. Control participants reported not having a diagnosis of ADHD. Participants with ADHD had been previously diagnosed by a qualified professional. Outcomes and Measures: We compared the following measures between ADHD and non-ADHD groups: dashboard dwell times, fixation variance, entropy, and fixation duration. Results: Findings showed that participants with ADHD were more restricted in their patterns of exploration than control group participants. They spent considerably more time gazing at the dashboard and had longer periods of fixation with lower variability and randomness. Conclusions and Relevance: The results support the hypothesis that adolescents with ADHD engage in less active exploration during simulated driving. What This Article Adds: This study raises concerns regarding the driving competence of people with ADHD and opens up new directions for potential training programs that focus on exploratory gaze control. |
Sergio Delle Monache; Francesco Lacquaniti; Gianfranco Bosco Ocular tracking of occluded ballistic trajectories: Effects of visual context and of target law of motion Journal Article Journal of Vision, 19 (4), pp. 1–21, 2019. @article{Monache2019, title = {Ocular tracking of occluded ballistic trajectories: Effects of visual context and of target law of motion}, author = {Sergio Delle Monache and Francesco Lacquaniti and Gianfranco Bosco}, doi = {10.1167/19.4.13}, year = {2019}, date = {2019-04-01}, journal = {Journal of Vision}, volume = {19}, number = {4}, pages = {1--21}, publisher = {The Association for Research in Vision and Ophthalmology}, abstract = {In tracking a moving target, the visual context may provide cues for an observer to interpret the causal nature of the target motion and extract features to which the visual system is weakly sensitive, such as target acceleration. This information could be critical when vision of the target is temporarily impeded, requiring visual motion extrapolation processes. Here we investigated how visual context influences ocular tracking of motion either congruent or not with natural gravity. To this end, 28 subjects tracked computer-simulated ballistic trajectories either perturbed in the descending segment with altered gravity effects (0g/2g) or retaining natural-like motion (1g). Shortly after the perturbation (550 ms), targets disappeared for either 450 or 650 ms and became visible again until landing. Target motion occurred with either quasi-realistic pictorial cues or a uniform background, presented in counterbalanced order. We analyzed saccadic and pursuit movements after 0g and 2g target-motion perturbations and for corresponding intervals of unperturbed 1g trajectories, as well as after corresponding occlusions. Moreover, we considered the eye-to-target distance at target reappearance. Tracking parameters differed significantly between scenarios: With a neutral background, eye movements did not depend consistently on target motion, whereas with pictorial background they showed significant dependence, denoting better tracking of accelerated targets. These results suggest that oculomotor control is tuned to realistic properties of the visual scene.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In tracking a moving target, the visual context may provide cues for an observer to interpret the causal nature of the target motion and extract features to which the visual system is weakly sensitive, such as target acceleration. This information could be critical when vision of the target is temporarily impeded, requiring visual motion extrapolation processes. Here we investigated how visual context influences ocular tracking of motion either congruent or not with natural gravity. To this end, 28 subjects tracked computer-simulated ballistic trajectories either perturbed in the descending segment with altered gravity effects (0g/2g) or retaining natural-like motion (1g). Shortly after the perturbation (550 ms), targets disappeared for either 450 or 650 ms and became visible again until landing. Target motion occurred with either quasi-realistic pictorial cues or a uniform background, presented in counterbalanced order. We analyzed saccadic and pursuit movements after 0g and 2g target-motion perturbations and for corresponding intervals of unperturbed 1g trajectories, as well as after corresponding occlusions. Moreover, we considered the eye-to-target distance at target reappearance. Tracking parameters differed significantly between scenarios: With a neutral background, eye movements did not depend consistently on target motion, whereas with pictorial background they showed significant dependence, denoting better tracking of accelerated targets. These results suggest that oculomotor control is tuned to realistic properties of the visual scene. |
Lynn Huestegge; Oliver Herbort; Nora Gosch; Wilfried Kunde; Aleks Pieczykolan Free-choice saccades and their underlying determinants: Explorations of high-level voluntary oculomotor control Journal Article Journal of Vision, 19 (3), pp. 1–15, 2019. @article{Huestegge2019, title = {Free-choice saccades and their underlying determinants: Explorations of high-level voluntary oculomotor control}, author = {Lynn Huestegge and Oliver Herbort and Nora Gosch and Wilfried Kunde and Aleks Pieczykolan}, doi = {10.1167/19.3.14}, year = {2019}, date = {2019-03-01}, journal = {Journal of Vision}, volume = {19}, number = {3}, pages = {1--15}, publisher = {The Association for Research in Vision and Ophthalmology}, abstract = {Models of eye-movement control distinguish between different control levels, ranging from automatic (bottom-up, stimulus-driven selection) and automatized (based on well-learned routines) to voluntary (top-down, goal-driven selection, e.g., based on instructions). However, one type of voluntary control has yet only been examined in the manual and not in the oculomotor domain, namely free-choice selection among arbitrary targets, that is, targets that are of equal interest from both a bottom-up and topdown processing perspective. Here, we ask which features of targets (identity- or location-related) are used to determine such oculomotor free-choice behavior. In two experiments, participants executed a saccade to one of four peripheral targets in three different choice conditions: unconstrained free choice, constrained free choice based on target identity (color), and constrained free choice based on target location. The analysis of choice frequencies revealed that unconstrained free-choice selection closely resembled constrained choice based on target location. The results suggest that free-choice oculomotor control is mainly guided by spatial (location-based) target characteristics. We explain these results by assuming that participants tend to avoid less parsimonious recoding of target-identity representations into spatial codes, the latter being a necessary prerequisite to configure oculomotor commands.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Models of eye-movement control distinguish between different control levels, ranging from automatic (bottom-up, stimulus-driven selection) and automatized (based on well-learned routines) to voluntary (top-down, goal-driven selection, e.g., based on instructions). However, one type of voluntary control has yet only been examined in the manual and not in the oculomotor domain, namely free-choice selection among arbitrary targets, that is, targets that are of equal interest from both a bottom-up and topdown processing perspective. Here, we ask which features of targets (identity- or location-related) are used to determine such oculomotor free-choice behavior. In two experiments, participants executed a saccade to one of four peripheral targets in three different choice conditions: unconstrained free choice, constrained free choice based on target identity (color), and constrained free choice based on target location. The analysis of choice frequencies revealed that unconstrained free-choice selection closely resembled constrained choice based on target location. The results suggest that free-choice oculomotor control is mainly guided by spatial (location-based) target characteristics. We explain these results by assuming that participants tend to avoid less parsimonious recoding of target-identity representations into spatial codes, the latter being a necessary prerequisite to configure oculomotor commands. |
Matthew O Kimble; Andrew S Hyatt Vigilance/avoidance to expected and presented stimuli in trauma survivors: An eye-tracking study Journal Article Journal of Trauma & Dissociation, 20 (2), pp. 228–241, 2019. @article{Kimble2019, title = {Vigilance/avoidance to expected and presented stimuli in trauma survivors: An eye-tracking study}, author = {Matthew O Kimble and Andrew S Hyatt}, doi = {10.1080/15299732.2019.1572041}, year = {2019}, date = {2019-03-01}, journal = {Journal of Trauma & Dissociation}, volume = {20}, number = {2}, pages = {228--241}, publisher = {Routledge}, abstract = {Attention in trauma-related disorders has been characterized by both vigilance and avoidance of trauma-related or aversive stimuli. This study used eye-tracking technology to investigate how cumulative trauma, as well as hypervigilance and dissociative symptoms, affected attentional patterns to anticipated negative stimuli and actual negative stimuli. A sample of forty-two trauma participants recruited from the community had a choice about where to look on a computer screen knowing which segments of the screen negative stimuli were likely to appear. Participants could look at those stimuli for as long as they chose before pushing a button to move onto the next trial. A measure of hypervigilance predicted looking to quadrants in which a negative stimulus was to appear. Cumulative trauma predicted avoidance of those stimuli. Neither cumulative trauma or symptom profiles predicted how long participants looked at the negative pictures once they were presented. These data suggest that hypervigilance is associated with looking for threats that are not yet present, and that cumulative trauma may be associated with motivation to avoid negative stimuli. The findings are discussed with respect to the characteristics of the sample and the limited dissociative pathology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Attention in trauma-related disorders has been characterized by both vigilance and avoidance of trauma-related or aversive stimuli. This study used eye-tracking technology to investigate how cumulative trauma, as well as hypervigilance and dissociative symptoms, affected attentional patterns to anticipated negative stimuli and actual negative stimuli. A sample of forty-two trauma participants recruited from the community had a choice about where to look on a computer screen knowing which segments of the screen negative stimuli were likely to appear. Participants could look at those stimuli for as long as they chose before pushing a button to move onto the next trial. A measure of hypervigilance predicted looking to quadrants in which a negative stimulus was to appear. Cumulative trauma predicted avoidance of those stimuli. Neither cumulative trauma or symptom profiles predicted how long participants looked at the negative pictures once they were presented. These data suggest that hypervigilance is associated with looking for threats that are not yet present, and that cumulative trauma may be associated with motivation to avoid negative stimuli. The findings are discussed with respect to the characteristics of the sample and the limited dissociative pathology. |
Richard W Hertle; Ashraf Ahmad Clinical and electrophysiological results of eye muscle surgery in 17 patients with downbeat nystagmus Journal Article Indian Journal of Ophthalmology, 67 (1), pp. 109–115, 2019. @article{Hertle2019, title = {Clinical and electrophysiological results of eye muscle surgery in 17 patients with downbeat nystagmus}, author = {Richard W Hertle and Ashraf Ahmad}, doi = {10.4103/ijo.IJO}, year = {2019}, date = {2019-01-01}, journal = {Indian Journal of Ophthalmology}, volume = {67}, number = {1}, pages = {109--115}, abstract = {Purpose: To test the hypothesis that eye muscle surgery in treatment of patients with acquired downbeat nystagmus results in improvement measures of visual and ocular motor function. Methods: This is a prospective, interventional case series analysis of clinical and electrophyisological data before and after eye muscle surgery in 17 patients with acquired downbeat nystagmus who did not respond to medical treatments. Outcome measures included: 1) routine demography and clinical characteristics, 2) subjective oscillopsia (SO), 3) binocular best‑corrected visual acuity in the null position (BVA), 3) primary position strabismic deviation (SD), 5) anomalous head posture (AHP), 6) contrast sensitivity function (CS), and 7) nystagmus slow phase velocity (SPV). All patients were followed at least 12 months. Parametric and non‑parametric statistical analysis of outcome measure data above pre‑ and post‑treatment were perfomed using standard software on grouped data using computerized software. Results: Patients' age ranged from 5 to 85 years (average 27 years). About 59% were male. Follow up ranged from 1–10 years (average 2.0 years). Around 70% had an associated central nervous systemic diagnosis, 100% had an AHP, oscillopsia and decreased CS, 53% had other eye disease, and 59% had strabismus. There were no complications from surgery. There were signficant post‑treatment improvements in mean/median group BVA, SO, SD, AHP, CS, and SPV. Conclusion: This study supports the hypothesis that eye muscle surgery as treatments for patients with acquired downbeat nystagmus can result in improvements in multiple aspects of ocular motor and visual functions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Purpose: To test the hypothesis that eye muscle surgery in treatment of patients with acquired downbeat nystagmus results in improvement measures of visual and ocular motor function. Methods: This is a prospective, interventional case series analysis of clinical and electrophyisological data before and after eye muscle surgery in 17 patients with acquired downbeat nystagmus who did not respond to medical treatments. Outcome measures included: 1) routine demography and clinical characteristics, 2) subjective oscillopsia (SO), 3) binocular best‑corrected visual acuity in the null position (BVA), 3) primary position strabismic deviation (SD), 5) anomalous head posture (AHP), 6) contrast sensitivity function (CS), and 7) nystagmus slow phase velocity (SPV). All patients were followed at least 12 months. Parametric and non‑parametric statistical analysis of outcome measure data above pre‑ and post‑treatment were perfomed using standard software on grouped data using computerized software. Results: Patients' age ranged from 5 to 85 years (average 27 years). About 59% were male. Follow up ranged from 1–10 years (average 2.0 years). Around 70% had an associated central nervous systemic diagnosis, 100% had an AHP, oscillopsia and decreased CS, 53% had other eye disease, and 59% had strabismus. There were no complications from surgery. There were signficant post‑treatment improvements in mean/median group BVA, SO, SD, AHP, CS, and SPV. Conclusion: This study supports the hypothesis that eye muscle surgery as treatments for patients with acquired downbeat nystagmus can result in improvements in multiple aspects of ocular motor and visual functions. |
Alexandra Hoffmann; Ulrich Ettinger; Casandra Montoro; Gustavo A Reyes del Paso; Stefan Duschek Cerebral blood flow responses during prosaccade and antisaccade preparation in major depression Journal Article European Archives of Psychiatry and Clinical Neuroscience, 269 , pp. 813–822, 2019. @article{Hoffmann2019a, title = {Cerebral blood flow responses during prosaccade and antisaccade preparation in major depression}, author = {Alexandra Hoffmann and Ulrich Ettinger and Casandra Montoro and Gustavo A {Reyes del Paso} and Stefan Duschek}, doi = {10.1007/s00406-018-0956-5}, year = {2019}, date = {2019-01-01}, journal = {European Archives of Psychiatry and Clinical Neuroscience}, volume = {269}, pages = {813--822}, publisher = {Springer Berlin Heidelberg}, abstract = {While impairments in executive functions have been well established in major depressive disorder (MDD), specific deficits in proactive control have scarcely been studied so far. Proactive control refers to cognitive processes during anticipation of a behaviorally relevant event that facilitate readiness to react. In this study, cerebral blood flow responses were investigated in MDD patients during a precued antisaccade task requiring preparatory attention and proactive inhibition. Using functional transcranial Doppler sonography, blood flow velocities in the middle cerebral arteries of both hemispheres were recorded in 40 MDD patients and 40 healthy controls. In the task, a target appeared left or right of the fixation point 5 s after a cuing stimulus; subjects had to move their gaze to the target (prosaccade) or its mirror image position (antisaccade). Video-based eye-tracking was applied for ocular recording. A right dominant blood flow increase arose during prosaccade and antisaccade preparation, which was smaller in MDD patients than controls. Patients exhibited a higher error rate than controls for antisac- cades but not prosaccades. The smaller blood flow response may reflect blunted anticipatory activation of the dorsolateral prefrontal and inferior parietal cortices in MDD. The patients' increased antisaccade error rate suggests deficient inhibitory control. The findings support the notion of impairments in proactive control in MDD, which are clinically relevant as they may contribute to the deficits in cognition and behavioral regulation that characterize the disorder.}, keywords = {}, pubstate = {published}, tppubtype = {article} } While impairments in executive functions have been well established in major depressive disorder (MDD), specific deficits in proactive control have scarcely been studied so far. Proactive control refers to cognitive processes during anticipation of a behaviorally relevant event that facilitate readiness to react. In this study, cerebral blood flow responses were investigated in MDD patients during a precued antisaccade task requiring preparatory attention and proactive inhibition. Using functional transcranial Doppler sonography, blood flow velocities in the middle cerebral arteries of both hemispheres were recorded in 40 MDD patients and 40 healthy controls. In the task, a target appeared left or right of the fixation point 5 s after a cuing stimulus; subjects had to move their gaze to the target (prosaccade) or its mirror image position (antisaccade). Video-based eye-tracking was applied for ocular recording. A right dominant blood flow increase arose during prosaccade and antisaccade preparation, which was smaller in MDD patients than controls. Patients exhibited a higher error rate than controls for antisac- cades but not prosaccades. The smaller blood flow response may reflect blunted anticipatory activation of the dorsolateral prefrontal and inferior parietal cortices in MDD. The patients' increased antisaccade error rate suggests deficient inhibitory control. The findings support the notion of impairments in proactive control in MDD, which are clinically relevant as they may contribute to the deficits in cognition and behavioral regulation that characterize the disorder. |
Taylor Hornung; Wen Hsuan Chan; Ralph Axel Müller; Jeanne Townsend; Brandon Keehn Dopaminergic hypo-activity and reduced theta-band power in autism spectrum disorder: A resting-state EEG study Journal Article International Journal of Psychophysiology, 146 , pp. 101–106, 2019. @article{Hornung2019, title = {Dopaminergic hypo-activity and reduced theta-band power in autism spectrum disorder: A resting-state EEG study}, author = {Taylor Hornung and Wen Hsuan Chan and Ralph Axel Müller and Jeanne Townsend and Brandon Keehn}, doi = {10.1016/j.ijpsycho.2019.08.012}, year = {2019}, date = {2019-01-01}, journal = {International Journal of Psychophysiology}, volume = {146}, pages = {101--106}, publisher = {Elsevier}, abstract = {Background: Prior studies using a variety of methodologies have reported inconsistent dopamine (DA) findings in individuals with autism spectrum disorder (ASD), ranging from dopaminergic hypo- to hyper-activity. Theta-band power derived from scalp-recorded electroencephalography (EEG), which may be associated with dopamine levels in frontal cortex, has also been shown to be atypical in ASD. The present study examined spontaneous eye-blink rate (EBR), an indirect, non-invasive measure of central dopaminergic activity, and theta power in children with ASD to determine: 1) whether ASD may be associated with atypical DA levels, and 2) whether dopaminergic dysfunction may be associated with aberrant theta-band activation. Method: Participants included thirty-two children with ASD and thirty-two age-, IQ-, and sex-matched typically developing (TD) children. Electroencephalography and eye-tracking data were acquired while participants completed an eyes-open resting-state session. Blinks were counted and EBR was determined by dividing blink frequency by session duration and theta power (4–7.5 Hz) was extracted from midline leads. Results: Eye-blink rate and theta-band activity were significantly reduced in children with ASD as compared to their TD peers. For all participants, greater midline theta power was associated with increased EBR (related to higher DA levels). Conclusions: These results suggest that ASD may be associated with dopaminergic hypo-activity, and that this may contribute to atypical theta-band power. Lastly, EBR may be a useful tool to non-invasively index dopamine levels in ASD and could potentially have many clinical applications, including selecting treatment options and monitoring treatment response.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Prior studies using a variety of methodologies have reported inconsistent dopamine (DA) findings in individuals with autism spectrum disorder (ASD), ranging from dopaminergic hypo- to hyper-activity. Theta-band power derived from scalp-recorded electroencephalography (EEG), which may be associated with dopamine levels in frontal cortex, has also been shown to be atypical in ASD. The present study examined spontaneous eye-blink rate (EBR), an indirect, non-invasive measure of central dopaminergic activity, and theta power in children with ASD to determine: 1) whether ASD may be associated with atypical DA levels, and 2) whether dopaminergic dysfunction may be associated with aberrant theta-band activation. Method: Participants included thirty-two children with ASD and thirty-two age-, IQ-, and sex-matched typically developing (TD) children. Electroencephalography and eye-tracking data were acquired while participants completed an eyes-open resting-state session. Blinks were counted and EBR was determined by dividing blink frequency by session duration and theta power (4–7.5 Hz) was extracted from midline leads. Results: Eye-blink rate and theta-band activity were significantly reduced in children with ASD as compared to their TD peers. For all participants, greater midline theta power was associated with increased EBR (related to higher DA levels). Conclusions: These results suggest that ASD may be associated with dopaminergic hypo-activity, and that this may contribute to atypical theta-band power. Lastly, EBR may be a useful tool to non-invasively index dopamine levels in ASD and could potentially have many clinical applications, including selecting treatment options and monitoring treatment response. |
Tzu-Yu Hsu; Hsin-Chien Lee; Timothy Joseph Lane; Marcus Missal Temporal preparation, impulsivity and short-term memory in depression Journal Article Frontiers in Behavioral Neuroscience, 13 , pp. 1–12, 2019. @article{Hsu2019a, title = {Temporal preparation, impulsivity and short-term memory in depression}, author = {Tzu-Yu Hsu and Hsin-Chien Lee and Timothy Joseph Lane and Marcus Missal}, doi = {10.3389/fnbeh.2019.00258}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Behavioral Neuroscience}, volume = {13}, pages = {1--12}, abstract = {Patient suffering of major depressive disorder (MDD) often complain that subjective time seems to “drag” with respect to physical time. This may point toward a generalized dysfunction of temporal processing in MDD. In the present study, we investigated temporal preparation in MDD. “Temporal preparation” refers to an increased readiness to act before an expected event; consequently, reaction time should be reduced. MDD patients and age-matched controls were required to make a saccadic eye movement between a central and an eccentric visual target after a variable duration preparatory period. We found that MDD patients produced a larger number of premature saccades, saccades initiated prior to the appearance of the expected stimulus. These saccades were not temporally controlled; instead, they seemed to reflect reduced inhibitory control causing oculomotor impulsivity. In contrast, the latency of visually guided saccades was strongly influenced by temporal preparation in controls; significantly less so, in MDD patients. This observed reduced temporal preparation in MDD was associated with a faster decay of short-term temporal memory. Moreover, in patients producing a lot of premature responses, temporal preparation to early imperative stimuli was increased. In conclusion, reduced temporal preparation and short-term temporal memory in the oculomotor domain supports the hypothesis that temporal processing was altered in MDD patients. Moreover, oculomotor impulsivity interacted with temporal preparation. These observed deficits could reflect other underlying aspects of abnormal time experience in MDD.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Patient suffering of major depressive disorder (MDD) often complain that subjective time seems to “drag” with respect to physical time. This may point toward a generalized dysfunction of temporal processing in MDD. In the present study, we investigated temporal preparation in MDD. “Temporal preparation” refers to an increased readiness to act before an expected event; consequently, reaction time should be reduced. MDD patients and age-matched controls were required to make a saccadic eye movement between a central and an eccentric visual target after a variable duration preparatory period. We found that MDD patients produced a larger number of premature saccades, saccades initiated prior to the appearance of the expected stimulus. These saccades were not temporally controlled; instead, they seemed to reflect reduced inhibitory control causing oculomotor impulsivity. In contrast, the latency of visually guided saccades was strongly influenced by temporal preparation in controls; significantly less so, in MDD patients. This observed reduced temporal preparation in MDD was associated with a faster decay of short-term temporal memory. Moreover, in patients producing a lot of premature responses, temporal preparation to early imperative stimuli was increased. In conclusion, reduced temporal preparation and short-term temporal memory in the oculomotor domain supports the hypothesis that temporal processing was altered in MDD patients. Moreover, oculomotor impulsivity interacted with temporal preparation. These observed deficits could reflect other underlying aspects of abnormal time experience in MDD. |
Deborah Kaiser; Gitta A Jacob; Linda van Zutphen; Nicolette Siep; Andreas Sprenger; Brunna Tuschen-Caffier; Alena Senft; Arnoud Arntz; Gregor Domes Biased attention to facial expressions of ambiguous emotions in borderline personality disorder: An eye-tracking study Journal Article Journal of Personality Disorders, 33 , pp. 1–28, 2019. @article{Kaiser2019, title = {Biased attention to facial expressions of ambiguous emotions in borderline personality disorder: An eye-tracking study}, author = {Deborah Kaiser and Gitta A Jacob and Linda van Zutphen and Nicolette Siep and Andreas Sprenger and Brunna Tuschen-Caffier and Alena Senft and Arnoud Arntz and Gregor Domes}, doi = {10.1521/pedi_2019_33_363}, year = {2019}, date = {2019-01-01}, journal = {Journal of Personality Disorders}, volume = {33}, pages = {1--28}, publisher = {Guilford Publications Inc.}, abstract = {Preliminary evidence suggests that biased attention could be crucial in fostering the emotion recognition abnormalities in borderline personality disorder (BPD). We compared BPD patients to Cluster-C personality disorder (CC) patients and non-patients (NP) regarding emotion recognition in ambiguous faces and their visual attention allocation to the eyes. The role of comorbid posttraumatic stress disorder (PTSD) in BPD regarding emotion recognition and visual attention was explored. BPD patients fixated the eyes of angry/happy, sad/happy, and fearful/sad blends longer than non-patients. This visual attention pattern was mainly driven by BPD patients with PTSD. This subgroup also demonstrated longer fixations than CC patients and a trend towards longer fixations than BPD patients without PTSD for the angry/happy and fearful/sad blends. Emotion recognition was not altered in BPD. Biased visual attention towards the eyes of ambiguous facial expressions in BPD might be due to trauma-related attentional bias rather than to impairments in facial emotion recognition.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Preliminary evidence suggests that biased attention could be crucial in fostering the emotion recognition abnormalities in borderline personality disorder (BPD). We compared BPD patients to Cluster-C personality disorder (CC) patients and non-patients (NP) regarding emotion recognition in ambiguous faces and their visual attention allocation to the eyes. The role of comorbid posttraumatic stress disorder (PTSD) in BPD regarding emotion recognition and visual attention was explored. BPD patients fixated the eyes of angry/happy, sad/happy, and fearful/sad blends longer than non-patients. This visual attention pattern was mainly driven by BPD patients with PTSD. This subgroup also demonstrated longer fixations than CC patients and a trend towards longer fixations than BPD patients without PTSD for the angry/happy and fearful/sad blends. Emotion recognition was not altered in BPD. Biased visual attention towards the eyes of ambiguous facial expressions in BPD might be due to trauma-related attentional bias rather than to impairments in facial emotion recognition. |
Minah Kim; Tak Hyung Lee; Jung-Seok Seok Choi; Yoo Bin Kwak; Wu Jeong Hwang; Taekwan Kim; Ji Yoon Lee; Bo Mi Kim; Jun Soo Kwon; Yoo Bin Kwak; Wu Jeong Hwang; Taekwan Kim; Ji Yoon Lee; Bo Mi Kim; Jun Soo Kwon Dysfunctional attentional bias and inhibitory control during anti-saccade task in patients with internet gaming disorder: An eye tracking study Journal Article Progress in Neuropsychopharmacology and Biological Psychiatry, 95 , pp. 1–7, 2019. @article{Kim2019b, title = {Dysfunctional attentional bias and inhibitory control during anti-saccade task in patients with internet gaming disorder: An eye tracking study}, author = {Minah Kim and Tak Hyung Lee and Jung-Seok Seok Choi and Yoo {Bin Kwak} and Wu Jeong Hwang and Taekwan Kim and Ji Yoon Lee and Bo Mi Kim and Jun Soo Kwon and Yoo Bin Kwak and Wu Jeong Hwang and Taekwan Kim and Ji Yoon Lee and Bo Mi Kim and Jun Soo Kwon}, doi = {10.1016/j.pnpbp.2019.109717}, year = {2019}, date = {2019-01-01}, journal = {Progress in Neuropsychopharmacology and Biological Psychiatry}, volume = {95}, pages = {1--7}, publisher = {Elsevier}, abstract = {Background: Although internet gaming disorder (IGD) is considered an addictive disorder, evidence of the neurobiological underpinnings of IGD as an addictive disorder is currently lacking. We investigated whether attentional bias toward game-related stimuli was altered in IGD patients using an eye-tracking method during an anti-saccade task. Methods: Twenty-three IGD patients and 27 healthy control (HC) subjects participated in the anti-saccade task with game-related, neutral, and scrambled images during eye tracking. Participants rated subjective scores of valence, arousal, and craving for each image stimulus after finishing eye tracking. Mixed design analysis of variance was performed to compare the differences between eye movement latency and error rate in the pro-saccade and anti-saccade conditions according to image type across the IGD and HC groups. Results: In the anti-saccade task, the IGD group exhibited higher error rates in the case of game-related images than in neutral or scrambled images. However, ratings on valence, arousal, and craving did not vary among image types. The error rates of the HCs did not vary across image types, but higher arousal/craving and lower valence were reported with respect to the game-related images. Conclusions: Increased error rate during anti-saccade tasks with game-related stimuli in IGD may be due to disabilities in goal-directed behavior or inhibitory control, as observed in other addictive disorders. These findings suggest that attentional bias toward game-related stimuli can be a sensitive biological marker of IGD as an addictive disorder.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Although internet gaming disorder (IGD) is considered an addictive disorder, evidence of the neurobiological underpinnings of IGD as an addictive disorder is currently lacking. We investigated whether attentional bias toward game-related stimuli was altered in IGD patients using an eye-tracking method during an anti-saccade task. Methods: Twenty-three IGD patients and 27 healthy control (HC) subjects participated in the anti-saccade task with game-related, neutral, and scrambled images during eye tracking. Participants rated subjective scores of valence, arousal, and craving for each image stimulus after finishing eye tracking. Mixed design analysis of variance was performed to compare the differences between eye movement latency and error rate in the pro-saccade and anti-saccade conditions according to image type across the IGD and HC groups. Results: In the anti-saccade task, the IGD group exhibited higher error rates in the case of game-related images than in neutral or scrambled images. However, ratings on valence, arousal, and craving did not vary among image types. The error rates of the HCs did not vary across image types, but higher arousal/craving and lower valence were reported with respect to the game-related images. Conclusions: Increased error rate during anti-saccade tasks with game-related stimuli in IGD may be due to disabilities in goal-directed behavior or inhibitory control, as observed in other addictive disorders. These findings suggest that attentional bias toward game-related stimuli can be a sensitive biological marker of IGD as an addictive disorder. |
Jiyeon Lee Effect of lexical accessibility on syntactic production in aphasia: An eyetracking study Journal Article Aphasiology, pp. 1–20, 2019. @article{Lee2019b, title = {Effect of lexical accessibility on syntactic production in aphasia: An eyetracking study}, author = {Jiyeon Lee}, doi = {10.1080/02687038.2019.1665963}, year = {2019}, date = {2019-01-01}, journal = {Aphasiology}, pages = {1--20}, publisher = {Routledge}, abstract = {Background & Aims: Healthy speakers use both word-level and structure-level information to ease sentence production processes. Structural priming facilitates message-structure mapping in aphasia. However, it remains unclear if and how word-level information affects off-line and on-line sentence production in persons with aphasia (PWA). This eyetracking-while-speaking study examined the effect of lexical priming on production of syntactic (active/passive) structures in PWA. Methods: Eleven PWA and twenty healthy older adults (HOA) described transitive actions (woman pulling horse) following lexical priming, wherein the relative ease of lexical retrieval for the Agent or Theme was manipulated via an auditory probe (what is happening with the woman/horse?). It was examined whether or not PWA produce the sentence structure that allows earlier production of the primed word (e.g., passives when Theme was primed). Participants' eye fixation times to each character (Agent, Theme) were also monitored to examine if PWA show priming-induced preferential looks to one character from the earliest stage of production, consistent with word-driven planning. Results: HOA showed increased production of passives over actives in the Theme vs. Agent prime condition. In eye fixation data, HOA showed priming-induced Theme advantage from the earliest time window (picture onset-400 milliseconds). PWA also showed a significant priming effect in off-line sentence production, with this priming effect being greater for the individuals whose syntactic processing is better preserved. In eye fixation data, however, PWA showed preferential fixations to the primed character at a later stage of sentence planning (400–800 milliseconds), following equal fixation time to Agent and Theme during the earliest time window. Conclusion: HOA showed word-driven production in both off-line and real-time (eye fixations) production. Lexical accessibility effectively drove off-line syntactic production in PWA, especially for those whose syntactic capacity remains relatively preserved. However, PWA showed advanced processing of both characters in earliest eye fixation data, suggesting that successful word-driven off-line syntactic production was associated with atypical real-time sentence planning in aphasia.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background & Aims: Healthy speakers use both word-level and structure-level information to ease sentence production processes. Structural priming facilitates message-structure mapping in aphasia. However, it remains unclear if and how word-level information affects off-line and on-line sentence production in persons with aphasia (PWA). This eyetracking-while-speaking study examined the effect of lexical priming on production of syntactic (active/passive) structures in PWA. Methods: Eleven PWA and twenty healthy older adults (HOA) described transitive actions (woman pulling horse) following lexical priming, wherein the relative ease of lexical retrieval for the Agent or Theme was manipulated via an auditory probe (what is happening with the woman/horse?). It was examined whether or not PWA produce the sentence structure that allows earlier production of the primed word (e.g., passives when Theme was primed). Participants' eye fixation times to each character (Agent, Theme) were also monitored to examine if PWA show priming-induced preferential looks to one character from the earliest stage of production, consistent with word-driven planning. Results: HOA showed increased production of passives over actives in the Theme vs. Agent prime condition. In eye fixation data, HOA showed priming-induced Theme advantage from the earliest time window (picture onset-400 milliseconds). PWA also showed a significant priming effect in off-line sentence production, with this priming effect being greater for the individuals whose syntactic processing is better preserved. In eye fixation data, however, PWA showed preferential fixations to the primed character at a later stage of sentence planning (400–800 milliseconds), following equal fixation time to Agent and Theme during the earliest time window. Conclusion: HOA showed word-driven production in both off-line and real-time (eye fixations) production. Lexical accessibility effectively drove off-line syntactic production in PWA, especially for those whose syntactic capacity remains relatively preserved. However, PWA showed advanced processing of both characters in earliest eye fixation data, suggesting that successful word-driven off-line syntactic production was associated with atypical real-time sentence planning in aphasia. |
Rebekka Lencer; Li Yao; James L Reilly; Sarah K Keedy; Jennifer E McDowell; Matcheri S Keshavan; Godfrey D Pearlson; Carol A Tamminga; Elliot S Gershon; Brett A Clementz; Su Lui; John A Sweeney Alterations in intrinsic fronto-thalamo-parietal connectivity are associated with cognitive control deficits in psychotic disorders Journal Article Human Brain Mapping, 40 , pp. 163–174, 2019. @article{Lencer2019, title = {Alterations in intrinsic fronto-thalamo-parietal connectivity are associated with cognitive control deficits in psychotic disorders}, author = {Rebekka Lencer and Li Yao and James L Reilly and Sarah K Keedy and Jennifer E McDowell and Matcheri S Keshavan and Godfrey D Pearlson and Carol A Tamminga and Elliot S Gershon and Brett A Clementz and Su Lui and John A Sweeney}, doi = {10.1002/hbm.24362}, year = {2019}, date = {2019-01-01}, journal = {Human Brain Mapping}, volume = {40}, pages = {163--174}, abstract = {Despite a growing number of reports about alterations in intrinsic/resting brain activity observed in patients with psychotic disorders, their relevance to well-established cognitive control deficits in this patient group is not well understood. Totally 88 clinically stabilized patients with a psychotic disorder and 50 healthy controls participated in a resting-state magnetic resonance imaging study (rs-MRI) and performed an antisaccade task in the laboratory to assess voluntary inhibitory control ability. Deficits on this task are a well-established biomarker across psychotic disorders as we found in the present patient sample. First, regional cerebral function was evaluated by measuring the amplitude of low frequency fluctuations (ALFF) in rs-MRI BOLD signals. We found reduced ALFF in patients in regions known to be relevant to antisaccade task performance including bilateral frontal eye fields (FEF), supplementary eye fields (SEF) and thalamus. Second, areas with ALFF alterations were used as seed areas in whole-brain functional connectivity (FC) analysis. Altered FC was observed in a fronto-thalamo-parietal network that was associated with inhibition error rate in patients but not in controls. In contrast, faster time to generate a correct antisaccade was associated with FC in FEF and SEF in controls but this effect was not seen in patients. These findings establish a behavioral relevance of resting-state fMRI findings in psychotic disorders, and extend previous reports of alterations in fronto-thalamo-parietal network activation during antisaccade performance seen in task-based fMRI studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite a growing number of reports about alterations in intrinsic/resting brain activity observed in patients with psychotic disorders, their relevance to well-established cognitive control deficits in this patient group is not well understood. Totally 88 clinically stabilized patients with a psychotic disorder and 50 healthy controls participated in a resting-state magnetic resonance imaging study (rs-MRI) and performed an antisaccade task in the laboratory to assess voluntary inhibitory control ability. Deficits on this task are a well-established biomarker across psychotic disorders as we found in the present patient sample. First, regional cerebral function was evaluated by measuring the amplitude of low frequency fluctuations (ALFF) in rs-MRI BOLD signals. We found reduced ALFF in patients in regions known to be relevant to antisaccade task performance including bilateral frontal eye fields (FEF), supplementary eye fields (SEF) and thalamus. Second, areas with ALFF alterations were used as seed areas in whole-brain functional connectivity (FC) analysis. Altered FC was observed in a fronto-thalamo-parietal network that was associated with inhibition error rate in patients but not in controls. In contrast, faster time to generate a correct antisaccade was associated with FC in FEF and SEF in controls but this effect was not seen in patients. These findings establish a behavioral relevance of resting-state fMRI findings in psychotic disorders, and extend previous reports of alterations in fronto-thalamo-parietal network activation during antisaccade performance seen in task-based fMRI studies. |
Amelia K Lewis; Melanie A Porter; Tracey A Williams; Samantha Bzishvili; Kathryn N North; Jonathan M Payne Attention to faces in social context in children with neurofibromatosis type 1 Journal Article Developmental Medicine and Child Neurology, 61 (2), pp. 174–180, 2019. @article{Lewis2019, title = {Attention to faces in social context in children with neurofibromatosis type 1}, author = {Amelia K Lewis and Melanie A Porter and Tracey A Williams and Samantha Bzishvili and Kathryn N North and Jonathan M Payne}, doi = {10.1111/dmcn.13928}, year = {2019}, date = {2019-01-01}, journal = {Developmental Medicine and Child Neurology}, volume = {61}, number = {2}, pages = {174--180}, abstract = {Aim: To examine visual attention to faces within social scenes in children with neurofibromatosis type 1 (NF1) and typically developing peers. Method: Using eye-tracking technology we investigated the time taken to fixate on a face and the percentage of time spent attending to faces relative to the rest of the screen within social scenes in 24 children with NF1 (17 females, seven males; mean age 10y 4mo [SD 1y 9mo]). Results were compared with those of 24 age-matched typically developing controls (11 females, 13 males; mean age 10y 3mo [SD 2y]). Results: There was no significant between-group differences in time taken to initially fixate on a face (p=0.617); however, children with NF1 spent less time attending to faces within scenes than controls (p=0.048). Decreased attention to faces was associated with elevated autism traits in children with NF1. Interpretation: Children with NF1 spend less time attending to faces than typically developing children when presented in social scenes. Our findings contribute to a growing body of literature suggesting that abnormal face processing is a key aspect of the social-cognitive phenotype of NF1 and appears to be related to autism spectrum disorder traits. Clinicians should consider the impact of reduced attention to faces when designing and implementing treatment programmes for social dysfunction in this population.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Aim: To examine visual attention to faces within social scenes in children with neurofibromatosis type 1 (NF1) and typically developing peers. Method: Using eye-tracking technology we investigated the time taken to fixate on a face and the percentage of time spent attending to faces relative to the rest of the screen within social scenes in 24 children with NF1 (17 females, seven males; mean age 10y 4mo [SD 1y 9mo]). Results were compared with those of 24 age-matched typically developing controls (11 females, 13 males; mean age 10y 3mo [SD 2y]). Results: There was no significant between-group differences in time taken to initially fixate on a face (p=0.617); however, children with NF1 spent less time attending to faces within scenes than controls (p=0.048). Decreased attention to faces was associated with elevated autism traits in children with NF1. Interpretation: Children with NF1 spend less time attending to faces than typically developing children when presented in social scenes. Our findings contribute to a growing body of literature suggesting that abnormal face processing is a key aspect of the social-cognitive phenotype of NF1 and appears to be related to autism spectrum disorder traits. Clinicians should consider the impact of reduced attention to faces when designing and implementing treatment programmes for social dysfunction in this population. |
Ebony R Lindor; Jeroen J A van Boxtel; Nicole J Rinehart; Joanne Fielding Motor difficulties are associated with impaired perception of interactive human movement in autism spectrum disorder: A pilot study Journal Article Journal of Clinical and Experimental Neuropsychology, 41 (8), pp. 856–874, 2019. @article{Lindor2019, title = {Motor difficulties are associated with impaired perception of interactive human movement in autism spectrum disorder: A pilot study}, author = {Ebony R Lindor and Jeroen J A van Boxtel and Nicole J Rinehart and Joanne Fielding}, doi = {10.1080/13803395.2019.1634181}, year = {2019}, date = {2019-01-01}, journal = {Journal of Clinical and Experimental Neuropsychology}, volume = {41}, number = {8}, pages = {856--874}, publisher = {Routledge}, abstract = {Introduction: The ability to accurately perceive human movement is fundamental to social functioning and known to be influenced by one's own motor skills. In Autism Spectrum Disorder (ASD), there is ongoing debate about whether human movement perception is impaired. Given that motor skills vary considerably among these individuals, it may be that human movement perception is differentially affected as a function of motor proficiency. The aim of the current study was, thus, to explore whether individuals with ASD with and without motor difficulties differ in the way they visually attend to and perceive human movement. Method: Three groups of children aged 6 to 14 completed the study: an ASD group with motor difficulties (ASDMD), an ASD group without motor difficulties (ASDNMD), and a typically-developing control group (TD). All participants (N = 31) underwent eye-tracking while they viewed communicative interactions performed by two point-light actors. Primary analyses considered group differences in perceptual accuracy and gaze patterns. Results: Results revealed poorer perceptual accuracy in the ASDMD group compared to the ASDNMD and TD groups. Both ASD groups also exhibited gaze anomalies. Unlike the ASDNMD and TD groups who preferentially allocated their gaze to the actor initiating the interaction, the ASDMD group gazed at both actors equally. In contrast, the ASDNMD group shifted their gaze between the actors more frequently than the other groups. Conclusions: These preliminary findings suggest that individuals with ASD and co-occurring motor difficulties employ an atypical attentional style that may hinder accurate human movement perception, whereas those without motor difficulties may employ a compensatory attentional style that facilitates typical perception. Improving our understanding of how attention and perception are affected across the ASD spectrum has the potential to provide insight into the mechanisms that underlie the core social deficits that define this disorder.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Introduction: The ability to accurately perceive human movement is fundamental to social functioning and known to be influenced by one's own motor skills. In Autism Spectrum Disorder (ASD), there is ongoing debate about whether human movement perception is impaired. Given that motor skills vary considerably among these individuals, it may be that human movement perception is differentially affected as a function of motor proficiency. The aim of the current study was, thus, to explore whether individuals with ASD with and without motor difficulties differ in the way they visually attend to and perceive human movement. Method: Three groups of children aged 6 to 14 completed the study: an ASD group with motor difficulties (ASDMD), an ASD group without motor difficulties (ASDNMD), and a typically-developing control group (TD). All participants (N = 31) underwent eye-tracking while they viewed communicative interactions performed by two point-light actors. Primary analyses considered group differences in perceptual accuracy and gaze patterns. Results: Results revealed poorer perceptual accuracy in the ASDMD group compared to the ASDNMD and TD groups. Both ASD groups also exhibited gaze anomalies. Unlike the ASDNMD and TD groups who preferentially allocated their gaze to the actor initiating the interaction, the ASDMD group gazed at both actors equally. In contrast, the ASDNMD group shifted their gaze between the actors more frequently than the other groups. Conclusions: These preliminary findings suggest that individuals with ASD and co-occurring motor difficulties employ an atypical attentional style that may hinder accurate human movement perception, whereas those without motor difficulties may employ a compensatory attentional style that facilitates typical perception. Improving our understanding of how attention and perception are affected across the ASD spectrum has the potential to provide insight into the mechanisms that underlie the core social deficits that define this disorder. |
Ebony Lindor; Nicole Rinehart; Joanne Fielding Distractor inhibition in Autism Spectrum Disorder: Evidence of a selective impairment for individuals with co-occurring motor difficulties Journal Article Journal of Autism and Developmental Disorders, 49 (2), pp. 669–682, 2019. @article{Lindor2019a, title = {Distractor inhibition in Autism Spectrum Disorder: Evidence of a selective impairment for individuals with co-occurring motor difficulties}, author = {Ebony Lindor and Nicole Rinehart and Joanne Fielding}, doi = {10.1007/s10803-018-3744-1}, year = {2019}, date = {2019-01-01}, journal = {Journal of Autism and Developmental Disorders}, volume = {49}, number = {2}, pages = {669--682}, publisher = {Springer US}, abstract = {Although most researchers agree that individuals with Autism Spectrum Disorder (ASD) exhibit atypical attention, there is little consensus on the exact nature of their deficits. We explored whether attentional control in ASD varies as a function of motor proficiency. Nineteen children with ASD and 26 typically-developing controls completed the Movement Assessment Battery for Children and two ocular motor tasks requiring them to generate a saccade toward, and fixate, a visual target in the presence or absence of a distractor. The ASD group demonstrated poorer accuracy than typically-developing controls when distractors were present. Importantly, however, ASD symptomology was only related to poorer accuracy in individuals with motor difficulties. These findings suggest that distractor inhibition may be selectively impaired in this subgroup.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Although most researchers agree that individuals with Autism Spectrum Disorder (ASD) exhibit atypical attention, there is little consensus on the exact nature of their deficits. We explored whether attentional control in ASD varies as a function of motor proficiency. Nineteen children with ASD and 26 typically-developing controls completed the Movement Assessment Battery for Children and two ocular motor tasks requiring them to generate a saccade toward, and fixate, a visual target in the presence or absence of a distractor. The ASD group demonstrated poorer accuracy than typically-developing controls when distractors were present. Importantly, however, ASD symptomology was only related to poorer accuracy in individuals with motor difficulties. These findings suggest that distractor inhibition may be selectively impaired in this subgroup. |
Anne-Claude Luisier; Brocoli Factory; Switzerland Anne-Rapha; Elle Richoz; Junpeng Lao; Roberto Caldara; Moustafa Bensafi Visual and hedonic perception of food stimuli in children with autism spectrum disorders and their relationship to food neophobia Journal Article Perception, 48 (3), pp. 197–213, 2019. @article{Luisier2019, title = {Visual and hedonic perception of food stimuli in children with autism spectrum disorders and their relationship to food neophobia}, author = {Anne-Claude Luisier and Brocoli Factory and Switzerland Anne-Rapha and Elle Richoz and Junpeng Lao and Roberto Caldara and Moustafa Bensafi}, doi = {10.1177/0301006619828300}, year = {2019}, date = {2019-01-01}, journal = {Perception}, volume = {48}, number = {3}, pages = {197--213}, abstract = {The present study examined whether children with autism spectrum disorder (ASD) and typically developing (TD) children differed in visual perception of food stimuli at both sensorimotor and affective levels. A potential link between visual perception and food neophobia was also investigated. To these aims, 11 children with ASD and 11 TD children were tested. Visual pictures of food were used, and food neophobia was assessed by the parents. Results revealed that children with ASD explored visually longer food stimuli than TD children. Complementary analyses revealed that whereas TD children explored more multiple-item dishes (vs. simple-item dishes), children with ASD explored all the dishes in a similar way. In addition, children with ASD gave more negative appreciation in general. Moreover, hedonic rating was negatively cor- related with food neophobia scores in children with ASD, but not in TD children. In sum, we show here that children with ASD have more difficulty than TD children in liking a food when presented visually. Our findings also suggest that a prominent factor that needs to be considered is time management during the food choice process. They also provide new ways of measuring and understanding food neophobia in children with ASD.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study examined whether children with autism spectrum disorder (ASD) and typically developing (TD) children differed in visual perception of food stimuli at both sensorimotor and affective levels. A potential link between visual perception and food neophobia was also investigated. To these aims, 11 children with ASD and 11 TD children were tested. Visual pictures of food were used, and food neophobia was assessed by the parents. Results revealed that children with ASD explored visually longer food stimuli than TD children. Complementary analyses revealed that whereas TD children explored more multiple-item dishes (vs. simple-item dishes), children with ASD explored all the dishes in a similar way. In addition, children with ASD gave more negative appreciation in general. Moreover, hedonic rating was negatively cor- related with food neophobia scores in children with ASD, but not in TD children. In sum, we show here that children with ASD have more difficulty than TD children in liking a food when presented visually. Our findings also suggest that a prominent factor that needs to be considered is time management during the food choice process. They also provide new ways of measuring and understanding food neophobia in children with ASD. |
Inga Meyhöfer; Anna-Maria Kasparbauer; Maria Steffens; Ulrich Ettinger Effects of nicotine on smooth pursuit eye movements in healthy non-smokers Journal Article Psychopharmacology, 236 , pp. 2259–2271, 2019. @article{Meyhoefer2019, title = {Effects of nicotine on smooth pursuit eye movements in healthy non-smokers}, author = {Inga Meyhöfer and Anna-Maria Kasparbauer and Maria Steffens and Ulrich Ettinger}, doi = {10.1007/s00213-019-05223-1}, year = {2019}, date = {2019-01-01}, journal = {Psychopharmacology}, volume = {236}, pages = {2259--2271}, abstract = {Rationale: The non-selective nicotinic acetylcholine receptor (nAChR) agonist nicotine has been argued to improve attention via enhanced filtering of irrelevant stimuli. Here, we tested this hypothesis in the context of smooth pursuit eye movements (SPEMs), an oculomotor function previously shown to improve with nicotine in some but not all studies. Objectives: In order to test whether nicotine improves performance particularly when the inhibition of distracting stimuli is required, SPEM was elicited in conditions with or without peripheral distractors. Additionally, different target frequencies were employed in order to parametrically vary general processing demands on the SPEM system. Methods: Healthy adult non-smokers (N = 18 females}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rationale: The non-selective nicotinic acetylcholine receptor (nAChR) agonist nicotine has been argued to improve attention via enhanced filtering of irrelevant stimuli. Here, we tested this hypothesis in the context of smooth pursuit eye movements (SPEMs), an oculomotor function previously shown to improve with nicotine in some but not all studies. Objectives: In order to test whether nicotine improves performance particularly when the inhibition of distracting stimuli is required, SPEM was elicited in conditions with or without peripheral distractors. Additionally, different target frequencies were employed in order to parametrically vary general processing demands on the SPEM system. Methods: Healthy adult non-smokers (N = 18 females |
Stephanie M Montenegro; Jay A Edelman Impact of task-specific training on saccadic eye movement performance Journal Article Journal of Neurophysiology, 122 , pp. 1661–1674, 2019. @article{Montenegro2019, title = {Impact of task-specific training on saccadic eye movement performance}, author = {Stephanie M Montenegro and Jay A Edelman}, doi = {10.1152/jn.00020.2019.-Prosaccades}, year = {2019}, date = {2019-01-01}, journal = {Journal of Neurophysiology}, volume = {122}, pages = {1661--1674}, abstract = {Prosaccades are saccadic eye movements made reflexively in response to the sudden appearance of visual stimuli, whereas antisaccades are saccades that are directed to a location opposite a stimulus. Bibi and Edelman (Bibi R, Edelman JA. J Neurophysiol 102: 3101-3110, 2009) demonstrated that decreases in reaction time resulting from training prosaccades along one spatial axis (horizontal or vertical) could transfer to prosaccades made along the other axis. To help determine whether visual or motor-related processes underlie this facilitation, in the present study we trained participants to make prosaccades and probed their performance (reaction time, error rate) on antisaccade trials and vice versa. Subjects were probed for the effects of training on saccade performance before, during, and after 12 sessions of training. Training on prosaccades improved performance on both pro-and antisaccade tasks. Antisaccade training, with either a classic step task or a gap task, improved performance on gap prosaccades, though by less than it improved antisaccade performance, but had limited effect on an overlap prosac-cade task. Across all subjects, training on one task only rarely had an adverse impact on an untrained task. These findings suggest that the predominant effect of saccade training is to facilitate fixation disengagement and motor preparation processes while having little impact on visual input to the saccadic system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Prosaccades are saccadic eye movements made reflexively in response to the sudden appearance of visual stimuli, whereas antisaccades are saccades that are directed to a location opposite a stimulus. Bibi and Edelman (Bibi R, Edelman JA. J Neurophysiol 102: 3101-3110, 2009) demonstrated that decreases in reaction time resulting from training prosaccades along one spatial axis (horizontal or vertical) could transfer to prosaccades made along the other axis. To help determine whether visual or motor-related processes underlie this facilitation, in the present study we trained participants to make prosaccades and probed their performance (reaction time, error rate) on antisaccade trials and vice versa. Subjects were probed for the effects of training on saccade performance before, during, and after 12 sessions of training. Training on prosaccades improved performance on both pro-and antisaccade tasks. Antisaccade training, with either a classic step task or a gap task, improved performance on gap prosaccades, though by less than it improved antisaccade performance, but had limited effect on an overlap prosac-cade task. Across all subjects, training on one task only rarely had an adverse impact on an untrained task. These findings suggest that the predominant effect of saccade training is to facilitate fixation disengagement and motor preparation processes while having little impact on visual input to the saccadic system. |
Cristian Morales; Suril Gohel; Xiaobo Li; Mitchell Scheiman; Bharat B Biswal; Elio M Santos; Chang Yaramothu; Tara L Alvarez Test–retest reliability of functional magnetic resonance imaging activation for a vergence eye movement task Journal Article Neuroscience Bulletin, pp. 1–13, 2019. @article{Morales2019, title = {Test–retest reliability of functional magnetic resonance imaging activation for a vergence eye movement task}, author = {Cristian Morales and Suril Gohel and Xiaobo Li and Mitchell Scheiman and Bharat B Biswal and Elio M Santos and Chang Yaramothu and Tara L Alvarez}, doi = {10.1007/s12264-019-00455-9}, year = {2019}, date = {2019-01-01}, journal = {Neuroscience Bulletin}, pages = {1--13}, publisher = {Springer Singapore}, abstract = {Vergence eye movements are the inward and outward rotation of the eyes responsible for binocular coordination. While studies have mapped and investigated the neural substrates of vergence, it is not well understood whether vergence eye movements evoke the blood oxygen level-dependent signal reliably in separate experimental visits. The test–retest reliability of stimulus-induced vergence eye movement tasks during a functional magnetic resonance imaging (fMRI) experiment is important for future randomized clinical trials (RCTs). In this study, we established region of interest (ROI) masks for the vergence neural circuit. Twenty-seven binocularly normal young adults participated in two functional imaging sessions measured on different days on the same 3T Siemens scanner. The fMRI experiments used a block design of sustained visual fixation and rest blocks interleaved between task blocks that stimulated eight or four vergence eye movements. The test–retest reliability of task-activation was assessed using the intraclass correlation coefficient (ICC), and that of spatial extent was assessed using the Dice coefficient. Functional activation during the vergence eye movement task of eight movements compared to rest was repeatable within the primary visual cortex (ICC = 0.8), parietal eye fields (ICC = 0.6), supplementary eye field (ICC = 0.5), frontal eye fields (ICC = 0.5), and oculomotor vermis (ICC = 0.6). The results demonstrate significant test–retest reliability in the ROIs of the vergence neural substrates for functional activation magnitude and spatial extent using the stimulus protocol of a task block stimulating eight vergence eye movements compared to sustained fixation. These ROIs can be used in future longitudinal RCTs to study patient populations with vergence dysfunctions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Vergence eye movements are the inward and outward rotation of the eyes responsible for binocular coordination. While studies have mapped and investigated the neural substrates of vergence, it is not well understood whether vergence eye movements evoke the blood oxygen level-dependent signal reliably in separate experimental visits. The test–retest reliability of stimulus-induced vergence eye movement tasks during a functional magnetic resonance imaging (fMRI) experiment is important for future randomized clinical trials (RCTs). In this study, we established region of interest (ROI) masks for the vergence neural circuit. Twenty-seven binocularly normal young adults participated in two functional imaging sessions measured on different days on the same 3T Siemens scanner. The fMRI experiments used a block design of sustained visual fixation and rest blocks interleaved between task blocks that stimulated eight or four vergence eye movements. The test–retest reliability of task-activation was assessed using the intraclass correlation coefficient (ICC), and that of spatial extent was assessed using the Dice coefficient. Functional activation during the vergence eye movement task of eight movements compared to rest was repeatable within the primary visual cortex (ICC = 0.8), parietal eye fields (ICC = 0.6), supplementary eye field (ICC = 0.5), frontal eye fields (ICC = 0.5), and oculomotor vermis (ICC = 0.6). The results demonstrate significant test–retest reliability in the ROIs of the vergence neural substrates for functional activation magnitude and spatial extent using the stimulus protocol of a task block stimulating eight vergence eye movements compared to sustained fixation. These ROIs can be used in future longitudinal RCTs to study patient populations with vergence dysfunctions. |
Kentaro Morita; Kenichiro Miura; Michiko Fujimoto; Hidenaga Yamamori; Yuka Yasuda; Noriko Kudo; Hirotsugu Azechi; Naohiro Okada; Daisuke Koshiyama; Manabu Ikeda; Kiyoto Kasai; Ryota Hashimoto Eye movement abnormalities and their association with cognitive impairments in schizophrenia Journal Article Schizophrenia Research, 209 , pp. 255–262, 2019. @article{Morita2019, title = {Eye movement abnormalities and their association with cognitive impairments in schizophrenia}, author = {Kentaro Morita and Kenichiro Miura and Michiko Fujimoto and Hidenaga Yamamori and Yuka Yasuda and Noriko Kudo and Hirotsugu Azechi and Naohiro Okada and Daisuke Koshiyama and Manabu Ikeda and Kiyoto Kasai and Ryota Hashimoto}, doi = {10.1016/j.schres.2018.12.051}, year = {2019}, date = {2019-01-01}, journal = {Schizophrenia Research}, volume = {209}, pages = {255--262}, publisher = {Elsevier B.V.}, abstract = {Background: Eye movement abnormalities have been identified in schizophrenia; however, their relevance to cognition is still unknown. In this study, we explored the general relationship between eye movements and cognitive function. Methods: The three eye movement measures (scanpath length, horizontal position gain, and duration of fixations) that were previously reported to be useful in distinguishing subjects with schizophrenia from healthy subjects, as well as Wechsler Adult Intelligence Scale-III (WAIS-III) scores, were collected and tested for association in 113 subjects with schizophrenia and 404 healthy subjects. Results: Scanpath length was positively correlated with matrix reasoning and digit symbol coding in subjects with schizophrenia and correlated with vocabulary and symbol search in healthy subjects. Upon testing for interaction effects of diagnosis and scanpath length on correlated WAIS-III scores, a significant interaction effect was only observed for matrix reasoning. The positive correlation between scanpath length and matrix reasoning, which was specific to subjects with schizophrenia, remained significant after controlling for demographic confounders such as medication and negative symptoms. No correlation was observed between the two other eye movement measures and any of the WAIS-III scores. Conclusions: Herein, we reveal novel findings on the association between eye-movement-based measures of visual exploration and cognitive scores requiring visual search in subjects with schizophrenia and in healthy subjects. The association between scanpath length and matrix reasoning, a measure of perceptual organization in subjects with schizophrenia, implies the existence of common cognitive processes, and subjects with longer scanpath length may be advantageous in performance of perceptual organization tasks.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Eye movement abnormalities have been identified in schizophrenia; however, their relevance to cognition is still unknown. In this study, we explored the general relationship between eye movements and cognitive function. Methods: The three eye movement measures (scanpath length, horizontal position gain, and duration of fixations) that were previously reported to be useful in distinguishing subjects with schizophrenia from healthy subjects, as well as Wechsler Adult Intelligence Scale-III (WAIS-III) scores, were collected and tested for association in 113 subjects with schizophrenia and 404 healthy subjects. Results: Scanpath length was positively correlated with matrix reasoning and digit symbol coding in subjects with schizophrenia and correlated with vocabulary and symbol search in healthy subjects. Upon testing for interaction effects of diagnosis and scanpath length on correlated WAIS-III scores, a significant interaction effect was only observed for matrix reasoning. The positive correlation between scanpath length and matrix reasoning, which was specific to subjects with schizophrenia, remained significant after controlling for demographic confounders such as medication and negative symptoms. No correlation was observed between the two other eye movement measures and any of the WAIS-III scores. Conclusions: Herein, we reveal novel findings on the association between eye-movement-based measures of visual exploration and cognitive scores requiring visual search in subjects with schizophrenia and in healthy subjects. The association between scanpath length and matrix reasoning, a measure of perceptual organization in subjects with schizophrenia, implies the existence of common cognitive processes, and subjects with longer scanpath length may be advantageous in performance of perceptual organization tasks. |
Judith Nicolas; Aurélie Bidet-Caulet; Denis Pélisson Inducing oculomotor plasticity to disclose the functional link between voluntary saccades and endogenous attention deployed perifoveally Journal Article Scientific Reports, 9 , pp. 1–12, 2019. @article{Nicolas2019, title = {Inducing oculomotor plasticity to disclose the functional link between voluntary saccades and endogenous attention deployed perifoveally}, author = {Judith Nicolas and Aurélie Bidet-Caulet and Denis Pélisson}, doi = {10.1038/s41598-019-54256-1}, year = {2019}, date = {2019-01-01}, journal = {Scientific Reports}, volume = {9}, pages = {1--12}, abstract = {To what extent oculomotor and attention systems are linked remains strongly debated. Previous studies suggested that saccadic adaptation, a well-studied model of oculomotor plasticity, and orienting of attention rely on overlapping networks in the parietal cortex and can functionally interact. Using a Posner-like paradigm in healthy human subjects, we demonstrate for the first time that saccadic adaptation boosts endogenous attention orienting. Indeed, the discrimination of perifoveal targets benefits more from central cues after backward adaptation of leftward voluntary saccades than after a control saccade task. We propose that the overlap of underlying neural networks actually consists of neuronal populations co-activated by oculomotor plasticity and endogenous attention deployed perifoveally. The functional coupling demonstrated here plaids for conceptual models not belonging to the framework of the premotor theory of attention as the latter has been rejected precisely for this voluntary/endogenous modality. These results also open new perspective for rehabilitation of visuo-attentional deficits.}, keywords = {}, pubstate = {published}, tppubtype = {article} } To what extent oculomotor and attention systems are linked remains strongly debated. Previous studies suggested that saccadic adaptation, a well-studied model of oculomotor plasticity, and orienting of attention rely on overlapping networks in the parietal cortex and can functionally interact. Using a Posner-like paradigm in healthy human subjects, we demonstrate for the first time that saccadic adaptation boosts endogenous attention orienting. Indeed, the discrimination of perifoveal targets benefits more from central cues after backward adaptation of leftward voluntary saccades than after a control saccade task. We propose that the overlap of underlying neural networks actually consists of neuronal populations co-activated by oculomotor plasticity and endogenous attention deployed perifoveally. The functional coupling demonstrated here plaids for conceptual models not belonging to the framework of the premotor theory of attention as the latter has been rejected precisely for this voluntary/endogenous modality. These results also open new perspective for rehabilitation of visuo-attentional deficits. |
Judith Nicolas; Aline Bompas; Romain Bouet; Olivier Sillan; Eric Koun; Christian Urquizar; Aurélie Bidet-Caulet; Denis Pélisson Saccadic adaptation boosts ongoing gamma activity in a subsequent visuoattentional task Journal Article Cerebral Cortex, 29 (9), pp. 3606–3617, 2019. @article{Nicolas2019a, title = {Saccadic adaptation boosts ongoing gamma activity in a subsequent visuoattentional task}, author = {Judith Nicolas and Aline Bompas and Romain Bouet and Olivier Sillan and Eric Koun and Christian Urquizar and Aurélie Bidet-Caulet and Denis Pélisson}, doi = {10.1093/cercor/bhy241}, year = {2019}, date = {2019-01-01}, journal = {Cerebral Cortex}, volume = {29}, number = {9}, pages = {3606--3617}, abstract = {Attention and saccadic adaptation (SA) are critical components of visual perception, the former enhancing sensory processing of selected objects, the latter maintaining the eye movements accuracy toward them. Recent studies propelled the hypothesis of a tight functional coupling between these mechanisms, possibly due to shared neural substrates. Here, we used magnetoencephalography to investigate for the first time the neurophysiological bases of this coupling and of SA per se. We compared visual discrimination performance of 12 healthy subjects before and after SA. Eye movements and magnetic signals were recorded continuously. Analyses focused on gamma band activity (GBA) during the pretarget period of the discrimination and the saccadic tasks. We found that GBA increases after SA. This increase was found in the right hemisphere for both postadaptation saccadic and discrimination tasks. For the latter, GBA also increased in the left hemisphere. We conclude that oculomotor plasticity involves GBA modulation within an extended neural network which persists after SA, suggesting a possible role of gamma oscillations in the coupling between SA and attention.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Attention and saccadic adaptation (SA) are critical components of visual perception, the former enhancing sensory processing of selected objects, the latter maintaining the eye movements accuracy toward them. Recent studies propelled the hypothesis of a tight functional coupling between these mechanisms, possibly due to shared neural substrates. Here, we used magnetoencephalography to investigate for the first time the neurophysiological bases of this coupling and of SA per se. We compared visual discrimination performance of 12 healthy subjects before and after SA. Eye movements and magnetic signals were recorded continuously. Analyses focused on gamma band activity (GBA) during the pretarget period of the discrimination and the saccadic tasks. We found that GBA increases after SA. This increase was found in the right hemisphere for both postadaptation saccadic and discrimination tasks. For the latter, GBA also increased in the left hemisphere. We conclude that oculomotor plasticity involves GBA modulation within an extended neural network which persists after SA, suggesting a possible role of gamma oscillations in the coupling between SA and attention. |
J A Nij Bijvank; L J van Rijn; M Kamminga; H S Tan; B M J Uitdehaag; A Petzold; L J Balk Saccadic fatigability in the oculomotor system Journal Article Journal of the Neurological Sciences, 402 (]), pp. 167–174, 2019. @article{NijBijvank2019, title = {Saccadic fatigability in the oculomotor system}, author = {J A {Nij Bijvank} and L J van Rijn and M Kamminga and H S Tan and B M J Uitdehaag and A Petzold and L J Balk}, doi = {10.1016/j.jns.2019.05.024}, year = {2019}, date = {2019-01-01}, journal = {Journal of the Neurological Sciences}, volume = {402}, number = {]}, pages = {167--174}, abstract = {Background: Fatigue is one of the most common and disabling symptoms in multiple sclerosis (MS), but challenging to quantify. This prospective study investigated if repeated saccadic eye movements enable measurement of oculomotor fatigability and can reflect on perceived fatigue in MS. Methods: A standardized infrared oculography protocol (DEMoNS) was used for quantifying saccades in MS patients and healthy controls which included a first and a repeated pro-saccadic task (FPT and RPT). Saccadic peak velocity, latency, gain, area under the curve (AUC) and peak velocity divided by amplitude (Pv/Am) were calculated in both tasks. Perception based fatigue was assessed using the Checklist Individual Strength and the Neurological Fatigue Index (NFI). Linear regression models were used for assessing the relation between saccadic parameters and perceived fatigue. Results: This study included 181 MS patients and 58 healthy controls subjects. From FPT to RPT, there were significant changes in saccadic parameters. Latency of both tasks was significantly related to NFI summary score (FPT: $beta$ = 0.022}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Fatigue is one of the most common and disabling symptoms in multiple sclerosis (MS), but challenging to quantify. This prospective study investigated if repeated saccadic eye movements enable measurement of oculomotor fatigability and can reflect on perceived fatigue in MS. Methods: A standardized infrared oculography protocol (DEMoNS) was used for quantifying saccades in MS patients and healthy controls which included a first and a repeated pro-saccadic task (FPT and RPT). Saccadic peak velocity, latency, gain, area under the curve (AUC) and peak velocity divided by amplitude (Pv/Am) were calculated in both tasks. Perception based fatigue was assessed using the Checklist Individual Strength and the Neurological Fatigue Index (NFI). Linear regression models were used for assessing the relation between saccadic parameters and perceived fatigue. Results: This study included 181 MS patients and 58 healthy controls subjects. From FPT to RPT, there were significant changes in saccadic parameters. Latency of both tasks was significantly related to NFI summary score (FPT: $beta$ = 0.022 |
Kaiser Niknam; Amir Akbarian; Kelsey Clark; Yasin Zamani; Behrad Noudoost; Neda Nategh Characterizing and dissociating multiple time-varying modulatory computations influencing neuronal activity Journal Article 15 (9), pp. 1–38, 2019. @article{Niknam2019, title = {Characterizing and dissociating multiple time-varying modulatory computations influencing neuronal activity}, author = {Kaiser Niknam and Amir Akbarian and Kelsey Clark and Yasin Zamani and Behrad Noudoost and Neda Nategh}, doi = {10.1371/journal.pcbi.1007275}, year = {2019}, date = {2019-01-01}, booktitle = {PLoS Computational Biology}, volume = {15}, number = {9}, pages = {1--38}, abstract = {In many brain areas, sensory responses are heavily modulated by factors including attentional state, context, reward history, motor preparation, learned associations, and other cognitive variables. Modelling the effect of these modulatory factors on sensory responses has proven challenging, mostly due to the time-varying and nonlinear nature of the underlying computations. Here we present a computational model capable of capturing and dissociating multiple time-varying modulatory effects on neuronal responses on the order of milliseconds. The model's performance is tested on extrastriate perisaccadic visual responses in nonhuman primates. Visual neurons respond to stimuli presented around the time of saccades differently than during fixation. These perisaccadic changes include sensitivity to the stimuli presented at locations outside the neuron's receptive field, which suggests a contribution of multiple sources to perisaccadic response generation. Current computational approaches cannot quantitatively characterize the contribution of each modulatory source in response generation, mainly due to the very short timescale on which the saccade takes place. In this study, we use a high spatiotemporal resolution experimental paradigm along with a novel extension of the generalized linear model framework (GLM), termed the sparse-variable GLM, to allow for time-varying model parameters representing the temporal evolution of the system with a resolution on the order of milliseconds. We used this model framework to precisely map the temporal evolution of the spatiotemporal receptive field of visual neurons in the middle temporal area during the execution of a saccade. Moreover, an extended model based on a factorization of the sparse-variable GLM allowed us to disassociate and quantify the contribution of individual sources to the perisaccadic response. Our results show that our novel framework can precisely capture the changes in sensitivity of neurons around the time of saccades, and provide a general framework to quantitatively track the role of multiple modulatory sources over time.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In many brain areas, sensory responses are heavily modulated by factors including attentional state, context, reward history, motor preparation, learned associations, and other cognitive variables. Modelling the effect of these modulatory factors on sensory responses has proven challenging, mostly due to the time-varying and nonlinear nature of the underlying computations. Here we present a computational model capable of capturing and dissociating multiple time-varying modulatory effects on neuronal responses on the order of milliseconds. The model's performance is tested on extrastriate perisaccadic visual responses in nonhuman primates. Visual neurons respond to stimuli presented around the time of saccades differently than during fixation. These perisaccadic changes include sensitivity to the stimuli presented at locations outside the neuron's receptive field, which suggests a contribution of multiple sources to perisaccadic response generation. Current computational approaches cannot quantitatively characterize the contribution of each modulatory source in response generation, mainly due to the very short timescale on which the saccade takes place. In this study, we use a high spatiotemporal resolution experimental paradigm along with a novel extension of the generalized linear model framework (GLM), termed the sparse-variable GLM, to allow for time-varying model parameters representing the temporal evolution of the system with a resolution on the order of milliseconds. We used this model framework to precisely map the temporal evolution of the spatiotemporal receptive field of visual neurons in the middle temporal area during the execution of a saccade. Moreover, an extended model based on a factorization of the sparse-variable GLM allowed us to disassociate and quantify the contribution of individual sources to the perisaccadic response. Our results show that our novel framework can precisely capture the changes in sensitivity of neurons around the time of saccades, and provide a general framework to quantitatively track the role of multiple modulatory sources over time. |
Michael A Paradiso; Seth Akers-Campbell; Octavio Ruiz; James E Niemeyer; Stuart Geman; Jackson Loper Transsacadic information and corollary discharge in local field potentials of macaque V1 Journal Article Frontiers in Integrative Neuroscience, 12 , pp. 1–18, 2019. @article{Paradiso2019, title = {Transsacadic information and corollary discharge in local field potentials of macaque V1}, author = {Michael A Paradiso and Seth Akers-Campbell and Octavio Ruiz and James E Niemeyer and Stuart Geman and Jackson Loper}, doi = {10.3389/fnint.2018.00063}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Integrative Neuroscience}, volume = {12}, pages = {1--18}, abstract = {Approximately three times per second, human visual perception is interrupted by a saccadic eye movement. In addition to taking the eyes to a new location, several lines of evidence suggest that the saccades play multiple roles in visual perception. Indeed, it may be crucial that visual processing is informed about movements of the eyes in order to analyze visual input distinctly and efficiently on each fixation and preserve stable visual perception of the world across saccades. A variety of studies has demonstrated that activity in multiple brain areas is modulated by saccades. The hypothesis tested here is that these signals carry significant information that could be used in visual processing. To test this hypothesis, local field potentials (LFPs) were simultaneously recorded from multiple electrodes in macaque primary visual cortex (V1); support vector machines (SVMs) were used to classify the peri-saccadic LFPs. We find that LFPs in area V1 carry information that can be used to distinguish neural activity associated with fixations from saccades, precisely estimate the onset time of fixations, and reliably infer the directions of saccades. This information may be used by the brain in processes including visual stability, saccadic suppression, receptive field (RF) remapping, fixation amplification, and trans-saccadic visual perception.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Approximately three times per second, human visual perception is interrupted by a saccadic eye movement. In addition to taking the eyes to a new location, several lines of evidence suggest that the saccades play multiple roles in visual perception. Indeed, it may be crucial that visual processing is informed about movements of the eyes in order to analyze visual input distinctly and efficiently on each fixation and preserve stable visual perception of the world across saccades. A variety of studies has demonstrated that activity in multiple brain areas is modulated by saccades. The hypothesis tested here is that these signals carry significant information that could be used in visual processing. To test this hypothesis, local field potentials (LFPs) were simultaneously recorded from multiple electrodes in macaque primary visual cortex (V1); support vector machines (SVMs) were used to classify the peri-saccadic LFPs. We find that LFPs in area V1 carry information that can be used to distinguish neural activity associated with fixations from saccades, precisely estimate the onset time of fixations, and reliably infer the directions of saccades. This information may be used by the brain in processes including visual stability, saccadic suppression, receptive field (RF) remapping, fixation amplification, and trans-saccadic visual perception. |
Adam J Parker; Timothy J Slattery; Julie A Kirkby Return-sweep saccades during reading in adults and children Journal Article Vision Research, 155 , pp. 35–43, 2019. @article{Parker2019b, title = {Return-sweep saccades during reading in adults and children}, author = {Adam J Parker and Timothy J Slattery and Julie A Kirkby}, doi = {10.1016/j.visres.2018.12.007}, year = {2019}, date = {2019-01-01}, journal = {Vision Research}, volume = {155}, pages = {35--43}, publisher = {Elsevier}, abstract = {During reading, eye movement patterns differ between children and adults. Children make more fixations that are longer in duration and make shorter saccades. Return-sweeps are saccadic eye movements that move a reader's fixation to a new line of text. Return-sweeps move fixation further than intra-line saccades and often undershoot their target. This necessitates a corrective saccade to bring fixation closer to the start of the line. There have been few empirical investigations of return-sweep saccades in adults, and even fewer in children. In the present study, we examined return-sweeps of 47 adults and 48 children who read identical multiline texts. We found that children launch their return-sweeps closer to the end of the line and target a position closer to the left margin. Therefore, children fixate more extreme positions on the screen when reading for comprehension. Furthermore, children required a corrective saccade following a return-sweep more often than adults. Analysis of the duration of the fixation preceding the corrective saccade indicated that children are as efficient as adults at responding to retinal feedback following a saccade. Rather than consider differences in adult's and children's return-sweep behaviour an artefact of oculomotor control, we believe that these differences represent adult's ability to utilise parafoveal processing to encode text at extreme positions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } During reading, eye movement patterns differ between children and adults. Children make more fixations that are longer in duration and make shorter saccades. Return-sweeps are saccadic eye movements that move a reader's fixation to a new line of text. Return-sweeps move fixation further than intra-line saccades and often undershoot their target. This necessitates a corrective saccade to bring fixation closer to the start of the line. There have been few empirical investigations of return-sweep saccades in adults, and even fewer in children. In the present study, we examined return-sweeps of 47 adults and 48 children who read identical multiline texts. We found that children launch their return-sweeps closer to the end of the line and target a position closer to the left margin. Therefore, children fixate more extreme positions on the screen when reading for comprehension. Furthermore, children required a corrective saccade following a return-sweep more often than adults. Analysis of the duration of the fixation preceding the corrective saccade indicated that children are as efficient as adults at responding to retinal feedback following a saccade. Rather than consider differences in adult's and children's return-sweep behaviour an artefact of oculomotor control, we believe that these differences represent adult's ability to utilise parafoveal processing to encode text at extreme positions. |
Matthew S Peterson; Shane P Kelly; Eric J Blumberg Saccadic eye movements smear spatial working memory Journal Article Journal of Experimental Psychology: Human Perception and Performance, 45 (2), pp. 255–263, 2019. @article{Peterson2019a, title = {Saccadic eye movements smear spatial working memory}, author = {Matthew S Peterson and Shane P Kelly and Eric J Blumberg}, doi = {10.1037/xhp0000596}, year = {2019}, date = {2019-01-01}, journal = {Journal of Experimental Psychology: Human Perception and Performance}, volume = {45}, number = {2}, pages = {255--263}, abstract = {Why do saccades interfere with spatial working memory? One possibility is that attention and saccades are tightly coupled, and performing a saccade momentarily removes attention from spatial working memory, degrading the memory representation. This cannot be the entire explanation, because saccades cause greater interference than do covert attentional shifts (Lawrence, Myerson, & Abrams, 2004). In addition, this saccadic degradation is limited to spatial but not object, configural, or verbal representations. We propose that saccadic remapping is partially responsible for this increased interference. To test this, we used a spatial change detection task, and during the retention interval, participants either performed a central task, a peripheral task without an eye movement, or a peripheral task that required a saccade. Using the method of constant stimuli allowed us to fit psychophysical functions in which we derived measures of spatial memory precision, guessing, and response bias. It is important that we found a directionally specific loss of memory precision, such that memory representations were less precise along the axis of the saccade. This was beyond the general loss of precision we found for covert shifts, suggesting that part of the effect is because of remapping. Saccades also increased guessing, but unlike the loss of precision, the effect was nondirectional.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Why do saccades interfere with spatial working memory? One possibility is that attention and saccades are tightly coupled, and performing a saccade momentarily removes attention from spatial working memory, degrading the memory representation. This cannot be the entire explanation, because saccades cause greater interference than do covert attentional shifts (Lawrence, Myerson, & Abrams, 2004). In addition, this saccadic degradation is limited to spatial but not object, configural, or verbal representations. We propose that saccadic remapping is partially responsible for this increased interference. To test this, we used a spatial change detection task, and during the retention interval, participants either performed a central task, a peripheral task without an eye movement, or a peripheral task that required a saccade. Using the method of constant stimuli allowed us to fit psychophysical functions in which we derived measures of spatial memory precision, guessing, and response bias. It is important that we found a directionally specific loss of memory precision, such that memory representations were less precise along the axis of the saccade. This was beyond the general loss of precision we found for covert shifts, suggesting that part of the effect is because of remapping. Saccades also increased guessing, but unlike the loss of precision, the effect was nondirectional. |
Sohir Rahmouni; Laurent Madelain Vision Research, 160 , pp. 82–98, 2019. @article{Rahmouni2019, title = {Inter-individual variability and consistency of saccade adaptation in oblique saccades: Amplitude increase and decrease in the horizontal or vertical saccade component}, author = {Sohir Rahmouni and Laurent Madelain}, doi = {10.1016/j.visres.2019.05.001}, year = {2019}, date = {2019-01-01}, journal = {Vision Research}, volume = {160}, pages = {82--98}, publisher = {Elsevier}, abstract = {Despite changes in the physical structures controlling the eyes, saccades, the rapid eye movements used to explore the visual environment, remain accurate throughout the lifetime. The process underlying this sensorimotor adaptation is studied using a double step paradigm: an intra-saccadic target displacement introduces a systematic position error which triggers changes in saccadic amplitude or direction across trials. Numerous researches on this saccade adaptation have been conducted, but the level of inter-individual variability and consistency in saccade gain change and how it relates to increase- or decrease-amplitude paradigms is not fully described. We conducted experiments in four groups of 25 participants with 800 trials per participant, including 200 baseline trials and 200 recovery trials. We used four distinct double-step paradigms that differed by the intra-saccadic target-step leading to either a horizontal (Backward or Forward) or vertical (Upward or Downward) gain modulation. Across experiments 95% of the participants exhibited adaptation, revealing the consistency of this phenomenon. We observed strong inter-individual differences, both in the extent and rate of adaptation, which were not correlated with the individual baseline saccades characteristics. As previously reported, the rates of adaptation were higher for gain decrease than for gain increase experiments but the final extent of adaptation were similar. Our results also support the view that adaptation of oblique saccades occurs where the saccade command is represented as a vector. Finally, at the individual level, we did not observe systematic changes in the saccade metrics in relation to adaptation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite changes in the physical structures controlling the eyes, saccades, the rapid eye movements used to explore the visual environment, remain accurate throughout the lifetime. The process underlying this sensorimotor adaptation is studied using a double step paradigm: an intra-saccadic target displacement introduces a systematic position error which triggers changes in saccadic amplitude or direction across trials. Numerous researches on this saccade adaptation have been conducted, but the level of inter-individual variability and consistency in saccade gain change and how it relates to increase- or decrease-amplitude paradigms is not fully described. We conducted experiments in four groups of 25 participants with 800 trials per participant, including 200 baseline trials and 200 recovery trials. We used four distinct double-step paradigms that differed by the intra-saccadic target-step leading to either a horizontal (Backward or Forward) or vertical (Upward or Downward) gain modulation. Across experiments 95% of the participants exhibited adaptation, revealing the consistency of this phenomenon. We observed strong inter-individual differences, both in the extent and rate of adaptation, which were not correlated with the individual baseline saccades characteristics. As previously reported, the rates of adaptation were higher for gain decrease than for gain increase experiments but the final extent of adaptation were similar. Our results also support the view that adaptation of oblique saccades occurs where the saccade command is represented as a vector. Finally, at the individual level, we did not observe systematic changes in the saccade metrics in relation to adaptation. |
Meike Ramon; Nayla Sokhn; Roberto Caldara Decisional space modulates visual categorization – Evidence from saccadic reaction times Journal Article Cognition, 186 , pp. 42–49, 2019. @article{Ramon2019, title = {Decisional space modulates visual categorization – Evidence from saccadic reaction times}, author = {Meike Ramon and Nayla Sokhn and Roberto Caldara}, doi = {10.1523/JNEUROSCI.2591-18.2018}, year = {2019}, date = {2019-01-01}, journal = {Cognition}, volume = {186}, pages = {42--49}, publisher = {Society for Neuroscience}, abstract = {Manual and saccadic reaction times (SRTs) have been used to determine the minimum time required for different types of visual categorizations. Such studies have demonstrated extremely rapid detection of faces within natural scenes, whereas increasingly complex decisions (i.e. levels of processing) require longer processing times. We reasoned that visual categorization speed is not only dependent on the processing level, but is further affected by decisional space constraints. In the context of two different tasks, observers performed choice saccades towards female (gender categorization) or personally familiar (familiarity categorization) faces. Additionally, familiarity categorizations were completed with stimulus sets that differed in the number of individuals presented (3 vs. 7 identities) to investigate the effect of decisional space constraints. We observe an inverse relationship between visual categorization proficiency and decisional space. Observers were most accurate for categorization of gender, which could be achieved in as little as 140 ms. Categorization of highly predictable targets was more error-prone and required an additional ∼100 ms processing time. Our findings add to an increasing body of evidence demonstraing that pre-activation of identity-information can modulate early visual processing in a top-down manner. They also emphasize the importance of considering procedural aspects, as well as terminology when aiming to characterize cognitive processes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Manual and saccadic reaction times (SRTs) have been used to determine the minimum time required for different types of visual categorizations. Such studies have demonstrated extremely rapid detection of faces within natural scenes, whereas increasingly complex decisions (i.e. levels of processing) require longer processing times. We reasoned that visual categorization speed is not only dependent on the processing level, but is further affected by decisional space constraints. In the context of two different tasks, observers performed choice saccades towards female (gender categorization) or personally familiar (familiarity categorization) faces. Additionally, familiarity categorizations were completed with stimulus sets that differed in the number of individuals presented (3 vs. 7 identities) to investigate the effect of decisional space constraints. We observe an inverse relationship between visual categorization proficiency and decisional space. Observers were most accurate for categorization of gender, which could be achieved in as little as 140 ms. Categorization of highly predictable targets was more error-prone and required an additional ∼100 ms processing time. Our findings add to an increasing body of evidence demonstraing that pre-activation of identity-information can modulate early visual processing in a top-down manner. They also emphasize the importance of considering procedural aspects, as well as terminology when aiming to characterize cognitive processes. |
Rajkumar Nallour Raveendran; William R Bobier; Benjamin Thompson Binocular vision and fixational eye movements Journal Article Journal of Vision, 19 (4), pp. 1–15, 2019. @article{Raveendran2019, title = {Binocular vision and fixational eye movements}, author = {Rajkumar Nallour Raveendran and William R Bobier and Benjamin Thompson}, doi = {10.1167/19.4.9}, year = {2019}, date = {2019-01-01}, journal = {Journal of Vision}, volume = {19}, number = {4}, pages = {1--15}, abstract = {The aim of this study was to assess the relationship between binocular vision and fixation stability (FS). Across three experiments, we investigated (a) whether fixation was more stable during binocular versus monocular viewing across a range of stimulus contrasts in normal observers (n = 11), (b) whether binocular rivalry affected FS in normal observers (n = 14), and (c) whether FS was affected by interocular contrast differences in normal observers (n=8) and patients with anisometropic amblyopia (n=5). FS was quantified using global bivariate contour ellipse area, and microsaccades were detected using an unsupervised cluster-detection method. In normal observers, binocular viewing showed more stable fixation at all stimulus contrasts, and binocular rivalry did not affect FS. When interocular contrast was manipulated under dichoptic viewing conditions, normal observers exhibited less stable fixation for an eye that viewed 0% contrast (no fixation target). In anisometropic amblyopia, fixation was less stable in both eyes when the fellow eye viewed at 0% contrast. No effects were observed at other interocular contrast differences. Overall, binocular FS was impaired in both eyes in anisometropic amblyopia compared to normal observers. We conclude that binocular vision influences FS in normal observers but in an all-or-nothing fashion, whereby the presence or absence of a binocular target is important rather than the relative contrast of the targets in each eye. In anisometropic amblyopia, the fellow eye appears to control FS of both eyes under dichoptic viewing conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this study was to assess the relationship between binocular vision and fixation stability (FS). Across three experiments, we investigated (a) whether fixation was more stable during binocular versus monocular viewing across a range of stimulus contrasts in normal observers (n = 11), (b) whether binocular rivalry affected FS in normal observers (n = 14), and (c) whether FS was affected by interocular contrast differences in normal observers (n=8) and patients with anisometropic amblyopia (n=5). FS was quantified using global bivariate contour ellipse area, and microsaccades were detected using an unsupervised cluster-detection method. In normal observers, binocular viewing showed more stable fixation at all stimulus contrasts, and binocular rivalry did not affect FS. When interocular contrast was manipulated under dichoptic viewing conditions, normal observers exhibited less stable fixation for an eye that viewed 0% contrast (no fixation target). In anisometropic amblyopia, fixation was less stable in both eyes when the fellow eye viewed at 0% contrast. No effects were observed at other interocular contrast differences. Overall, binocular FS was impaired in both eyes in anisometropic amblyopia compared to normal observers. We conclude that binocular vision influences FS in normal observers but in an all-or-nothing fashion, whereby the presence or absence of a binocular target is important rather than the relative contrast of the targets in each eye. In anisometropic amblyopia, the fellow eye appears to control FS of both eyes under dichoptic viewing conditions. |
Daniele Re; Maya Inbar; Craig G Richter; Ayelet N Landau Feature-based attention samples stimuli rhythmically Journal Article Current Biology, 29 , pp. 693–699, 2019. @article{Re2019d, title = {Feature-based attention samples stimuli rhythmically}, author = {Daniele Re and Maya Inbar and Craig G Richter and Ayelet N Landau}, doi = {10.1016/j.cub.2019.01.010}, year = {2019}, date = {2019-01-01}, journal = {Current Biology}, volume = {29}, pages = {693--699}, abstract = {Attention supports the allocation of resources to relevant locations and objects in a scene. Under most conditions, several stimuli compete for neural representation. Attention biases neural representation toward the response associated with the attended object [1, 2]. Therefore, an attended stimulus enjoys a neural response that resembles the response to that stimulus in isolation. Factors that determine and generate attentional bias have been researched, ranging from endogenously controlled processes to exogenous capture of attention [1–4]. Recent studies investigate the temporal structure governing attention. When participants monitor a single location, visual-target detection depends on the phase of an ~8-Hz brain rhythm [5, 6]. When two locations are monitored, performance fluctuates at 4 Hz for each location [7, 8]. The hypothesis is that 4-Hz sampling for two locations may reflect a common sampler that operates at 8 Hz globally, which is divided between relevant locations [5–7, 9]. The present study targets two properties of this phenomenon, called rhythmic-attentional sampling: first, sampling is typically described for selection over different locations. We examined whether rhythmic sampling is limited to selection over space or whether it extends to feature-based attention. Second, we examined whether sampling at 4 Hz results from the division of an 8-Hz rhythm over two objects. We found that two overlapping objects defined by features are sampled at ~4 Hz per object. In addition, performance on a single object fluctuated at 8 Hz. Rhythmic sampling of features did not result from temporal structure in eye movements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Attention supports the allocation of resources to relevant locations and objects in a scene. Under most conditions, several stimuli compete for neural representation. Attention biases neural representation toward the response associated with the attended object [1, 2]. Therefore, an attended stimulus enjoys a neural response that resembles the response to that stimulus in isolation. Factors that determine and generate attentional bias have been researched, ranging from endogenously controlled processes to exogenous capture of attention [1–4]. Recent studies investigate the temporal structure governing attention. When participants monitor a single location, visual-target detection depends on the phase of an ~8-Hz brain rhythm [5, 6]. When two locations are monitored, performance fluctuates at 4 Hz for each location [7, 8]. The hypothesis is that 4-Hz sampling for two locations may reflect a common sampler that operates at 8 Hz globally, which is divided between relevant locations [5–7, 9]. The present study targets two properties of this phenomenon, called rhythmic-attentional sampling: first, sampling is typically described for selection over different locations. We examined whether rhythmic sampling is limited to selection over space or whether it extends to feature-based attention. Second, we examined whether sampling at 4 Hz results from the division of an 8-Hz rhythm over two objects. We found that two overlapping objects defined by features are sampled at ~4 Hz per object. In addition, performance on a single object fluctuated at 8 Hz. Rhythmic sampling of features did not result from temporal structure in eye movements. |
David Nicholas Top; Steven G Luke; Kevin G Stephenson; Mikle South Psychophysiological arousal and auditory sensitivity in a cross-clinical sample of autistic and non-autistic anxious adults Journal Article Frontiers in Psychiatry, 9 , pp. 1–12, 2019. @article{Top2019, title = {Psychophysiological arousal and auditory sensitivity in a cross-clinical sample of autistic and non-autistic anxious adults}, author = {David Nicholas Top and Steven G Luke and Kevin G Stephenson and Mikle South}, doi = {10.3389/fpsyt.2018.00783}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Psychiatry}, volume = {9}, pages = {1--12}, abstract = {Many autistic people report overwhelming sensory experiences and also elevated levels of anxiety. Understanding how these experiences are linked to each other can contribute to improved support and intervention for reducing sensory overload and anxiety. This study included 95 young adult participants including autistic adults, non-autistic adults reporting to a psychotherapy clinic with high levels of anxiety, and neurotypical adults with no psychiatric concerns. We measured pupil size using including a baseline task with no auditory stimulus followed by two blocks of simple auditory habituation. In a subset of 80 participants we also measured self-report levels of sensory processing, anxious apprehension, and intolerance of uncertainty. The autism group showed atypical sensory processing on all four measured domains of the Adolescent and Adult Sensory Profile including sensory sensitivity, sensory seeking, sensory avoidance, and low registration subscales. Dimensional analyses across all participants showed significant positive correlations between sensory sensitivity, sensory seeking, and sensory avoidance domains with scores from the Intolerance of Uncertainty Scale-Short Form and Penn State Worry Questionnaire. The autism group showed significantly larger pupil size than other groups at baseline, before any auditory stimulation. There were no group differences in the rate of auditory habituation, nonetheless the overall, absolute larger pupil size remained in the autism group throughout the experiment. We suggest that this and other findings could indicate chronic hyperarousal in many autistic people. Treatment for anxiety in autism should be informed by knowledge of unique aspects of anxiety in autism and consider the role of sensory experience and everyday psychophysiological arousal.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Many autistic people report overwhelming sensory experiences and also elevated levels of anxiety. Understanding how these experiences are linked to each other can contribute to improved support and intervention for reducing sensory overload and anxiety. This study included 95 young adult participants including autistic adults, non-autistic adults reporting to a psychotherapy clinic with high levels of anxiety, and neurotypical adults with no psychiatric concerns. We measured pupil size using including a baseline task with no auditory stimulus followed by two blocks of simple auditory habituation. In a subset of 80 participants we also measured self-report levels of sensory processing, anxious apprehension, and intolerance of uncertainty. The autism group showed atypical sensory processing on all four measured domains of the Adolescent and Adult Sensory Profile including sensory sensitivity, sensory seeking, sensory avoidance, and low registration subscales. Dimensional analyses across all participants showed significant positive correlations between sensory sensitivity, sensory seeking, and sensory avoidance domains with scores from the Intolerance of Uncertainty Scale-Short Form and Penn State Worry Questionnaire. The autism group showed significantly larger pupil size than other groups at baseline, before any auditory stimulation. There were no group differences in the rate of auditory habituation, nonetheless the overall, absolute larger pupil size remained in the autism group throughout the experiment. We suggest that this and other findings could indicate chronic hyperarousal in many autistic people. Treatment for anxiety in autism should be informed by knowledge of unique aspects of anxiety in autism and consider the role of sensory experience and everyday psychophysiological arousal. |
J M Traynor; A Gough; E Duku; D I Shore; G B C Hall Eye tracking effort expenditure and autonomic arousal to social and circumscribed interest stimuli in Autism Spectrum Disorder Journal Article Journal of Autism and Developmental Disorders, 49 , pp. 1988–2002, 2019. @article{Traynor2019, title = {Eye tracking effort expenditure and autonomic arousal to social and circumscribed interest stimuli in Autism Spectrum Disorder}, author = {J M Traynor and A Gough and E Duku and D I Shore and G B C Hall}, doi = {10.1007/s10803-018-03877-y}, year = {2019}, date = {2019-01-01}, journal = {Journal of Autism and Developmental Disorders}, volume = {49}, pages = {1988--2002}, abstract = {The social communicative deficits and repetitive behaviours seen in Autism Spectrum Disorder (ASD) may be affected by altered stimulus salience and reward attribution. The present study used eye tracking and a behavioural measure to index effort expenditure, arousal, and attention, during viewing of images depicting social scenes and subject-specific circumscribed interests in a group of 10 adults with ASD (mean age 25.4 years) and 19 typically-developing controls (mean age 20.7 years) Split-plot and one-way repeated measures ANOVAs were used to explore results. A significant difference between the ASD and control group was found in the amount of effort expended to view social and circumscribed images. The ASD group also displayed significant differences in pupillary response to social and circumscribed images, indicative of changes in autonomic arousal. Overall, the results support the social motivation hypothesis in ASD (Chevallier et al., Trends Cogn Sci 16(4):231-239, 2012) and suggest a role for autonomic arousal in the ASD symptom dyad.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The social communicative deficits and repetitive behaviours seen in Autism Spectrum Disorder (ASD) may be affected by altered stimulus salience and reward attribution. The present study used eye tracking and a behavioural measure to index effort expenditure, arousal, and attention, during viewing of images depicting social scenes and subject-specific circumscribed interests in a group of 10 adults with ASD (mean age 25.4 years) and 19 typically-developing controls (mean age 20.7 years) Split-plot and one-way repeated measures ANOVAs were used to explore results. A significant difference between the ASD and control group was found in the amount of effort expended to view social and circumscribed images. The ASD group also displayed significant differences in pupillary response to social and circumscribed images, indicative of changes in autonomic arousal. Overall, the results support the social motivation hypothesis in ASD (Chevallier et al., Trends Cogn Sci 16(4):231-239, 2012) and suggest a role for autonomic arousal in the ASD symptom dyad. |
Sabrina E Twilhaar; Jorrit F de Kieviet; Catharina E Bergwerff; Martijn J J Finken; Ruurd M van Elburg; Jaap Oosterlaan Social adjustment in adolescents born very preterm: Evidence for a cognitive basis of social problems Journal Article The Journal of Pediatrics, 213 , pp. 66–73, 2019. @article{Twilhaar2019a, title = {Social adjustment in adolescents born very preterm: Evidence for a cognitive basis of social problems}, author = {Sabrina E Twilhaar and Jorrit F de Kieviet and Catharina E Bergwerff and Martijn J J Finken and Ruurd M van Elburg and Jaap Oosterlaan}, doi = {10.1016/j.jpeds.2019.06.045}, year = {2019}, date = {2019-01-01}, journal = {The Journal of Pediatrics}, volume = {213}, pages = {66--73}, publisher = {Elsevier Inc}, abstract = {Objective: To increase the understanding of social adjustment and autism spectrum disorder symptoms in adolescents born very preterm by studying the role of emotion recognition and cognitive control processes in the relation between very preterm birth and social adjustment. Study design: A Dutch cohort of 61 very preterm and 61 full-term adolescents aged 13 years participated. Social adjustment was rated by parents, teachers, and adolescents and autism spectrum disorder symptoms by parents. Emotion recognition was assessed with a computerized task including pictures of child faces expressing anger, fear, sadness, and happiness with varying intensity. Cognitive control was assessed using a visuospatial span, antisaccade, and sustained attention to response task. Performance measures derived from these tasks served as indicators of a latent cognitive control construct, which was tested using confirmatory factor analysis. Mediation analyses were conducted with emotion recognition and cognitive control as mediators of the relation between very preterm birth and social problems. Results: Very preterm adolescents showed more parent- and teacher-rated social problems and increased autism spectrum disorder symptomatology than controls. No difference in self-reported social problems was observed. Moreover, very preterm adolescents showed deficits in emotion recognition and cognitive control compared with full-term adolescents. The relation between very preterm birth and parent-rated social problems was significantly mediated by cognitive control but not by emotion recognition. Very preterm birth was associated with a 0.67-SD increase in parent-rated social problems through its negative effect on cognitive control. Conclusions: The present findings provide strong evidence for a central role of impaired cognitive control in the social problems of adolescents born very preterm.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: To increase the understanding of social adjustment and autism spectrum disorder symptoms in adolescents born very preterm by studying the role of emotion recognition and cognitive control processes in the relation between very preterm birth and social adjustment. Study design: A Dutch cohort of 61 very preterm and 61 full-term adolescents aged 13 years participated. Social adjustment was rated by parents, teachers, and adolescents and autism spectrum disorder symptoms by parents. Emotion recognition was assessed with a computerized task including pictures of child faces expressing anger, fear, sadness, and happiness with varying intensity. Cognitive control was assessed using a visuospatial span, antisaccade, and sustained attention to response task. Performance measures derived from these tasks served as indicators of a latent cognitive control construct, which was tested using confirmatory factor analysis. Mediation analyses were conducted with emotion recognition and cognitive control as mediators of the relation between very preterm birth and social problems. Results: Very preterm adolescents showed more parent- and teacher-rated social problems and increased autism spectrum disorder symptomatology than controls. No difference in self-reported social problems was observed. Moreover, very preterm adolescents showed deficits in emotion recognition and cognitive control compared with full-term adolescents. The relation between very preterm birth and parent-rated social problems was significantly mediated by cognitive control but not by emotion recognition. Very preterm birth was associated with a 0.67-SD increase in parent-rated social problems through its negative effect on cognitive control. Conclusions: The present findings provide strong evidence for a central role of impaired cognitive control in the social problems of adolescents born very preterm. |
Avinash R Vaidya; Lesley K Fellows Ventromedial frontal lobe damage affects interpretation, not exploration, of emotional facial expressions Journal Article Cortex, 113 , pp. 312–328, 2019. @article{Vaidya2019, title = {Ventromedial frontal lobe damage affects interpretation, not exploration, of emotional facial expressions}, author = {Avinash R Vaidya and Lesley K Fellows}, doi = {10.1016/j.cortex.2018.12.013}, year = {2019}, date = {2019-01-01}, journal = {Cortex}, volume = {113}, pages = {312--328}, abstract = {Recognizing and distinguishing the emotional states of those around us is crucial for adaptive social behavior. Previous work has shown that damage to the ventromedial frontal lobe (VMF) impairs recognition of subtle emotional facial expressions and affects fixation patterns to face stimuli. However, whether this relates to deficits in acquiring or interpreting facial expression information remains unclear. We tested 37 patients with frontal lobe damage, including 17 subjects with VMF lesions, in a series of emotion recognition tasks with different gaze manipulations. Subjects were asked to rate neutral, subtle and extreme emotional expressions while freely examining faces, while instructed to look only at the eyes, and in a gaze-contingent condition that required top-down direction of eye movements to reveal the stimulus. People with VMF damage were worse at detecting subtle disgust during free viewing and confused extreme emotional expressions more than healthy controls. However, fixation patterns did not differ systematically between groups during free or gaze-contingent viewing conditions. Moreover, instruction to fixate only the eyes did not improve the performance of VMF damaged subjects. These data argue that VMF is not necessary for normal fixations to emotional face stimuli, and that impairments in emotion recognition after VMF damage do not stem from impaired information gathering, as indexed by patterns of fixation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recognizing and distinguishing the emotional states of those around us is crucial for adaptive social behavior. Previous work has shown that damage to the ventromedial frontal lobe (VMF) impairs recognition of subtle emotional facial expressions and affects fixation patterns to face stimuli. However, whether this relates to deficits in acquiring or interpreting facial expression information remains unclear. We tested 37 patients with frontal lobe damage, including 17 subjects with VMF lesions, in a series of emotion recognition tasks with different gaze manipulations. Subjects were asked to rate neutral, subtle and extreme emotional expressions while freely examining faces, while instructed to look only at the eyes, and in a gaze-contingent condition that required top-down direction of eye movements to reveal the stimulus. People with VMF damage were worse at detecting subtle disgust during free viewing and confused extreme emotional expressions more than healthy controls. However, fixation patterns did not differ systematically between groups during free or gaze-contingent viewing conditions. Moreover, instruction to fixate only the eyes did not improve the performance of VMF damaged subjects. These data argue that VMF is not necessary for normal fixations to emotional face stimuli, and that impairments in emotion recognition after VMF damage do not stem from impaired information gathering, as indexed by patterns of fixation. |
Nils S Van Den Berg; Rients B Huitema; Jacoba M Spikman; Peter Jan Van Laar; Edward H F De Haan A shrunken world–micropsia after a right occipito-parietal ischemic stroke Journal Article Neurocase, 25 (5), pp. 202–208, 2019. @article{VanDenBerg2019a, title = {A shrunken world–micropsia after a right occipito-parietal ischemic stroke}, author = {Nils S {Van Den Berg} and Rients B Huitema and Jacoba M Spikman and Peter Jan {Van Laar} and Edward H F {De Haan}}, doi = {10.1080/13554794.2019.1656751}, year = {2019}, date = {2019-01-01}, journal = {Neurocase}, volume = {25}, number = {5}, pages = {202--208}, publisher = {Routledge}, abstract = {Micropsia is a rare condition in which patients perceive the outside world smaller in size than it actually is. We examined a patient who, after a right occipito-parietal stroke, subjectively reported perceiving everything at seventy percent of the actual size. Using experimental tasks, we confirmed the extent of his micropsia at 70%. Visual half-field tests showed an impaired perception of shape, location and motion in the left visual field. As his micropsia concerns the complete visual field, we suggest that it is caused by a higher-order compensation process in order to reconcile the conflicting information from the two hemifields.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Micropsia is a rare condition in which patients perceive the outside world smaller in size than it actually is. We examined a patient who, after a right occipito-parietal stroke, subjectively reported perceiving everything at seventy percent of the actual size. Using experimental tasks, we confirmed the extent of his micropsia at 70%. Visual half-field tests showed an impaired perception of shape, location and motion in the left visual field. As his micropsia concerns the complete visual field, we suggest that it is caused by a higher-order compensation process in order to reconcile the conflicting information from the two hemifields. |
Stefan Van der Stigchel; Frans S S Leijten; Mariska J Vansteensel; Hendrik Chris Dijkerman; Nick F Ramsey; Zachary V Freudenburg Removal of epileptically compromised tissue in the frontal cortex restores oculomotor selection in the antisaccade task Journal Article Journal of Neuropsychology, 13 (2), pp. 289–304, 2019. @article{VanderStigchel2019, title = {Removal of epileptically compromised tissue in the frontal cortex restores oculomotor selection in the antisaccade task}, author = {Stefan {Van der Stigchel} and Frans S S Leijten and Mariska J Vansteensel and Hendrik Chris Dijkerman and Nick F Ramsey and Zachary V Freudenburg}, doi = {10.1111/jnp.12143}, year = {2019}, date = {2019-01-01}, journal = {Journal of Neuropsychology}, volume = {13}, number = {2}, pages = {289--304}, abstract = {The frontal cortex is heavily involved in oculomotor selection. Here, we investigated the neural correlates of eye movement selection during an antisaccade task in a young epileptic patient in whom the seizure focus included the frontal cortex and affected its function. Before resection surgery, the patient had difficulty in performing correct antisaccades towards the visual field contralateral to the seizure focus. Because the FEF is the only area in the human frontal cortex that is known to have a lateralized oculomotor function in the antisaccade task, this behavioural imbalance between the two visual fields suggests a disruption of FEF functioning by the nearby seizure focus. Electrocorticographic recordings at the seizure focus indeed showed that the seizure focus interfered with correct antisaccade performance. These results were in line with fMRI recordings revealing less task-related frontal activity for the hemisphere of the seizure focus, possibly reflecting diminished top-down engagement of the oculomotor system. Two months after removal of the compromised tissue, the seizures had disappeared, and antisaccade performance was the same for both visual hemifields. We conclude that a seizure focus in the frontal cortex can induce a dysfunction in the selection of eye movements, which is resolved after removal of interfering tissue.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The frontal cortex is heavily involved in oculomotor selection. Here, we investigated the neural correlates of eye movement selection during an antisaccade task in a young epileptic patient in whom the seizure focus included the frontal cortex and affected its function. Before resection surgery, the patient had difficulty in performing correct antisaccades towards the visual field contralateral to the seizure focus. Because the FEF is the only area in the human frontal cortex that is known to have a lateralized oculomotor function in the antisaccade task, this behavioural imbalance between the two visual fields suggests a disruption of FEF functioning by the nearby seizure focus. Electrocorticographic recordings at the seizure focus indeed showed that the seizure focus interfered with correct antisaccade performance. These results were in line with fMRI recordings revealing less task-related frontal activity for the hemisphere of the seizure focus, possibly reflecting diminished top-down engagement of the oculomotor system. Two months after removal of the compromised tissue, the seizures had disappeared, and antisaccade performance was the same for both visual hemifields. We conclude that a seizure focus in the frontal cortex can induce a dysfunction in the selection of eye movements, which is resolved after removal of interfering tissue. |
Rozemarijn S van Kleef; Claudi L H Bockting; Evelien van Valen; André Aleman; Jan Bernard C Marsman; Marie José van Tol BMC Psychiatry, 19 , pp. 1–11, 2019. @article{Kleef2019, title = {Neurocognitive working mechanisms of the prevention of relapse in remitted recurrent depression (NEWPRIDE): Protocol of a randomized controlled neuroimaging trial of preventive cognitive therapy}, author = {Rozemarijn S van Kleef and Claudi L H Bockting and Evelien van Valen and André Aleman and Jan Bernard C Marsman and Marie José van Tol}, doi = {10.1186/s12888-019-2384-0}, year = {2019}, date = {2019-01-01}, journal = {BMC Psychiatry}, volume = {19}, pages = {1--11}, publisher = {BMC Psychiatry}, abstract = {Background: Major Depressive Disorder (MDD) is a psychiatric disorder with a highly recurrent character, making prevention of relapse an important clinical goal. Preventive Cognitive Therapy (PCT) has been proven effective in preventing relapse, though not for every patient. A better understanding of relapse vulnerability and working mechanisms of preventive treatment may inform effective personalized intervention strategies. Neurocognitive models of MDD suggest that abnormalities in prefrontal control over limbic emotion-processing areas during emotional processing and regulation are important in understanding relapse vulnerability. Whether changes in these neurocognitive abnormalities are induced by PCT and thus play an important role in mediating the risk for recurrent depression, is currently unclear. In the Neurocognitive Working Mechanisms of the Prevention of Relapse In Depression (NEWPRIDE) study, we aim to 1) study neurocognitive factors underpinning the vulnerability for relapse, 2) understand the neurocognitive working mechanisms of PCT, 3) predict longitudinal treatment effects based on pre-treatment neurocognitive characteristics, and 4) validate the pupil dilation response as a marker for prefrontal activity, reflecting emotion regulation capacity and therapy success. Methods: In this randomized controlled trial, 75 remitted recurrent MDD (rrMDD) patients will be included. Detailed clinical and cognitive measurements, fMRI scanning and pupillometry will be performed at baseline and three-month follow-up. In the interval, 50 rrMDD patients will be randomized to eight sessions of PCT and 25 rrMDD patients to a waiting list. At baseline, 25 healthy control participants will be additionally included to objectify cross-sectional residual neurocognitive abnormalities in rrMDD. After 18 months, clinical assessments of relapse status are performed to investigate which therapy induced changes predict relapse in the 50 patients allocated to PCT. Discussion: The present trial is the first to study the neurocognitive vulnerability factors underlying relapse and mediating relapse prevention, their value for predicting PCT success and whether pupil dilation acts as a valuable marker in this regard. Ultimately, a deeper understanding of relapse prevention could contribute to the development of better targeted preventive interventions. Trial registration: Trial registration: Netherlands Trial Register, August 18, 2015, trial number NL5219.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Major Depressive Disorder (MDD) is a psychiatric disorder with a highly recurrent character, making prevention of relapse an important clinical goal. Preventive Cognitive Therapy (PCT) has been proven effective in preventing relapse, though not for every patient. A better understanding of relapse vulnerability and working mechanisms of preventive treatment may inform effective personalized intervention strategies. Neurocognitive models of MDD suggest that abnormalities in prefrontal control over limbic emotion-processing areas during emotional processing and regulation are important in understanding relapse vulnerability. Whether changes in these neurocognitive abnormalities are induced by PCT and thus play an important role in mediating the risk for recurrent depression, is currently unclear. In the Neurocognitive Working Mechanisms of the Prevention of Relapse In Depression (NEWPRIDE) study, we aim to 1) study neurocognitive factors underpinning the vulnerability for relapse, 2) understand the neurocognitive working mechanisms of PCT, 3) predict longitudinal treatment effects based on pre-treatment neurocognitive characteristics, and 4) validate the pupil dilation response as a marker for prefrontal activity, reflecting emotion regulation capacity and therapy success. Methods: In this randomized controlled trial, 75 remitted recurrent MDD (rrMDD) patients will be included. Detailed clinical and cognitive measurements, fMRI scanning and pupillometry will be performed at baseline and three-month follow-up. In the interval, 50 rrMDD patients will be randomized to eight sessions of PCT and 25 rrMDD patients to a waiting list. At baseline, 25 healthy control participants will be additionally included to objectify cross-sectional residual neurocognitive abnormalities in rrMDD. After 18 months, clinical assessments of relapse status are performed to investigate which therapy induced changes predict relapse in the 50 patients allocated to PCT. Discussion: The present trial is the first to study the neurocognitive vulnerability factors underlying relapse and mediating relapse prevention, their value for predicting PCT success and whether pupil dilation acts as a valuable marker in this regard. Ultimately, a deeper understanding of relapse prevention could contribute to the development of better targeted preventive interventions. Trial registration: Trial registration: Netherlands Trial Register, August 18, 2015, trial number NL5219. |
Anita E Wagner; Leanne Nagels; Paolo Toffanin; Jane M Opie; Deniz Başkent Individual variations in effort: Assessing pupillometry for the hearing impaired Journal Article Trends in Hearing, 23 , pp. 1–18, 2019. @article{Wagner2019, title = {Individual variations in effort: Assessing pupillometry for the hearing impaired}, author = {Anita E Wagner and Leanne Nagels and Paolo Toffanin and Jane M Opie and Deniz Başkent}, doi = {10.1177/2331216519845596}, year = {2019}, date = {2019-01-01}, journal = {Trends in Hearing}, volume = {23}, pages = {1--18}, abstract = {Assessing effort in speech comprehension for hearing-impaired (HI) listeners is important, as effortful processing of speech can limit their hearing rehabilitation. We examined the measure of pupil dilation in its capacity to accommodate the heterogeneity that is present within clinical populations by studying lexical access in users with sensorineural hearing loss, who perceive speech via cochlear implants (CIs). We compared the pupillary responses of 15 experienced CI users and 14 age-matched normal-hearing (NH) controls during auditory lexical decision. A growth curve analysis was applied to compare the responses between the groups. NH listeners showed a coherent pattern of pupil dilation that reflects the task demands of the experimental manipulation and a homogenous time course of dilation. CI listeners showed more variability in the morphology of pupil dilation curves, potentially reflecting variable sources of effort across individuals. In follow-up analyses, we examined how speech perception, a task that relies on multiple stages of perceptual analyses, poses multiple sources of increased effort for HI listeners, wherefore we might not be measuring the same source of effort for HI as for NH listeners. We argue that interindividual variability among HI listeners can be clinically meaningful in attesting not only the magnitude but also the locus of increased effort. The understanding of individual variations in effort requires experimental paradigms that (a) differentiate the task demands during speech comprehension, (b) capture pupil dilation in its time course per individual listeners, and (c) investigate the range of individual variability present within clinical and NH populations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Assessing effort in speech comprehension for hearing-impaired (HI) listeners is important, as effortful processing of speech can limit their hearing rehabilitation. We examined the measure of pupil dilation in its capacity to accommodate the heterogeneity that is present within clinical populations by studying lexical access in users with sensorineural hearing loss, who perceive speech via cochlear implants (CIs). We compared the pupillary responses of 15 experienced CI users and 14 age-matched normal-hearing (NH) controls during auditory lexical decision. A growth curve analysis was applied to compare the responses between the groups. NH listeners showed a coherent pattern of pupil dilation that reflects the task demands of the experimental manipulation and a homogenous time course of dilation. CI listeners showed more variability in the morphology of pupil dilation curves, potentially reflecting variable sources of effort across individuals. In follow-up analyses, we examined how speech perception, a task that relies on multiple stages of perceptual analyses, poses multiple sources of increased effort for HI listeners, wherefore we might not be measuring the same source of effort for HI as for NH listeners. We argue that interindividual variability among HI listeners can be clinically meaningful in attesting not only the magnitude but also the locus of increased effort. The understanding of individual variations in effort requires experimental paradigms that (a) differentiate the task demands during speech comprehension, (b) capture pupil dilation in its time course per individual listeners, and (c) investigate the range of individual variability present within clinical and NH populations. |
Shuo Wang; Nand Chandravadia; Adam N Mamelak; Ueli Rutishauser Simultaneous eye tracking and single-neuron recordings in human epilepsy patients Journal Article Journal of Visualized Experiments, (148), pp. 1–7, 2019. @article{Wang2019i, title = {Simultaneous eye tracking and single-neuron recordings in human epilepsy patients}, author = {Shuo Wang and Nand Chandravadia and Adam N Mamelak and Ueli Rutishauser}, doi = {10.3791/59117}, year = {2019}, date = {2019-01-01}, journal = {Journal of Visualized Experiments}, number = {148}, pages = {1--7}, abstract = {Intracranial recordings from patients with intractable epilepsy provide a unique opportunity to study the activity of individual human neurons during active behavior. An important tool for quantifying behavior is eye tracking, which is an indispensable tool for studying visual attention. However, eye tracking is challenging to use concurrently with invasive electrophysiology and this approach has consequently been little used. Here, we present a proven experimental protocol to conduct single-neuron recordings with simultaneous eye tracking in humans. We describe how the systems are connected and the optimal settings to record neurons and eye movements. To illustrate the utility of this method, we summarize results that were made possible by this setup. This data shows how using eye tracking in a memory-guided visual search task allowed us to describe a new class of neurons called target neurons, whose response was reflective of top-down attention to the current search target. Lastly, we discuss the significance and solutions to potential problems of this setup. Together, our protocol and results suggest that single-neuron recordings with simultaneous eye tracking in humans are an effective method to study human brain function. It provides a key missing link between animal neurophysiology and human cognitive neuroscience.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Intracranial recordings from patients with intractable epilepsy provide a unique opportunity to study the activity of individual human neurons during active behavior. An important tool for quantifying behavior is eye tracking, which is an indispensable tool for studying visual attention. However, eye tracking is challenging to use concurrently with invasive electrophysiology and this approach has consequently been little used. Here, we present a proven experimental protocol to conduct single-neuron recordings with simultaneous eye tracking in humans. We describe how the systems are connected and the optimal settings to record neurons and eye movements. To illustrate the utility of this method, we summarize results that were made possible by this setup. This data shows how using eye tracking in a memory-guided visual search task allowed us to describe a new class of neurons called target neurons, whose response was reflective of top-down attention to the current search target. Lastly, we discuss the significance and solutions to potential problems of this setup. Together, our protocol and results suggest that single-neuron recordings with simultaneous eye tracking in humans are an effective method to study human brain function. It provides a key missing link between animal neurophysiology and human cognitive neuroscience. |
Shuo Wang; Adam N Mamelak; Ralph Adolphs; Ueli Rutishauser Abstract goal representation in visual search by neurons in the human pre-supplementary motor area Journal Article Brain, 142 (11), pp. 3530–3549, 2019. @article{Wang2019j, title = {Abstract goal representation in visual search by neurons in the human pre-supplementary motor area}, author = {Shuo Wang and Adam N Mamelak and Ralph Adolphs and Ueli Rutishauser}, doi = {10.1093/brain/awz279}, year = {2019}, date = {2019-01-01}, journal = {Brain}, volume = {142}, number = {11}, pages = {3530--3549}, abstract = {The medial frontal cortex is important for goal-directed behaviours such as visual search. The pre-supplementary motor area (pre-SMA) plays a critical role in linking higher-level goals to actions, but little is known about the responses of individual cells in this area in humans. Pre-SMA dysfunction is thought to be a critical factor in the cognitive deficits that are observed in diseases such as Parkinson's disease and schizophrenia, making it important to develop a better mechanistic understanding of the pre-SMA's role in cognition. We simultaneously recorded single neurons in the human pre-SMA and eye movements while subjects performed goal-directed visual search tasks. We characterized two groups of neurons in the pre-SMA. First, 40% of neurons changed their firing rate whenever a fixation landed on the search target. These neurons responded to targets in an abstract manner across several conditions and tasks. Responses were invariant to motor output (i.e. button press or not), and to different ways of defining the search target (by instruction or pop-out). Second, ∼50% of neurons changed their response as a function of fixation order. Together, our results show that human pre-SMA neurons carry abstract signals during visual search that indicate whether a goal was reached in an action- and cue-independent manner. This suggests that the pre-SMA contributes to goal-directed behaviour by flexibly signalling goal detection and time elapsed since start of the search, and this process occurs regardless of task. These observations provide insights into how pre-SMA dysfunction might impact cognitive function.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The medial frontal cortex is important for goal-directed behaviours such as visual search. The pre-supplementary motor area (pre-SMA) plays a critical role in linking higher-level goals to actions, but little is known about the responses of individual cells in this area in humans. Pre-SMA dysfunction is thought to be a critical factor in the cognitive deficits that are observed in diseases such as Parkinson's disease and schizophrenia, making it important to develop a better mechanistic understanding of the pre-SMA's role in cognition. We simultaneously recorded single neurons in the human pre-SMA and eye movements while subjects performed goal-directed visual search tasks. We characterized two groups of neurons in the pre-SMA. First, 40% of neurons changed their firing rate whenever a fixation landed on the search target. These neurons responded to targets in an abstract manner across several conditions and tasks. Responses were invariant to motor output (i.e. button press or not), and to different ways of defining the search target (by instruction or pop-out). Second, ∼50% of neurons changed their response as a function of fixation order. Together, our results show that human pre-SMA neurons carry abstract signals during visual search that indicate whether a goal was reached in an action- and cue-independent manner. This suggests that the pre-SMA contributes to goal-directed behaviour by flexibly signalling goal detection and time elapsed since start of the search, and this process occurs regardless of task. These observations provide insights into how pre-SMA dysfunction might impact cognitive function. |
Shannon E Weissman; Alexander Lithopoulos; Jennifer R Tomasone; Amy E Latimer-Cheung Exploring gaze behaviors toward images of physically active individuals with a physical disability Journal Article Psychology of Sport and Exercise, 45 , pp. 1–9, 2019. @article{Weissman2019, title = {Exploring gaze behaviors toward images of physically active individuals with a physical disability}, author = {Shannon E Weissman and Alexander Lithopoulos and Jennifer R Tomasone and Amy E Latimer-Cheung}, doi = {10.1016/j.psychsport.2019.05.002}, year = {2019}, date = {2019-01-01}, journal = {Psychology of Sport and Exercise}, volume = {45}, pages = {1--9}, publisher = {Elsevier}, abstract = {Objectives: The study had two main objectives: (1) to characterize able-bodied adults' gaze behaviors when viewing images of people with and without physical disabilities and in turn, (2) to examine whether portraying a person with a disability as physically active (shown participating in physical activity [i.e, sport/exercise]) versus inactive (not engaging in physical activity) affects gaze behavior. The study also had an exploratory objective: to examine the specific physical traits able-bodied adults gaze at when viewing active versus inactive people with physical disabilities. Design: Within-subjects cross-sectional design consisting of 63 men and women without self-reported disabilities (Mage = 21.22 ± 2.52 years). Method: Participants viewed a series of 48 images for 5 s each. Images featured an able-bodied or disabled, active or inactive model. Eye movements were recorded while viewing each image. Differences in gaze behavior were assessed using a series of repeated measures multivariate factorial ANOVAs with Bonferroni-corrected pairwise comparisons to decompose interactions. Results: Participants gazed significantly more at images of individuals with physical disabilities than images of able-bodied individuals. Furthermore, participants gazed significantly less at images portraying active versus inactive individuals with physical disabilities. A greater proportion of gaze behavior was directed toward the assistive device when the person with a disability was portrayed as active versus inactive. Conclusions: This study demonstrated that able-bodied adults may gaze less at images of individuals with physical disabilities who are depicted as active versus inactive. Further research is needed to examine how these gaze patterns translate to live social situations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objectives: The study had two main objectives: (1) to characterize able-bodied adults' gaze behaviors when viewing images of people with and without physical disabilities and in turn, (2) to examine whether portraying a person with a disability as physically active (shown participating in physical activity [i.e, sport/exercise]) versus inactive (not engaging in physical activity) affects gaze behavior. The study also had an exploratory objective: to examine the specific physical traits able-bodied adults gaze at when viewing active versus inactive people with physical disabilities. Design: Within-subjects cross-sectional design consisting of 63 men and women without self-reported disabilities (Mage = 21.22 ± 2.52 years). Method: Participants viewed a series of 48 images for 5 s each. Images featured an able-bodied or disabled, active or inactive model. Eye movements were recorded while viewing each image. Differences in gaze behavior were assessed using a series of repeated measures multivariate factorial ANOVAs with Bonferroni-corrected pairwise comparisons to decompose interactions. Results: Participants gazed significantly more at images of individuals with physical disabilities than images of able-bodied individuals. Furthermore, participants gazed significantly less at images portraying active versus inactive individuals with physical disabilities. A greater proportion of gaze behavior was directed toward the assistive device when the person with a disability was portrayed as active versus inactive. Conclusions: This study demonstrated that able-bodied adults may gaze less at images of individuals with physical disabilities who are depicted as active versus inactive. Further research is needed to examine how these gaze patterns translate to live social situations. |
Jessica Werthmann; Mima Simic; Anna Konstantellou; Phoebe Mansfield; Daniela Mercado; Welmoed van Ens; Ulrike Schmidt Same, same but different: Attention bias for food cues in adults and adolescents with anorexia nervosa Journal Article International Journal of Eating Disorders, 52 (6), pp. 681–690, 2019. @article{Werthmann2019, title = {Same, same but different: Attention bias for food cues in adults and adolescents with anorexia nervosa}, author = {Jessica Werthmann and Mima Simic and Anna Konstantellou and Phoebe Mansfield and Daniela Mercado and Welmoed van Ens and Ulrike Schmidt}, doi = {10.1002/eat.23064}, year = {2019}, date = {2019-01-01}, journal = {International Journal of Eating Disorders}, volume = {52}, number = {6}, pages = {681--690}, abstract = {Objective: Attention processing for food may be biased in people with Anorexia Nervosa (AN). However, previous studies have had inconsistent results. This is likely to be due to indirect assessment of attention, which does not inform on the underlying attention processes, and/or the heterogeneity of participants across studies, testing either adults or adolescents with AN, that is, people at very different developmental and illness stages. Method: Eye-tracking was employed as a direct assessment of attention during a visual probe task with food versus non-food pictures. Attention bias for food was measured in 39 adults and 34 adolescents with AN and in 53 adults and 31 adolescents without AN. Results: All participants had a direction bias for food, specifically for high-calorie food. However, adults with AN subsequently avoided maintaining attention on food versus non-food cues, compared to adults without AN. Adolescents with or without AN demonstrated increased attention maintenance on food versus non-food cues, and, contrary to our hypothesis, did not differ in their attention bias for food cues. Accordingly, adults with AN differed significantly from adolescents with AN in attention maintenance for food cues: while adolescents with AN showed significantly increased attention maintenance on food stimuli, adults avoided maintaining attention on food cues. Discussion: Adults with AN may apply attention strategies to facilitate restrictive eating. This strategy is absent in adolescents with AN. This difference in food-related attention bias between adolescents and adults with AN suggests that attention biases develop over time as the illness progresses.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: Attention processing for food may be biased in people with Anorexia Nervosa (AN). However, previous studies have had inconsistent results. This is likely to be due to indirect assessment of attention, which does not inform on the underlying attention processes, and/or the heterogeneity of participants across studies, testing either adults or adolescents with AN, that is, people at very different developmental and illness stages. Method: Eye-tracking was employed as a direct assessment of attention during a visual probe task with food versus non-food pictures. Attention bias for food was measured in 39 adults and 34 adolescents with AN and in 53 adults and 31 adolescents without AN. Results: All participants had a direction bias for food, specifically for high-calorie food. However, adults with AN subsequently avoided maintaining attention on food versus non-food cues, compared to adults without AN. Adolescents with or without AN demonstrated increased attention maintenance on food versus non-food cues, and, contrary to our hypothesis, did not differ in their attention bias for food cues. Accordingly, adults with AN differed significantly from adolescents with AN in attention maintenance for food cues: while adolescents with AN showed significantly increased attention maintenance on food stimuli, adults avoided maintaining attention on food cues. Discussion: Adults with AN may apply attention strategies to facilitate restrictive eating. This strategy is absent in adolescents with AN. This difference in food-related attention bias between adolescents and adults with AN suggests that attention biases develop over time as the illness progresses. |
Anne M Wienholz Amy Lieberman Semantic processing of adjectives and nouns in American Sign Language: Effects of reference ambiguity and word order across development Journal Article Journal of Cultural Cognitive Science, pp. 1–18, 2019. @article{WienholzAmyLieberman2019, title = {Semantic processing of adjectives and nouns in American Sign Language: Effects of reference ambiguity and word order across development}, author = {Anne M {Wienholz Amy Lieberman}}, doi = {10.1007/s41809-019-00024-6}, year = {2019}, date = {2019-01-01}, journal = {Journal of Cultural Cognitive Science}, pages = {1--18}, abstract = {When processing spoken language sentences , listeners continuously make and revise predictions about the upcoming linguistic signal. In contrast, during comprehension of American Sign Language (ASL), signers must simultaneously attend to the unfolding linguistic signal and the surrounding scene via the visual modality. This may affect how signers activate potential lexical candidates and allocate visual attention as a sentence unfolds. To determine how signers resolve referential ambiguity during real-time comprehension of ASL adjectives and nouns, we presented deaf adults (n = 18, 19-61 years) and deaf children (n = 20, 4-8 years) with videos of ASL sentences in a visual world paradigm. Sentences had either an adjective-noun (e.g., ''SEE YELLOW WHAT? FLOWER'') or a noun-adjective (e.g., ''SEE FLOWER WHICH? YELLOW'') structure. The degree of ambiguity in the visual scene was manipulated at the adjective and noun levels (e.g., including one or more yellow items and one or more flowers in the visual array). We investigated effects of ambiguity and word order on target looking at early and late points in the sentence. Analysis revealed that adults and children made anticipatory looks to a target when it could be identified early in the sentence. Further, signers looked more to potential lexical candidates than to unrelated competitors in the early window, and more to matched than unrelated competitors in the late window. Chil-dren's gaze patterns largely aligned with those of adults, although they made fewer anticipatory fixations to the target in the early window and were more susceptible to competitors in the late window. Together, these findings suggest that signers allocate referential attention strategically based on the amount and type of ambiguity at different points in the sentence when processing adjectives and nouns in ASL.}, keywords = {}, pubstate = {published}, tppubtype = {article} } When processing spoken language sentences , listeners continuously make and revise predictions about the upcoming linguistic signal. In contrast, during comprehension of American Sign Language (ASL), signers must simultaneously attend to the unfolding linguistic signal and the surrounding scene via the visual modality. This may affect how signers activate potential lexical candidates and allocate visual attention as a sentence unfolds. To determine how signers resolve referential ambiguity during real-time comprehension of ASL adjectives and nouns, we presented deaf adults (n = 18, 19-61 years) and deaf children (n = 20, 4-8 years) with videos of ASL sentences in a visual world paradigm. Sentences had either an adjective-noun (e.g., ''SEE YELLOW WHAT? FLOWER'') or a noun-adjective (e.g., ''SEE FLOWER WHICH? YELLOW'') structure. The degree of ambiguity in the visual scene was manipulated at the adjective and noun levels (e.g., including one or more yellow items and one or more flowers in the visual array). We investigated effects of ambiguity and word order on target looking at early and late points in the sentence. Analysis revealed that adults and children made anticipatory looks to a target when it could be identified early in the sentence. Further, signers looked more to potential lexical candidates than to unrelated competitors in the early window, and more to matched than unrelated competitors in the late window. Chil-dren's gaze patterns largely aligned with those of adults, although they made fewer anticipatory fixations to the target in the early window and were more susceptible to competitors in the late window. Together, these findings suggest that signers allocate referential attention strategically based on the amount and type of ambiguity at different points in the sentence when processing adjectives and nouns in ASL. |
Thomas D W Wilcockson; Emmanuel M Pothos; Andrew C Parrott Substance usage intention does not affect attentional bias: Implications from Ecstasy/MDMA users and alcohol drinkers Journal Article Addictive Behaviors, 88 , pp. 175–181, 2019. @article{Wilcockson2019b, title = {Substance usage intention does not affect attentional bias: Implications from Ecstasy/MDMA users and alcohol drinkers}, author = {Thomas D W Wilcockson and Emmanuel M Pothos and Andrew C Parrott}, doi = {10.1016/j.addbeh.2018.09.001}, year = {2019}, date = {2019-01-01}, journal = {Addictive Behaviors}, volume = {88}, pages = {175--181}, publisher = {Elsevier}, abstract = {Background: An attentional bias towards substance-related stimuli has been demonstrated with alcohol drinkers and many other types of substance user. There is evidence to suggest that the strength of an attentional bias may vary as a result of context (or use intention), especially within Ecstasy/MDMA users. Objective: Our aim was to empirically investigate attentional biases by observing the affect that use intention plays in recreational MDMA users and compare the findings with that of alcohol users. Method: Regular alcohol drinkers were compared with MDMA users. Performance was assessed for each group separately using two versions of an eye-tracking attentional bias task with pairs of matched neutral, and alcohol or MDMA-related visual stimuli. Dwell time was recorded for alcohol or MDMA. Participants were tested twice, when intending and not intending to use MDMA or alcohol. Note, participants in the alcohol group did not complete any tasks which involved MDMA-related stimuli and vice versa. Results: Significant attentional biases were found with both MDMA and alcohol users for respective substance-related stimuli, but not control stimuli. Critically, use intention did not affect attentional biases. Attentional biases were demonstrated with both MDMA users and alcohol drinkers when usage was and was not intended. Conclusions: These findings demonstrate the robust nature of attentional biases i.e. once an attentional bias has developed, it is not readily affected by intention.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: An attentional bias towards substance-related stimuli has been demonstrated with alcohol drinkers and many other types of substance user. There is evidence to suggest that the strength of an attentional bias may vary as a result of context (or use intention), especially within Ecstasy/MDMA users. Objective: Our aim was to empirically investigate attentional biases by observing the affect that use intention plays in recreational MDMA users and compare the findings with that of alcohol users. Method: Regular alcohol drinkers were compared with MDMA users. Performance was assessed for each group separately using two versions of an eye-tracking attentional bias task with pairs of matched neutral, and alcohol or MDMA-related visual stimuli. Dwell time was recorded for alcohol or MDMA. Participants were tested twice, when intending and not intending to use MDMA or alcohol. Note, participants in the alcohol group did not complete any tasks which involved MDMA-related stimuli and vice versa. Results: Significant attentional biases were found with both MDMA and alcohol users for respective substance-related stimuli, but not control stimuli. Critically, use intention did not affect attentional biases. Attentional biases were demonstrated with both MDMA users and alcohol drinkers when usage was and was not intended. Conclusions: These findings demonstrate the robust nature of attentional biases i.e. once an attentional bias has developed, it is not readily affected by intention. |
Beier Yao; Sebastiaan F W Neggers; Martin X Rolfs; X Lara Rösler; Ilse A Thompson; Helene J Hopman; Livon Ghermezi; René S Kahn; Katharine N Thakkar Structural thalamofrontal hypoconnectivity is related to oculomotor corollary discharge dysfunction in schizophrenia Journal Article The Journal of Neuroscience, 39 (11), pp. 2102–2113, 2019. @article{Yao2019, title = {Structural thalamofrontal hypoconnectivity is related to oculomotor corollary discharge dysfunction in schizophrenia}, author = {Beier Yao and Sebastiaan F W Neggers and Martin X Rolfs and X {Lara Rösler} and Ilse A Thompson and Helene J Hopman and Livon Ghermezi and René S Kahn and Katharine N Thakkar}, doi = {10.1523/JNEUROSCI.1473-18.2019}, year = {2019}, date = {2019-01-01}, journal = {The Journal of Neuroscience}, volume = {39}, number = {11}, pages = {2102--2113}, abstract = {By predicting sensory consequences of actions, humans can distinguish self-generated sensory inputs from those that are elicited externally. This is one mechanism by which we achieve a subjective sense of agency over our actions. Corollary discharge (CD) signals-"copies" of motor signals sent to sensory areas-permit such predictions, and CD abnormalities are a hypothesized mechanism for the agency disruptions in schizophrenia that characterize a subset of symptoms. Indeed, behavioral evidence of altered CD, including in the oculomotor system, has been observed in schizophrenia patients. A pathway projecting from the superior colliculus to the frontal eye fields (FEFs) via the mediodorsal thalamus (MD) conveys oculomotor CD associated with saccadic eye movements in nonhuman primates. This animal work provides a promising translational framework in which to investigate CD abnormalities in clinical populations. In the current study, we examined whether structural connectivity of this MD-FEF pathway relates to oculomotor CD functioning in schizophrenia. Twenty-two schizophrenia patients and 24 healthy control participants of both sexes underwent diffusion tensor imaging, and a large subset performed a trans-saccadic perceptual task that yields measures of CD. Using probabilistic tractography, we identified anatomical connections between FEF and MD and extracted indices of microstructural integrity. Patients exhibited compromised microstructural integrity in the MD-FEF pathway, which was correlated with greater oculomotor CD abnormalities and more severe psychotic symptoms. These data reinforce the role of the MD-FEF pathway in transmitting oculomotor CD signals and suggest that disturbances in this pathway may relate to psychotic symptom manifestation in patients.}, keywords = {}, pubstate = {published}, tppubtype = {article} } By predicting sensory consequences of actions, humans can distinguish self-generated sensory inputs from those that are elicited externally. This is one mechanism by which we achieve a subjective sense of agency over our actions. Corollary discharge (CD) signals-"copies" of motor signals sent to sensory areas-permit such predictions, and CD abnormalities are a hypothesized mechanism for the agency disruptions in schizophrenia that characterize a subset of symptoms. Indeed, behavioral evidence of altered CD, including in the oculomotor system, has been observed in schizophrenia patients. A pathway projecting from the superior colliculus to the frontal eye fields (FEFs) via the mediodorsal thalamus (MD) conveys oculomotor CD associated with saccadic eye movements in nonhuman primates. This animal work provides a promising translational framework in which to investigate CD abnormalities in clinical populations. In the current study, we examined whether structural connectivity of this MD-FEF pathway relates to oculomotor CD functioning in schizophrenia. Twenty-two schizophrenia patients and 24 healthy control participants of both sexes underwent diffusion tensor imaging, and a large subset performed a trans-saccadic perceptual task that yields measures of CD. Using probabilistic tractography, we identified anatomical connections between FEF and MD and extracted indices of microstructural integrity. Patients exhibited compromised microstructural integrity in the MD-FEF pathway, which was correlated with greater oculomotor CD abnormalities and more severe psychotic symptoms. These data reinforce the role of the MD-FEF pathway in transmitting oculomotor CD signals and suggest that disturbances in this pathway may relate to psychotic symptom manifestation in patients. |
Amit Yashar; Xiuyun Wu; Jiageng Chen; Marisa Carrasco Crowding and binding: Not all feature dimensions behave in the same way Journal Article Psychological Science, 30 (10), pp. 1533–1546, 2019. @article{Yashar2019, title = {Crowding and binding: Not all feature dimensions behave in the same way}, author = {Amit Yashar and Xiuyun Wu and Jiageng Chen and Marisa Carrasco}, doi = {10.1177/0956797619870779}, year = {2019}, date = {2019-01-01}, journal = {Psychological Science}, volume = {30}, number = {10}, pages = {1533--1546}, abstract = {Humans often fail to identify a target because of nearby flankers. The nature and stages at which this crowding occurs are unclear, and whether crowding operates via a common mechanism across visual dimensions is unknown. Using a dual-estimation report (N = 42), we quantitatively assessed the processing of features alone and in conjunction with another feature both within and between dimensions. Under crowding, observers misreported colors and orientations (i.e., reported a flanker value instead of the target's value) but averaged the target's and flankers' spatial frequencies (SFs). Interestingly, whereas orientation and color errors were independent, orientation and SF errors were interdependent. These qualitative differences of errors across dimensions revealed a tight link between crowding and feature binding, which is contingent on the type of feature dimension. These results and a computational model suggest that crowding and misbinding are due to pooling across a joint coding of orientations and SFs but not of colors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Humans often fail to identify a target because of nearby flankers. The nature and stages at which this crowding occurs are unclear, and whether crowding operates via a common mechanism across visual dimensions is unknown. Using a dual-estimation report (N = 42), we quantitatively assessed the processing of features alone and in conjunction with another feature both within and between dimensions. Under crowding, observers misreported colors and orientations (i.e., reported a flanker value instead of the target's value) but averaged the target's and flankers' spatial frequencies (SFs). Interestingly, whereas orientation and color errors were independent, orientation and SF errors were interdependent. These qualitative differences of errors across dimensions revealed a tight link between crowding and feature binding, which is contingent on the type of feature dimension. These results and a computational model suggest that crowding and misbinding are due to pooling across a joint coding of orientations and SFs but not of colors. |
Lok-Kin Yeung; Rosanna K Olsen; Bryan Hong; Valentina Mihajlovic; Maria C D'Angelo; Arber Kacollja; Jennifer D Ryan; Morgan D Barense Object-in-place memory predicted by anterolateral entorhinal cortex and parahippocampal cortex in older adults Journal Article Journal of Cognitive Neuroscience, 31 (5), pp. 711–729, 2019. @article{Yeung2019, title = {Object-in-place memory predicted by anterolateral entorhinal cortex and parahippocampal cortex in older adults}, author = {Lok-Kin Yeung and Rosanna K Olsen and Bryan Hong and Valentina Mihajlovic and Maria C D'Angelo and Arber Kacollja and Jennifer D Ryan and Morgan D Barense}, doi = {10.1162/jocn}, year = {2019}, date = {2019-01-01}, journal = {Journal of Cognitive Neuroscience}, volume = {31}, number = {5}, pages = {711--729}, abstract = {The lateral portion of the entorhinal cortex is one of the first brain regions affected by tau pathology, an important biomarker for Alzheimer disease. Improving our understanding of this region's cognitive role may help identify better cognitive tests for early detection of Alzheimer disease. Based on its functional connections, we tested the idea that the human anterolateral entorhinal cortex (alERC) may play a role in integrating spatial information into object representations. We recently demonstrated that the volume of the alERC was related to processing the spatial relationships of the features within an object [Yeung, L. K., Olsen, R. K., Bild-Enkin, H. E. P., D'Angelo, M. C., Kacollja, A., McQuiggan, D. A., et al. Anterolateral entorhinal cortex volume predicted by altered intra-item configural processing. Journal of Neuroscience, 37, 5527–5538, 2017]. In this study, we investi- gated whether the human alERC might also play a role in processing the spatial relationships between an object and its environment using an eye-tracking task that assessed visual fixations to a critical object within a scene. Guided by rodent work, we measured both object-in-place memory, the association of an object with a given context [Wilson, D. I., Langston, R. F., Schlesiger, M. I., Wagner, M., Watanabe, S., & Ainge, J. A. Lateral entorhinal cortex is critical for novel object-context recog- nition. Hippocampus, 23,352–366, 2013], and object-trace memory, the memory for the former location of objects [Tsao, A., Moser, M. B., & Moser, E. I. Traces of experience in the lateral entorhinal cortex. Current Biology, 23,399–405, 2013]. In a group of older adults with varying stages of brain atrophy and cognitive decline, we found that the volume of the alERC and the volume of the parahippocampal cortex selectively predicted object-in-place memory, but not object-trace memory. These results provide support for the notion that the alERC may integrate spatial information into object representations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The lateral portion of the entorhinal cortex is one of the first brain regions affected by tau pathology, an important biomarker for Alzheimer disease. Improving our understanding of this region's cognitive role may help identify better cognitive tests for early detection of Alzheimer disease. Based on its functional connections, we tested the idea that the human anterolateral entorhinal cortex (alERC) may play a role in integrating spatial information into object representations. We recently demonstrated that the volume of the alERC was related to processing the spatial relationships of the features within an object [Yeung, L. K., Olsen, R. K., Bild-Enkin, H. E. P., D'Angelo, M. C., Kacollja, A., McQuiggan, D. A., et al. Anterolateral entorhinal cortex volume predicted by altered intra-item configural processing. Journal of Neuroscience, 37, 5527–5538, 2017]. In this study, we investi- gated whether the human alERC might also play a role in processing the spatial relationships between an object and its environment using an eye-tracking task that assessed visual fixations to a critical object within a scene. Guided by rodent work, we measured both object-in-place memory, the association of an object with a given context [Wilson, D. I., Langston, R. F., Schlesiger, M. I., Wagner, M., Watanabe, S., & Ainge, J. A. Lateral entorhinal cortex is critical for novel object-context recog- nition. Hippocampus, 23,352–366, 2013], and object-trace memory, the memory for the former location of objects [Tsao, A., Moser, M. B., & Moser, E. I. Traces of experience in the lateral entorhinal cortex. Current Biology, 23,399–405, 2013]. In a group of older adults with varying stages of brain atrophy and cognitive decline, we found that the volume of the alERC and the volume of the parahippocampal cortex selectively predicted object-in-place memory, but not object-trace memory. These results provide support for the notion that the alERC may integrate spatial information into object representations. |
Chen Zhang; Angelina Paolozza; Po-He Tseng; James N Reynolds; Douglas P Munoz; Laurent Itti Detection of children/youth with fetal alcohol spectrum disorder through eye movement, psychometric, and neuroimaging data Journal Article Frontiers in Neurology, 10 , pp. 1–15, 2019. @article{Zhang2019a, title = {Detection of children/youth with fetal alcohol spectrum disorder through eye movement, psychometric, and neuroimaging data}, author = {Chen Zhang and Angelina Paolozza and Po-He Tseng and James N Reynolds and Douglas P Munoz and Laurent Itti}, doi = {10.3389/fneur.2019.00080}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Neurology}, volume = {10}, pages = {1--15}, abstract = {Background: Fetal alcohol spectrum disorders (FASD) is one of the most common causes of developmental disabilities and neurobehavioral deficits. Despite the high-prevalence of FASD, the current diagnostic process is challenging and time- and money-consuming, with underreported profiles of the neurocognitive and neurobehavioral impairments because of limited clinical capacity. We assessed children/youth with FASD from a multimodal perspective and developed a high-performing, low-cost screening protocol using a machine learning framework. Methods and Findings: Participants with FASD and age-matched typically developing controls completed up to six assessments, including saccadic eye movement tasks (prosaccade, antisaccade, and memory-guided saccade), free viewing of videos, psychometric tests, and neuroimaging of the corpus callosum. We comparatively investigated new machine learning methods applied to these data, toward the acquisition of a quantitative signature of the neurodevelopmental deficits, and the development of an objective, high-throughput screening tool to identify children/youth with FASD. Our method provides a comprehensive profile of distinct measures in domains including sensorimotor and visuospatial control, visual perception, attention, inhibition, working memory, academic functions, and brain structure. We also showed that a combination of four to six assessments yields the best FASD vs. control classification accuracy; however, this protocol is expensive and time consuming. We conducted a cost/benefit analysis of the six assessments and developed a high-performing, low-cost screening protocol based on a subset of eye movement and psychometric tests that approached the best result under a range of constraints (time, cost, participant age, required administration, and access to neuroimaging facility). Using insights from the theory of value of information, we proposed an optimal annual screening procedure for children at risk of FASD. Conclusions: We developed a high-capacity, low-cost screening procedure under constrains, with high expected monetary benefit, substantial impact of the referral and diagnostic process, and expected maximized long-term benefits to the tested individuals and to society. This annual screening procedure for children/youth at risk of FASD can be easily and widely deployed for early identification, potentially leading to earlier intervention and treatment. This is crucial for neurodevelopmental disorders, to mitigate the severity of the disorder and/or frequency of secondary comorbidities.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Fetal alcohol spectrum disorders (FASD) is one of the most common causes of developmental disabilities and neurobehavioral deficits. Despite the high-prevalence of FASD, the current diagnostic process is challenging and time- and money-consuming, with underreported profiles of the neurocognitive and neurobehavioral impairments because of limited clinical capacity. We assessed children/youth with FASD from a multimodal perspective and developed a high-performing, low-cost screening protocol using a machine learning framework. Methods and Findings: Participants with FASD and age-matched typically developing controls completed up to six assessments, including saccadic eye movement tasks (prosaccade, antisaccade, and memory-guided saccade), free viewing of videos, psychometric tests, and neuroimaging of the corpus callosum. We comparatively investigated new machine learning methods applied to these data, toward the acquisition of a quantitative signature of the neurodevelopmental deficits, and the development of an objective, high-throughput screening tool to identify children/youth with FASD. Our method provides a comprehensive profile of distinct measures in domains including sensorimotor and visuospatial control, visual perception, attention, inhibition, working memory, academic functions, and brain structure. We also showed that a combination of four to six assessments yields the best FASD vs. control classification accuracy; however, this protocol is expensive and time consuming. We conducted a cost/benefit analysis of the six assessments and developed a high-performing, low-cost screening protocol based on a subset of eye movement and psychometric tests that approached the best result under a range of constraints (time, cost, participant age, required administration, and access to neuroimaging facility). Using insights from the theory of value of information, we proposed an optimal annual screening procedure for children at risk of FASD. Conclusions: We developed a high-capacity, low-cost screening procedure under constrains, with high expected monetary benefit, substantial impact of the referral and diagnostic process, and expected maximized long-term benefits to the tested individuals and to society. This annual screening procedure for children/youth at risk of FASD can be easily and widely deployed for early identification, potentially leading to earlier intervention and treatment. This is crucial for neurodevelopmental disorders, to mitigate the severity of the disorder and/or frequency of secondary comorbidities. |
Xiaoxian Zhang; Wanlu Fu; Licheng Xue; Jing Zhao; Zhiguo Wang Children with mathematical learning difficulties are sluggish in disengaging attention Journal Article Frontiers in Psychology, 10 , pp. 1–9, 2019. @article{Zhang2019f, title = {Children with mathematical learning difficulties are sluggish in disengaging attention}, author = {Xiaoxian Zhang and Wanlu Fu and Licheng Xue and Jing Zhao and Zhiguo Wang}, doi = {10.3389/fpsyg.2019.00932}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Psychology}, volume = {10}, pages = {1--9}, abstract = {Mathematical learning difficulties (MLD) refer to a variety of deficits in math skills, typically pertaining to the domains of arithmetic and problem solving. The present study examined the time course of attentional orienting in MLD children with a spatial cueing task, by parametrically manipulating the cue-target onset asynchrony (CTOA). The results of Experiment 1 revealed that, in contrast to typical developing children, the inhibitory aftereffect of attentional orienting-frequently referred to as inhibition of return (IOR)-was not observed in the MLD children, even at the longest CTOA tested (800 ms). However, robust early facilitation effects were observed in the MLD children, suggesting that they have difficulties in attentional disengagement rather than attentional engagement. In a second experiment, a secondary cue was introduced to the cueing task to encourage attentional disengagement and IOR effects were observed in the MLD children. Taken together, the present experiments indicate that MLD children are sluggish in disengaging spatial attention.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Mathematical learning difficulties (MLD) refer to a variety of deficits in math skills, typically pertaining to the domains of arithmetic and problem solving. The present study examined the time course of attentional orienting in MLD children with a spatial cueing task, by parametrically manipulating the cue-target onset asynchrony (CTOA). The results of Experiment 1 revealed that, in contrast to typical developing children, the inhibitory aftereffect of attentional orienting-frequently referred to as inhibition of return (IOR)-was not observed in the MLD children, even at the longest CTOA tested (800 ms). However, robust early facilitation effects were observed in the MLD children, suggesting that they have difficulties in attentional disengagement rather than attentional engagement. In a second experiment, a secondary cue was introduced to the cueing task to encourage attentional disengagement and IOR effects were observed in the MLD children. Taken together, the present experiments indicate that MLD children are sluggish in disengaging spatial attention. |
Peng Zhou; Weiyi Ma; Likan Zhan A deficit in using prosodic cues to understand communicative intentions by children with autism spectrum disorders: An eye-tracking study Journal Article First Language, pp. 1–13, 2019. @article{Zhou2019, title = {A deficit in using prosodic cues to understand communicative intentions by children with autism spectrum disorders: An eye-tracking study}, author = {Peng Zhou and Weiyi Ma and Likan Zhan}, doi = {10.1177/0142723719885270}, year = {2019}, date = {2019-01-01}, journal = {First Language}, pages = {1--13}, abstract = {The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorders (ASD) were able to use prosodic cues to understand others' communicative intentions. Using the visual world eye-tracking paradigm, the study found that unlike typically developing (TD) 4-year-olds, both 4-year-olds with ASD and 5-year-olds with ASD exhibited an eye gaze pattern that reflected their inability to use prosodic cues to infer the intended meaning of the speaker. Their performance was relatively independent of their verbal IQ and mean length of utterance. In addition, the findings also show that there was no development in this ability from 4 years of age to 5 years of age. The findings indicate that Mandarin-speaking preschool children with ASD exhibit a deficit in using prosodic cues to understand the communicative intentions of the speaker, and this ability might be inherently impaired in ASD.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorders (ASD) were able to use prosodic cues to understand others' communicative intentions. Using the visual world eye-tracking paradigm, the study found that unlike typically developing (TD) 4-year-olds, both 4-year-olds with ASD and 5-year-olds with ASD exhibited an eye gaze pattern that reflected their inability to use prosodic cues to infer the intended meaning of the speaker. Their performance was relatively independent of their verbal IQ and mean length of utterance. In addition, the findings also show that there was no development in this ability from 4 years of age to 5 years of age. The findings indicate that Mandarin-speaking preschool children with ASD exhibit a deficit in using prosodic cues to understand the communicative intentions of the speaker, and this ability might be inherently impaired in ASD. |
Peng Zhou; Likan Zhan; Huimin Ma Predictive language processing in preschool children with autism spectrum disorder: An eye-tracking study Journal Article Journal of Psycholinguistic Research, 48 (2), pp. 431–452, 2019. @article{Zhou2019d, title = {Predictive language processing in preschool children with autism spectrum disorder: An eye-tracking study}, author = {Peng Zhou and Likan Zhan and Huimin Ma}, doi = {10.1007/s10936-018-9612-5}, year = {2019}, date = {2019-01-01}, journal = {Journal of Psycholinguistic Research}, volume = {48}, number = {2}, pages = {431--452}, publisher = {Springer US}, abstract = {Sentence comprehension relies on the abilities to rapidly integrate different types of linguistic and non-linguistic information. The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorder (ASD) are able to use verb information predictively to anticipate the upcoming linguistic input during real-time sentence comprehension. 26 five-year-olds with ASD, 25 typically developing (TD) five-year-olds and 24 TD four-year-olds were tested using the visual world eye-tracking paradigm. The results showed that the 5-year-olds with ASD, like their TD peers, exhibited verb-based anticipatory eye movements during real-time sentence comprehension. No difference was observed between the ASD and TD groups in the time course of their eye gaze patterns, indicating that Mandarin-speaking preschool children with ASD are able to use verb information as effectively and rapidly as TD peers to predict the upcoming linguistic input.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sentence comprehension relies on the abilities to rapidly integrate different types of linguistic and non-linguistic information. The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorder (ASD) are able to use verb information predictively to anticipate the upcoming linguistic input during real-time sentence comprehension. 26 five-year-olds with ASD, 25 typically developing (TD) five-year-olds and 24 TD four-year-olds were tested using the visual world eye-tracking paradigm. The results showed that the 5-year-olds with ASD, like their TD peers, exhibited verb-based anticipatory eye movements during real-time sentence comprehension. No difference was observed between the ASD and TD groups in the time course of their eye gaze patterns, indicating that Mandarin-speaking preschool children with ASD are able to use verb information as effectively and rapidly as TD peers to predict the upcoming linguistic input. |
Jing Zhu; Ying Wang; Rong La; Jiawei Zhan; Junhong Niu; Shuai Zeng; Xiping Hu Multimodal mild depression recognition based on EEG-EM synchronization acquisition network Journal Article IEEE Access, 7 , pp. 28196–28210, 2019. @article{Zhu2019b, title = {Multimodal mild depression recognition based on EEG-EM synchronization acquisition network}, author = {Jing Zhu and Ying Wang and Rong La and Jiawei Zhan and Junhong Niu and Shuai Zeng and Xiping Hu}, doi = {10.1109/ACCESS.2019.2901950}, year = {2019}, date = {2019-01-01}, journal = {IEEE Access}, volume = {7}, pages = {28196--28210}, publisher = {IEEE}, abstract = {In this paper, we used electroencephalography (EEG)-eye movement (EM) synchronization acquisition network to simultaneously record both EEG and EM physiological signals of the mild depression and normal controls during free viewing. Then, we consider a multimodal feature fusion method that can best discriminate between mild depression and normal control subjects as a step toward achieving our long-term aim of developing an objective and effective multimodal system that assists doctors during diagnosis and monitoring of mild depression. Based on the multimodal denoising autoencoder, we use two feature fusion strategies (feature fusion and hidden layer fusion) for fusion of the EEG and EM signals to improve the recognition performance of classifiers for mild depression. Our experimental results indicate that the EEG-EM synchronization acquisition network ensures that the recorded EM and EEG data require that both the data streams are synchronized with millisecond precision, and both fusion methods can improve the mild depression recognition accuracy, thus demonstrating the complementary nature of the modalities. Compared with the unimodal classification approach that uses only EEG or EM, the feature fusion method slightly improved the recognition accuracy by 1.88%, while the hidden layer fusion method significantly improved the classification rate by up to 7.36%. In particular, the highest classification accuracy achieved in this paper was 83.42%. These results indicate that the multimodal deep learning approaches with input data using a combination of EEG and EM signals are promising in achieving real-time monitoring and identification of mild depression.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, we used electroencephalography (EEG)-eye movement (EM) synchronization acquisition network to simultaneously record both EEG and EM physiological signals of the mild depression and normal controls during free viewing. Then, we consider a multimodal feature fusion method that can best discriminate between mild depression and normal control subjects as a step toward achieving our long-term aim of developing an objective and effective multimodal system that assists doctors during diagnosis and monitoring of mild depression. Based on the multimodal denoising autoencoder, we use two feature fusion strategies (feature fusion and hidden layer fusion) for fusion of the EEG and EM signals to improve the recognition performance of classifiers for mild depression. Our experimental results indicate that the EEG-EM synchronization acquisition network ensures that the recorded EM and EEG data require that both the data streams are synchronized with millisecond precision, and both fusion methods can improve the mild depression recognition accuracy, thus demonstrating the complementary nature of the modalities. Compared with the unimodal classification approach that uses only EEG or EM, the feature fusion method slightly improved the recognition accuracy by 1.88%, while the hidden layer fusion method significantly improved the classification rate by up to 7.36%. In particular, the highest classification accuracy achieved in this paper was 83.42%. These results indicate that the multimodal deep learning approaches with input data using a combination of EEG and EM signals are promising in achieving real-time monitoring and identification of mild depression. |
Roy Amit; Dekel Abeles; Marisa Carrasco; Shlomit Yuval-Greenberg Oculomotor inhibition reflects temporal expectations Journal Article NeuroImage, 184 , pp. 279–292, 2019. @article{Amit2019a, title = {Oculomotor inhibition reflects temporal expectations}, author = {Roy Amit and Dekel Abeles and Marisa Carrasco and Shlomit Yuval-Greenberg}, doi = {10.1016/j.neuroimage.2018.09.026}, year = {2019}, date = {2019-01-01}, journal = {NeuroImage}, volume = {184}, pages = {279--292}, abstract = {The accurate extraction of signals out of noisy environments is a major challenge of the perceptual system. Forming temporal expectations and continuously matching them with perceptual input can facilitate this process. In humans, temporal expectations are typically assessed using behavioral measures, which provide only retrospective but no real-time estimates during target anticipation, or by using electrophysiological measures, which require extensive preprocessing and are difficult to interpret. Here we show a new correlate of temporal expectations based on oculomotor behavior. Observers performed an orientation-discrimination task on a central grating target, while their gaze position and EEG were monitored. In each trial, a cue preceded the target by a varying interval (“foreperiod”). In separate blocks, the cue was either predictive or non-predictive regarding the timing of the target. Results showed that saccades and blinks were inhibited more prior to an anticipated regular target than a less-anticipated irregular one. This consistent oculomotor inhibition effect enabled a trial-by-trial classification according to interval-regularity. Additionally, in the regular condition the slope of saccade-rate and drift were shallower for longer than shorter foreperiods, indicating their adjustment according to temporal expectations. Comparing the sensitivity of this oculomotor marker with those of other common predictability markers (e.g. alpha-suppression) showed that it is a sensitive marker for cue-related anticipation. In contrast, temporal changes in conditional probabilities (hazard-rate) modulated alpha-suppression more than cue-related anticipation. We conclude that pre-target oculomotor inhibition is a correlate of temporal predictions induced by cue-target associations, whereas alpha-suppression is more sensitive to conditional probabilities across time.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The accurate extraction of signals out of noisy environments is a major challenge of the perceptual system. Forming temporal expectations and continuously matching them with perceptual input can facilitate this process. In humans, temporal expectations are typically assessed using behavioral measures, which provide only retrospective but no real-time estimates during target anticipation, or by using electrophysiological measures, which require extensive preprocessing and are difficult to interpret. Here we show a new correlate of temporal expectations based on oculomotor behavior. Observers performed an orientation-discrimination task on a central grating target, while their gaze position and EEG were monitored. In each trial, a cue preceded the target by a varying interval (“foreperiod”). In separate blocks, the cue was either predictive or non-predictive regarding the timing of the target. Results showed that saccades and blinks were inhibited more prior to an anticipated regular target than a less-anticipated irregular one. This consistent oculomotor inhibition effect enabled a trial-by-trial classification according to interval-regularity. Additionally, in the regular condition the slope of saccade-rate and drift were shallower for longer than shorter foreperiods, indicating their adjustment according to temporal expectations. Comparing the sensitivity of this oculomotor marker with those of other common predictability markers (e.g. alpha-suppression) showed that it is a sensitive marker for cue-related anticipation. In contrast, temporal changes in conditional probabilities (hazard-rate) modulated alpha-suppression more than cue-related anticipation. We conclude that pre-target oculomotor inhibition is a correlate of temporal predictions induced by cue-target associations, whereas alpha-suppression is more sensitive to conditional probabilities across time. |
Roy Amit; Dekel Abeles; Shlomit Yuval-Greenberg Transient and sustained effects of stimulus properties on the generation of microsaccades Journal Article Journal of Vision, 19 (1), pp. 1–23, 2019. @article{Amit2019b, title = {Transient and sustained effects of stimulus properties on the generation of microsaccades}, author = {Roy Amit and Dekel Abeles and Shlomit Yuval-Greenberg}, doi = {10.1167/19.1.6}, year = {2019}, date = {2019-01-01}, journal = {Journal of Vision}, volume = {19}, number = {1}, pages = {1--23}, publisher = {The Association for Research in Vision and Ophthalmology}, abstract = {Saccades shift the gaze rapidly every few hundred milliseconds from one fixated location to the next, producing a flow of visual input into the visual system even in the absence of changes in the environment. During fixation, small saccades called microsaccades are produced 1–3 times per second, generating a flow of visual input. The characteristics of this visual flow are determined by the timings of the saccades and by the characteristics of the visual stimuli on which they are performed. Previous models of microsaccade generation have accounted for the effects of external stimulation on the production of microsaccades, but they have not considered the effects of the prolonged background stimulus on which microsaccades are performed. The effects of this stimulus on the process of microsaccade generation could be sustained, following its prolonged presentation, or transient, through the visual transients produced by the microsaccades themselves. In four experiments, we varied the properties of the constant displays and examined the resulting modulation of microsaccade properties: their sizes, their timings, and the correlations between properties of consecutive microsaccades. Findings show that displays of higher spatial frequency and contrast produce smaller microsaccades and longer minimal intervals between consecutive microsaccades; and smaller microsaccades are followed by smaller and delayed microsaccades. We explain these findings in light of previous models and suggest a conceptual model by which both sustained and transient effects of the stimulus have central roles in determining the generation of microsaccades.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Saccades shift the gaze rapidly every few hundred milliseconds from one fixated location to the next, producing a flow of visual input into the visual system even in the absence of changes in the environment. During fixation, small saccades called microsaccades are produced 1–3 times per second, generating a flow of visual input. The characteristics of this visual flow are determined by the timings of the saccades and by the characteristics of the visual stimuli on which they are performed. Previous models of microsaccade generation have accounted for the effects of external stimulation on the production of microsaccades, but they have not considered the effects of the prolonged background stimulus on which microsaccades are performed. The effects of this stimulus on the process of microsaccade generation could be sustained, following its prolonged presentation, or transient, through the visual transients produced by the microsaccades themselves. In four experiments, we varied the properties of the constant displays and examined the resulting modulation of microsaccade properties: their sizes, their timings, and the correlations between properties of consecutive microsaccades. Findings show that displays of higher spatial frequency and contrast produce smaller microsaccades and longer minimal intervals between consecutive microsaccades; and smaller microsaccades are followed by smaller and delayed microsaccades. We explain these findings in light of previous models and suggest a conceptual model by which both sustained and transient effects of the stimulus have central roles in determining the generation of microsaccades. |
Jeremy B Badler; Scott N J Watamaniuk; Stephen J Heinen A common mechanism modulates saccade timing during pursuit and fixation Journal Article Journal of Neurophysiology, 122 (5), pp. 1981–1988, 2019. @article{Badler2019, title = {A common mechanism modulates saccade timing during pursuit and fixation}, author = {Jeremy B Badler and Scott N J Watamaniuk and Stephen J Heinen}, year = {2019}, date = {2019-01-01}, journal = {Journal of Neurophysiology}, volume = {122}, number = {5}, pages = {1981--1988}, abstract = {Smooth pursuit is punctuated by catch-up saccades, which are thought to automatically correct sensory errors in retinal position and velocity. Recent studies have shown that the timing of catch-up saccades is susceptible to cognitive modulation, as is the timing of fixational microsaccades. Are the timing of catchup and microsaccades thus modulated by the same mechanism? Here, we test directly whether pursuit catch-up saccades and fixational microsaccades exhibit the same temporal pattern of task-related bursts and subsidence. Observers pursued a linear array of 15 alphanumeric characters that translated across the screen and simultaneously performed a character identification task on it. At a fixed time, a cue briefly surrounded the central element to specify it as the pursuit target. After a random delay, a probe (E or 3) appeared briefly at a randomly selected character location, and observers identified it. For comparison, a fixation condition was also tested with trial parameters identical to the pursuit condition, except that the array remained stationary. We found that during both pursuit and fixation tasks, saccades paused after the cue and then rebounded as expected but also subsided in anticipation of the task. The time courses of the reactive pause, rebound, and anticipatory subsidence were similar, and idiosyncratic subject behavior was consistent across pursuit and fixation. The results provide evidence for a common mechanism of saccade control during pursuit and fixation, which is predictive as well as reactive and has an identifiable temporal signature in individual observers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Smooth pursuit is punctuated by catch-up saccades, which are thought to automatically correct sensory errors in retinal position and velocity. Recent studies have shown that the timing of catch-up saccades is susceptible to cognitive modulation, as is the timing of fixational microsaccades. Are the timing of catchup and microsaccades thus modulated by the same mechanism? Here, we test directly whether pursuit catch-up saccades and fixational microsaccades exhibit the same temporal pattern of task-related bursts and subsidence. Observers pursued a linear array of 15 alphanumeric characters that translated across the screen and simultaneously performed a character identification task on it. At a fixed time, a cue briefly surrounded the central element to specify it as the pursuit target. After a random delay, a probe (E or 3) appeared briefly at a randomly selected character location, and observers identified it. For comparison, a fixation condition was also tested with trial parameters identical to the pursuit condition, except that the array remained stationary. We found that during both pursuit and fixation tasks, saccades paused after the cue and then rebounded as expected but also subsided in anticipation of the task. The time courses of the reactive pause, rebound, and anticipatory subsidence were similar, and idiosyncratic subject behavior was consistent across pursuit and fixation. The results provide evidence for a common mechanism of saccade control during pursuit and fixation, which is predictive as well as reactive and has an identifiable temporal signature in individual observers. |
Rodrigo Balp; Florian Waszak; Thérèse Collins Remapping versus short-term memory in visual stability across saccades Journal Article Attention, Perception, & Psychophysics, 81 , pp. 98–108, 2019. @article{Balp2019, title = {Remapping versus short-term memory in visual stability across saccades}, author = {Rodrigo Balp and Florian Waszak and Thér{è}se Collins}, doi = {10.3758/s13414-018-1602-z}, year = {2019}, date = {2019-01-01}, journal = {Attention, Perception, & Psychophysics}, volume = {81}, pages = {98--108}, publisher = {Attention, Perception, & Psychophysics}, abstract = {Saccadic eye movements cause displacements of the image of the visual world projected on the retina. Despite the ubiquitous nature of saccades, subjective experience of the world is continuous and stable. In five experiments, we addressed the mechanisms that may support visual stability: matching of pre- and postsaccadic locations of the target by an internal copy of the saccade, or retention of the visual attributes of the target in short-term memory across the saccade. Healthy human adults were instructed to make a saccade to a peripheral Gabor patch. While the saccade was in midflight, the patch could change location, orientation, or both. The change occurred either immediately or following a 250-ms blank during which no visual stimuli were available. In separate experiments, subjects had to report either whether the patch stepped to the left or right or whether the orientation rotated clockwise or counterclockwise. Consistent with previous findings, we found that transsaccadic displacement discrimination was enhanced by the addition of the blank. However, contrary to previous findings reported in the literature, the feature change did not improve performance. Transsaccadic orientation change discrimination did not depend on either an irrelevant temporal blank or a simultaneous irrelevant target displacement. Taken together, these findings suggest that orientation is not a relevant visual feature for transsaccadic correspondence.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Saccadic eye movements cause displacements of the image of the visual world projected on the retina. Despite the ubiquitous nature of saccades, subjective experience of the world is continuous and stable. In five experiments, we addressed the mechanisms that may support visual stability: matching of pre- and postsaccadic locations of the target by an internal copy of the saccade, or retention of the visual attributes of the target in short-term memory across the saccade. Healthy human adults were instructed to make a saccade to a peripheral Gabor patch. While the saccade was in midflight, the patch could change location, orientation, or both. The change occurred either immediately or following a 250-ms blank during which no visual stimuli were available. In separate experiments, subjects had to report either whether the patch stepped to the left or right or whether the orientation rotated clockwise or counterclockwise. Consistent with previous findings, we found that transsaccadic displacement discrimination was enhanced by the addition of the blank. However, contrary to previous findings reported in the literature, the feature change did not improve performance. Transsaccadic orientation change discrimination did not depend on either an irrelevant temporal blank or a simultaneous irrelevant target displacement. Taken together, these findings suggest that orientation is not a relevant visual feature for transsaccadic correspondence. |
Marie E Bellet; Joachim Bellet; Hendrikje Nienborg; Ziad M Hafed; Philipp Berens Human-level saccade detection performance using deep neural networks Journal Article Journal of Neurophysiology, 121 (2), pp. 646–661, 2019. @article{Bellet2019, title = {Human-level saccade detection performance using deep neural networks}, author = {Marie E Bellet and Joachim Bellet and Hendrikje Nienborg and Ziad M Hafed and Philipp Berens}, doi = {10.1152/jn.00601.2018}, year = {2019}, date = {2019-01-01}, journal = {Journal of Neurophysiology}, volume = {121}, number = {2}, pages = {646--661}, abstract = {Saccades are ballistic eye movements that rapidly shift gaze from one location of visual space to another. Detecting saccades in eye movement recordings is important not only for studying the neural mechanisms underlying sensory, motor, and cognitive processes, but also as a clinical and diagnostic tool. However, automatically detecting saccades can be difficult, particularly when such saccades are generated in coordination with other tracking eye movements, like smooth pursuits, or when the saccade amplitude is close to eye tracker noise levels, like with microsaccades. In such cases, labeling by human experts is required, but this is a tedious task prone to variability and error. We developed a convolutional neural network to automatically detect saccades at human-level accuracy and with minimal training examples. Our algorithm surpasses state of the art according to common performance metrics and could facilitate studies of neurophysiological processes underlying saccade generation and visual processing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Saccades are ballistic eye movements that rapidly shift gaze from one location of visual space to another. Detecting saccades in eye movement recordings is important not only for studying the neural mechanisms underlying sensory, motor, and cognitive processes, but also as a clinical and diagnostic tool. However, automatically detecting saccades can be difficult, particularly when such saccades are generated in coordination with other tracking eye movements, like smooth pursuits, or when the saccade amplitude is close to eye tracker noise levels, like with microsaccades. In such cases, labeling by human experts is required, but this is a tedious task prone to variability and error. We developed a convolutional neural network to automatically detect saccades at human-level accuracy and with minimal training examples. Our algorithm surpasses state of the art according to common performance metrics and could facilitate studies of neurophysiological processes underlying saccade generation and visual processing. |