EyeLink Cognitive Publications
All EyeLink cognitive and perception research publications up until 2023 (with some early 2024s) are listed below by year. You can search the publications using keywords such as Visual Search, Scene Perception, Face Processing, etc. You can also search for individual author names. If we missed any EyeLink cognitive or perception articles, please email us!
2017 |
Qingxiao Liu; Bo Tan; Jing Zhou; Zhong Zheng; Ling Li; Yanchun Yang Pathophysiology of refractory obsessive-compulsive disorder Journal Article In: Medicine, pp. 1–11, 2017. @article{Liu2017d, Based on both functional and structural studies of excessive activity, fronto-striatal-thalamic-cortical and cortico-striatal circuits have been hypothesized to underlie the pathophysiology of obsessive-compulsive disorder (OCD). However, the neurobiological underpinnings of OCD refractory to medication and therapy remain controversial. This study aimed to evaluate neuroanatomical abnormalities of the whole brain and to evaluate visual processing in patients with refractory OCD. This study was comprised of 2 experiments. The neuroanatomical abnormalities of the whole brain were evaluated using a visual search in combination with overactive performance monitoring (Experiment I), and visual processing was evaluated using event- related potentials recorded from subjects during performance of a visual search task. We also examined the amplitudes and latency of the error-related negativity (ERN) using a modified flanker task (Experiment II). Standard low-resolution electromagnetic tomography analysis was applied to determine the special areas. Patients with refractory OCD had a significantly greater number of saccades and prolonged latencies relative to the healthy controls. Scalp map topography confirmed that visual cognitive and executive dysfunction was localized to the fusiform gyrus. Furthermore, we found that during a modified flanker task, ERNs had a greater amplitude and a prolonged latency relative to those of the healthy controls. Further data analysis suggested that cognitive dysfunction and compulsive behavior in OCD patients were linked to abnormalities within the dorsolateral prefrontal cortex (DLPFC). We identified abnormal activities within the fusiform gyrus and DLPFC that likely play important roles in the pathophysiology of OCD. |
Zhong-Xu Liu; Kelly Shen; Rosanna K. Olsen; Jennifer D. Ryan Visual sampling predicts hippocampal activity Journal Article In: Journal of Neuroscience, vol. 37, no. 3, pp. 599–609, 2017. @article{Liu2017c, Eye movements serve to accumulate information from the visual world, contributing to the formation of coherent memory representations that support cognition and behavior. The hippocampus and the oculomotor network are well connected anatomically through an extensive set of polysynaptic pathways. However, the extent to which visual sampling behavior is related to functional responses in the hippocampus during encoding has not been studied directly in human neuroimaging. In the current study, participants engaged in a face processing task while brain responses were recorded with fMRI and eye movements were monitored simultaneously. The number of gaze fixations that a participant made on a given trial was correlated significantly with hippocampal activation such that more fixations were associated with stronger hippocampal activation. Similar results were also found in the fusiform face area, a face-selective perceptual processing region. Notably, the number of fixations was associated with stronger hippocampal activation when the presented faces were novel, but not when the faces were repeated. Increases in fixations during viewing of novel faces also led to larger repetition-related suppression in the hippocampus, indicating that this fixation–hippocampal relationship may reflect the ongoing development of lasting representations. Together, these results provide novel empirical support for the idea that visual exploration and hippocampal binding processes are inherently linked. |
Barbara C. Y. Lo; Jeffrey C. C. Liu Executive control in depressive rumination: Backward inhibition and non-inhibitory switching performance in a modified mixed antisaccade task Journal Article In: Frontiers in Psychology, vol. 8, pp. 136, 2017. @article{Lo2017, BACKGROUND AND OBJECTIVES: The present study examines backward inhibition (BI) and non-inhibitory switching performance among depressed and healthy participants in a modified mixed antisaccade task. Specifically, sad and neutral faces were incorporated in the design to examine executive control difficulties associated with brooding trait. METHODS: Thirty-nine participants took part in the study, including 19 depressed patients and 20 healthy control subjects. Participants completed a diagnostic interview and self-report questionnaires, including the Beck Depression Inventory and Ruminative Response Scale-Brooding Subscale. They were then instructed to complete prosaccade and antisaccade trials in the pure and mixed blocks whereby eye gazes were tracked to assess inhibition and switching efficiency. RESULTS: For the switching effects, a significant group x brooding x task type interaction was found as hypothesized when multilevel modeling analysis was employed. Switching deficits associated with brooding was found to be greatest when sad faces were presented to depressed group. No significant results in BI or error rates were observed. CONCLUSION: The patterns observed suggest that as opposed to BI, set shifting difficulty associated with brooding trait may be modulated by negative mood and cognition. In future research, emotional faces other than sad faces may be used to further explore if the observations could be generalized to other affective conditions. |
Zhongling Pi; Jianzhong Hong; Jiumin Yang Effects of the instructor's pointing gestures on learning performance in video lectures Journal Article In: British Journal of Educational Technology, vol. 48, no. 4, pp. 1020–1029, 2017. @article{Pi2017, Recent research on video lectures has indicated that the instructor's pointing gestures facilitate learning performance. This study examined whether the instructor's pointing gestures were superior to nonhuman cues in enhancing video lectures learning, and second, if there was a positive effect, what the underlying mechanisms of the effect might be. There were three kinds of video lectures in the study: one with the instructor's pointing gestures, one with nonhuman cues, and one without any cues. Eighty-four Chinese undergraduates were randomly assigned to view one of the three video lectures in a laboratory. As hypothesized, the results of analyses of variance showed that the instructor's pointing gestures improved learning performance more than the nonhuman cues and no-cues conditions. The pointing gestures directed the learners' visual attention to the relevant learning content of PowerPoint (PPT) slides in the video lecture. This suggests that the instructor's pointing gestures can be a valuable means to improve learning performance in video lectures, in particular PPT slides with much learning information. |
Charisse B. Pickron; Eswen Fava; Lisa S. Scott Follow my gaze: Face race and sex influence gaze-cued attention in infancy Journal Article In: Infancy, vol. 22, no. 5, pp. 626–644, 2017. @article{Pickron2017, Using the eye gaze of others to direct one's own attention develops during the first year of life and is thought to be an important skill for learning and social communication. However, it is currently unclear whether infants differentially attend to and encode objects cued by the eye gaze of individuals within familiar groups (e.g., own race, more familiar sex) relative to unfamiliar groups (e.g., other race, less familiar sex). During gaze cueing, but prior to the presentation of objects, 10-month-olds looked longer to the eyes of own-race faces relative to 5-month-olds and relative to the eyes of other-race faces. After gaze cueing, two objects were presented alongside the face and at both ages, infants looked longer to the uncued objects for faces from the more familiar-sex and longer to cued objects for the less familiar-sex faces. Finally, during the test phase, both 5- and 10-month-old infants looked longer to uncued objects relative to cued objects but only when the objects were cued by an own-race and familiar-sex individual. Results demonstrate that infants use face eye gaze differently when the cue comes from someone within a highly experienced group. |
Allison M. Pierce; Monique D. Crouse; Jessica J. Green Evidence for an attentional component of inhibition of return in visual search Journal Article In: Psychophysiology, vol. 54, no. 11, pp. 1676–1685, 2017. @article{Pierce2017a, Inhibition of return (IOR) is typically described as an inhibitory bias against returning attention to a recently attended location as a means of promoting efficient visual search. Most studies examining IOR, however, either do not use visual search para- digms or do not effectively isolate attentional processes, making it difficult to conclusively link IOR to a bias in attention. Here, we recorded ERPs during a simple visual search task designed to isolate the attentional component of IOR to examine whether an inhibitory bias of attention is observed and, if so, how it influences visual search behavior. Across successive visual search displays, we found evidence of both a broad, hemisphere-wide inhibitory bias of attention along with a focal, target location-specific facilitation. When the target appeared in the same visual hemifield in successive searches, responses were slower and the N2pc component was reduced, reflecting a bias of attention away from the previously attended side of space. When the target occurred at the same location in successive searches, responses were facili- tated and the P1 component was enhanced, likely reflecting spatial priming of the target. These two effects are combined in the response times, leading to a reduction in the IOR effect for repeated target locations. Using ERPs, however, these two opposing effects can be isolated in time, demonstrating that the inhibitory biasing of attention still occurs even when response-time slowing is ameliorated by spatial priming. |
Jordan E. Pierce; Jennifer E. McDowell Reduced cognitive control demands after practice of saccade tasks in a trial type probability manipulation Journal Article In: Journal of Cognitive Neuroscience, vol. 29, no. 2, pp. 368–381, 2017. @article{Pierce2017, Cognitive control is engaged to facilitate stimulus–response mappings for novel, complex tasks and supervise performance in unfamiliar, challenging contexts—processes supported by pFC, ACC, and posterior parietal cortex. With repeated task practice, however, the appropriate task set can be selected in a more automatic fashion with less need for top–down cognitive control and weaker activation in these brain regions. One model system for investigating cognitive control is the ocular motor circuitry underlying saccade production, with basic pro- saccade trials (look toward a stimulus) and complex antisaccade trials (look to the mirror image location) representing low and high levels of cognitive control, respectively. Previous studies have shown behavioral improvements on saccade tasks after practice with contradictory results regarding the direction of functional MRI BOLD signal change. The current study presented healthy young adults with prosaccade and antisaccade trials in five mixed blocks with varying probability of each trial type (0%, 25%, 50%, 75%, or 100% anti vs. pro) at baseline and posttest MRI sessions. Between the scans, participants practiced either the specific probability blocks used during testing or only a general 100% antisaccade block. Results indicated an overall re- duction in BOLD activation within pFC, ACC, and posterior parietal cortex and across saccade circuitry for antisaccade trials. The specific practice group showed additional regions including ACC, insula, and thalamus with an activation decrease after practice, whereas the general practice group showed a little change from baseline in those clusters. These findings demonstrate that cog- nitive control regions recruited to support novel task behaviors were engaged less after practice, especially with exposure to mixed task contexts rather than a novel task in isolation. |
Alessandro Piras; Milena Raffi; Monica Perazzolo; Ivan M. Lanzoni; Salvatore Squatrito; Ivan Malagoli Lanzoni Microsaccades and interest areas during free-viewing sport task Journal Article In: Journal of Sports Sciences, pp. 1–8, 2017. @article{Piras2017, Microsaccades are important fixation eye movements for visual scene perception. Compared to novices, athletes make fewer fixations of longer duration toward limited interest areas crucial for action prediction. Thus, our aim was to study the microsaccade features during those fixations. Gaze behaviour of expert and novice table tennis players was recorder during a task in which subjects were instructed to predict the direction of the ball after the opponent's throw. Three interest areas from the opponent's body and one from the ball trajectory were identified. We analysed correctness of predictions, fixations, microsaccades and saccades to estimate the relationship between eye movements toward interest areas and success in the task. Compared to novices, experts fixated more on hand-racket during forehand and on trunk during backhand drive technique. Longer fixations on hand-racket and trunk were associated with higher microsaccade rate with a narrower directional distribution of them. It probably means that athletes focused their gaze on these small areas, suggesting enhanced attention mainly to them, and fewer consideration for the surrounding regions. We can assume that microsaccade rate and average direction could be related to the salience of interest areas during performance. |
Patrick Plummer; Melissa DeWolf; Miriam Bassok; Peter C. Gordon; Keith J. Holyoak Reasoning strategies with rational numbers revealed by eye tracking Journal Article In: Attention, Perception, and Psychophysics, vol. 79, no. 5, pp. 1426–1437, 2017. @article{Plummer2017, Recent research has begun to investigate the impact of different formats for rational numbers on the processes by which people make relational judgments about quantitative relations. DeWolf, Bassok, and Holyoak (Journal of Experimental Psychology: General, 144(1), 127–150, 2015) found that accuracy on a relation identification task was highest when fractions were presented with countable sets, whereas accuracy was relatively low for all conditions where decimals were presented. However, it is unclear what process- ing strategies underlie these disparities in accuracy. We report an experiment that used eye-tracking methods to externalize the strategies that are evoked by different types of rational numbers for different types of quantities (discrete vs. continuous). Results showed that eye-movement behavior during the task was jointly determined by image and number format. Discrete images elicited a counting strategy for both fractions and decimals, but this strategy led to higher accuracy only for fractions. Continuous images encouraged magnitude estimation and comparison, but to a greater degree for decimals than fractions. This strategy led to decreased accuracy for both number formats. By analyzing participants' eye movements when they viewed a relational context and made decisions, we were able to obtain an externalized representation of the strategic choices evoked by different ontological types of entities and different types of rational numbers. Our findings using eye-tracking measures enable us to go beyond previous studies based on accuracy data alone, demonstrating that quantitative properties of images and the different formats for rational numbers jointly influence strategies that generate eye-movement behavior. |
Ulrich Pomper; Maria Chait The impact of visual gaze direction on auditory object tracking Journal Article In: Scientific Reports, vol. 7, pp. 4640, 2017. @article{Pomper2017, Subjective experience suggests that we are able to direct our auditory attention independent of our visual gaze, e.g when shadowing a nearby conversation at a cocktail party. But what are the consequences at the behavioural and neural level? While numerous studies have investigated both auditory attention and visual gaze independently, little is known about their interaction during selective listening. In the present EEG study, we manipulated visual gaze independently of auditory attention while participants detected targets presented from one of three loudspeakers. We observed increased response times when gaze was directed away from the locus of auditory attention. Further, we found an increase in occipital alpha-band power contralateral to the direction of gaze, indicative of a suppression of distracting input. Finally, this condition also led to stronger central theta-band power, which correlated with the observed effect in response times, indicative of differences in top-down processing. Our data suggest that a misalignment between gaze and auditory attention both reduce behavioural performance and modulate underlying neural processes. The involvement of central theta-band and occipital alpha-band effects are in line with compensatory neural mechanisms such as increased cognitive control and the suppression of task irrelevant inputs. |
Tzvetan Popov; Sabine Kastner; Ole Jensen FEF-controlled alpha delay activity precedes stimulus-induced gamma-band activity in visual cortex Journal Article In: Journal of Neuroscience, vol. 37, no. 15, pp. 4117–4127, 2017. @article{Popov2017, Recent findings in the visual system of nonhuman primates have demonstrated an important role of gamma-band activity (40–100 Hz) in the feedforward flow of sensory information, whereas feedback control appears to be established dynamically by oscillations in the alpha (8–13 Hz) and beta (13–18 Hz) bands (van Kerkoerle et al., 2014; Bastos et al., 2015). It is not clear, however, how alpha oscillations are controlled and how they interact with the flow of visual information mediated by gamma-band activity. Using noninvasive human MEG recordings in subjects performing a visuospatial attention task, we show that fluctuations in alpha power during a delay period in a spatial attention task preceded subsequent stimulus-driven gamma-band activity. Importantly, these interactions correlated with behavioral performance. Using Granger analysis, we further show that the right frontal-eye field (rFEF) exerted feedback control of the visual alpha oscillations. Our findings suggest that alpha oscillations controlled by the FEF route cortical information flow by modulating gamma-band activity. |
Florian Loffing; Stefanie Nickel; Norbert Hagemann Directionality in aesthetic judgments and performance evaluation: Sport judges and laypeople compared Journal Article In: Frontiers in Psychology, vol. 8, pp. 2109, 2017. @article{Loffing2017, Left-to-right readers are assumed to demonstrate a left-to-right bias in aesthetic preferences and performance evaluation. Here we tested the hypothesis that such bias occurs in left-to-right reading laypeople and gymnastic judges (n = 48 each) when asked to select the more beautiful image from a picture pair showing gymnastic or non-gymnastic actions (Experiment 1) and to evaluate videos of gymnasts' balance beam performances (Experiment 2). Overall, laypeople demonstrated a stronger left-to-right bias than judges. Unlike judges, laypeople rated images with left-to-right trajectory as more beautiful than content-wise identical images with right-to-left trajectory (Experiment 1). Also, laypeople tended to award slightly more points to videos showing left-to-right as opposed to right-to-left oriented actions (Experiment 2); however, in contrast to initial predictions the effect was weak and statistically unreliable. Collectively, judges, when considered as a group, seem less prone to directional bias than laypeople, thus tentatively suggesting that directionality may be an issue for unskilled but not for skilled judging. Possible mechanisms underlying the skill effect in Experiment 1 and the absence of clear bias in Experiment 2 are discussed alongside propositions for a broadening of perspectives in future research. |
Cai S. Longman; Aureliu Lavric; Stephen Monsell Self-paced preparation for a task switch eliminates attentional inertia but not the performance switch cost Journal Article In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 43, no. 6, pp. 862–873, 2017. @article{Longman2017, The performance overhead associated with changing tasks (the "switch cost") usually diminishes when the task is specified in advance but is rarely eliminated by preparation. A popular account of the "residual" (asymptotic) switch cost is that it reflects "task-set inertia": carry-over of task-set parameters from the preceding trial(s). New evidence for a component of "task-set inertia" comes from eye-tracking, where the location associated with the previously (but no longer) relevant task is fixated preferentially over other irrelevant locations, even when preparation intervals are generous. Might such limits in overcoming task-set inertia in general, and "attentional inertia" in particular, result from suboptimal scheduling of preparation when the time available is outside one's control? In the present study, the stimulus comprised 3 digits located at the points of an invisible triangle, preceded by a central verbal cue specifying which of 3 classification tasks to perform, each consistently applied to just 1 digit location. The digits were presented only when fixation moved away from the cue, thus giving the participant control over preparation time. In contrast to our previous research with experimenter-determined preparation intervals, we found no sign of attentional inertia for the long preparation intervals. Self-paced preparation reduced but did not eliminate the performance switch cost-leaving a clear residual component in both reaction time and error rates. That the scheduling of preparation accounts for some, but not all, components of the residual switch cost, challenges existing accounts of the switch cost, even those which distinguish between preparatory and poststimulus reconfiguration processes. |
Roman F. Loonis; Scott L. Brincat; Evan G. Antzoulatos; Earl K. Miller A meta-analysis suggests different neural correlates for implicit and explicit learning Journal Article In: Neuron, vol. 96, no. 2, pp. 521–534.e7, 2017. @article{Loonis2017, A meta-analysis of non-human primates performing three different tasks (Object-Match, Category-Match, and Category-Saccade associations) revealed signatures of explicit and implicit learning. Performance improved equally following correct and error trials in the Match (explicit) tasks, but it improved more after correct trials in the Saccade (implicit) task, a signature of explicit versus implicit learning. Likewise, error-related negativity, a marker for error processing, was greater in the Match (explicit) tasks. All tasks showed an increase in alpha/beta (10–30 Hz) synchrony after correct choices. However, only the implicit task showed an increase in theta (3–7 Hz) synchrony after correct choices that decreased with learning. In contrast, in the explicit tasks, alpha/beta synchrony increased with learning and decreased thereafter. Our results suggest that explicit versus implicit learning engages different neural mechanisms that rely on different patterns of oscillatory synchrony. Loonis et al. find that explicit and implicit learning use feedback about correct choices versus errors differently. Implicit learning relies more on theta synchrony (3–7 Hz) while explicit learning relies on alpha/beta synchrony (10–30 Hz). |
Jiachen Lu; Lili Tian; Jiafeng Zhang; Jing Wang; Chaoxiong Ye; Qiang Liu Strategic inhibition of distractors with visual working memory contents after involuntary attention capture Journal Article In: Scientific Reports, vol. 7, pp. 16314, 2017. @article{Lu2017, Previous research has suggested that visual working memory (VWM) contents had a guiding effect on selective attention, and once participants realized that the distractors shared the same information with VWM contents in the search task, they would strategically inhibit the potential distractors with VWM contents. However, previous behavioral studies could not reveal the way how distractors with VWM contents are inhibited strategically. By employing the eye-tracking technique and a dual-task paradigm, we manipulated the probability of memory items occurring as distractors to explore this issue. Consistent with previous behavioral studies, the results showed that the inhibitory effect occurred only in the high-probability condition, while the guiding effect emerged in the low-probability condition. More importantly, the eye-movement results indicated that in the high-probability condition, once few (even one) distractors with VWM contents were captured at first, all the remaining distractors with VWM contents would be rejected as a whole. However, in the low-probability condition, attention could be captured by the majority of distractors with VWM contents. These results suggested that the guiding effect of VWM contents on attention is involuntary in the early stage of visual search. After the completion of this involuntary stage, the guiding effect of task-irrelevant VWM contents on attention could be strategically controlled. |
Rachel G. Lucas-Thompson; Adina Dumitrache; Amy Quinn Sparks Appraisals of interparental conflict and change in attention to emotion after exposure to marital conflict Journal Article In: Journal of Child and Family Studies, vol. 26, no. 8, pp. 2175–2181, 2017. @article{LucasThompson2017, The goal of this study was to investigate whether exposure to marital conflict changes patterns of attention to anger and happiness, as well as whether those patterns vary based on appraisals of the history of interparental conflict in the home. Emerging adults viewed photo pairs with one emotionally-neutral photo and another photo depicting a happy/angry emotional interaction (while a high-speed camera tracked gaze), were randomly assigned to view a neutral or marital conflict recording, viewed neutral-emotional photo pairs again, and then reported their appraisals of their parents' conflict. Results indicated that feeling threatened by and to blame for parental conflict predicted avoidance of happy emotions at baseline. Although there were no significant changes in attention to emotion overall based on condition, self-blame for interparental conflict predicted greater increases in time spent looking at anger after watching marital conflict (but not after watching the neutral recording). These results indicate that differences in attention to emotion may be one mechanism linking parental conflict to anxiety that could be the focus of prevention/intervention efforts to reduce anxiety symptoms in those from high-conflict homes. |
Casimir J. H. Ludwig; David R. Evens Information foraging for perceptual decisions Journal Article In: Journal of Experimental Psychology: Human Perception and Performance, vol. 43, no. 2, pp. 245–264, 2017. @article{Ludwig2017, We tested an information foraging framework to characterize the mechanisms that drive active (visual) sampling behavior in decision problems that involve multiple sources of information. Experiments 1 through 3 involved participants making an absolute judgment about the direction of motion of a single random dot motion pattern. In Experiment 4, participants made a relative comparison between 2 motion patterns that could only be sampled sequentially. Our results show that: (a) Information (about noisy motion information) grows to an asymptotic level that depends on the quality of the information source; (b) The limited growth is attributable to unequal weighting of the incoming sensory evidence, with early samples being weighted more heavily; (c) Little information is lost once a new source of information is being sampled; and (d) The point at which the observer switches from 1 source to another is governed by online monitoring of his or her degree of (un)certainty about the sampled source. These findings demonstrate that the sampling strategy in perceptual decision-making is under some direct control by ongoing cognitive processing. More specifically, participants are able to track a measure of (un)certainty and use this information to guide their sampling behavior. |
Min-Yuan Ma; Hsien-Chih Chuang An exploratory study of the effect of enclosed structure on type design with fixation dispersion: Evidence from eye movements Journal Article In: International Journal of Technology and Design Education, vol. 27, no. 1, pp. 149–164, 2017. @article{Ma2017, Type design is the process of re-organizing visual elements and their corresponding meanings into a new organic entity, particularly for the highly logographic Chinese characters whose intrinsic features are retained even after reorganization. Due to this advantage, designers believe that such a re-organization process will not affect Chinese character recognition. However, not having an effect on recognition is not the same as not affecting the viewing process, especially when the character is so highly deconstructed that, along with the viewing process, the original intention of the design and its efficacy are both indirectly affected. Therefore, besides capturing the changes of character features, a good type designer should understand how characters are viewed. Past studies have found that character structure will affect character recognition, particularly for enclosed and non-enclosed characters whose differences are significant, although the interpretation of such differences remains open for discussion. This study explored the viewing process of Chinese characters with eye-tracking methods and calculated the concentration and saccadic amplitude of fixation in the viewing process in terms of the descriptive approach in a geographic information system, so as to investigate the differences among types of character modules with the spatial dispersion index. This study found that the overall vision when viewing enclosed structures is more concentrated than non-enclosed structures. |
Zheng Ma; Scott N. J. Watamaniuk; Stephen J. Heinen Illusory motion reveals velocity matching, not foveation, drives smooth pursuit of large objects Journal Article In: Journal of Vision, vol. 17, no. 12, pp. 1–14, 2017. @article{Ma2017b, When small objects move in a scene, we keep them foveated with smooth pursuit eye movements. Although large objects such as people and animals are common, it is nonetheless unknown how we pursue them since they cannot be foveated. It might be that the brain calculates an object's centroid, and then centers the eyes on it during pursuit as a foveation mechanism might. Alternatively, the brain merely matches the velocity by motion integration. We test these alternatives with an illusory motion stimulus that translates at a speed different from its retinal motion. The stimulus was a Gabor array that translated at a fixed velocity, with component Gabors that drifted with motion consistent or inconsistent with the translation. Velocity matching predicts different pursuit behaviors across drift conditions, while centroid matching predicts no difference. We also tested whether pursuit can segregate and ignore irrelevant local drifts when motion and centroid information are consistent by surrounding the Gabors with solid frames. Finally, observers judged the global translational speed of the Gabors to determine whether smooth pursuit and motion perception share mechanisms. We found that consistent Gabor motion enhanced pursuit gain while inconsistent, opposite motion diminished it, drawing the eyes away from the center of the stimulus and supporting a motion-based pursuit drive. Catch-up saccades tended to counter the position offset, directing the eyes opposite to the deviation caused by the pursuit gain change. Surrounding the Gabors with visible frames canceled both the gain increase and the compensatory saccades. Perceived speed was modulated analogous to pursuit gain. The results suggest that smooth pursuit of large stimuli depends on the magnitude of integrated retinal motion information, not its retinal location, and that the position system might be unnecessary for generating smooth velocity to large pursuit targets. |
Richard J. Macatee; Brian J. Albanese; Norman B. Schmidt; Jesse R. Cougle In: Behaviour Research and Therapy, vol. 90, pp. 96–110, 2017. @article{Macatee2017, Cognitive theories of anxiety psychopathology cite biased attention towards threat as a central vulnerability and maintaining factor. However, many studies have found threat bias indices to have poor reliability and have failed to observe the theorized relationship between threat bias and anxiety symptoms; this may be due to the non-unitary nature of threat bias and the influence of state-level variables on its expression. Accumulating data suggests that state anxious mood is important for the robust expression of threat bias and for relations to emerge between threat bias and symptoms, though this possibility has not been experimentally tested. Eye-tracking was used to assess multiple forms of threat bias (i.e., early vigilance, sustained attention, facilitated engagement, delayed disengagement) thought to be related to anxiety. A non-clinical sample (N = 165) was recruited to test the hypothesis that biased attention towards threat, but not dysphoric or positive emotional stimuli, during an anxious mood induction, but not at a pre-stress baseline, would prospectively predict greater worry symptoms on days in which more naturalistic stressors occurred. Results revealed the hypothesized moderation effect for sustained attention towards threat after the mood induction but not at baseline, though sustained attention towards dysphoric stimuli also moderated the effect of stressors on worry. Worry-relevant sustained attention towards negative emotional stimuli may be a partially mood-context dependent phenomenon. |
Richard J. Macatee; Brian J. Albanese; Norman B. Schmidt; Jesse R. Cougle In: Biological Psychology, vol. 123, pp. 83–93, 2017. @article{Macatee2017a, Low resting heart rate variability (HRV) is associated with a broad array of negative psychosocial outcomes. Recent theoretical explications of HRV suggest it is an autonomic marker of emotion regulation capacity, but limited research has examined its relationship with emotional information processing indices. The present study utilized eye-tracking methodology to test HRV's theorized role as a marker of emotion regulation capacity in a non-clinical sample. Attentional biases towards threatening, dysphoric, and positive emotional information as well as affective modulation of pupil size were assessed before and after a stress induction. Low resting HRV marginally predicted larger increases in attentional bias towards positive emotional stimuli from pre to post-stress induction and significantly predicted decreased pupil dilation to positive stimuli after the stress induction only; exploratory analyses suggested that this pattern might reflect an unsuccessful attempt at anxious mood repair. HRV was unrelated to negative emotional information processing. Findings are consistent with existing theories of HRV's psychological significance and suggest a specific association with altered positive emotional processing under acute stress. |
Andrew K. Mackenzie; Julie M. Harris A link between attentional function, effective eye movements, and driving ability Journal Article In: Journal of Experimental Psychology: Human Perception and Performance, vol. 43, no. 2, pp. 381–394, 2017. @article{Mackenzie2017, The misallocation of driver visual attention has been suggested as a major contributing factor to vehicle accidents. One possible reason is that the relatively high cognitive demands of driving limits the ability to efficiently allocate gaze. We present an experiment that explores the relationship between attentional function and visual performance when driving. Drivers performed two variations of a multiple object tracking task targeting aspects of cognition including sustained attention, dual-tasking, covert attention and visuomotor skill. They also drove a number of courses in a driving simulator. Eye movements were recorded throughout. We found that individuals who performed better in the cognitive tasks exhibited more effective eye movement strategies when driving, such as scanning more of the road, and they also exhibited better driving performance. We discuss the potential link between an individual's attentional function, effective eye movements and driving ability. We also discuss the use of a visuomotor task in assessing driving behaviour. |
Wayne E. MacKey; Clayton E. Curtis Distinct contributions by frontal and parietal cortices support working memory Journal Article In: Scientific Reports, vol. 7, pp. 6188, 2017. @article{MacKey2017, Although subregions of frontal and parietal cortex both contribute and coordinate to support working memory (WM) functions, their distinct contributions remain elusive. Here, we demonstrate that perturbations to topographically organized human frontal and parietal cortex during WM maintenance cause distinct but systematic distortions in WM. The nature of these distortions supports theories positing that parietal cortex mainly codes for retrospective sensory information, while frontal cortex codes for prospective action. |
Christopher R. Madan; Esther Fujiwara; Jeremy B. Caplan; Tobias Sommer Emotional arousal impairs association-memory: Roles of amygdala and hippocampus Journal Article In: NeuroImage, vol. 156, pp. 14–28, 2017. @article{Madan2017, Emotional arousal is well-known to enhance memory for individual items or events, whereas it can impair association memory. The neural mechanism of this association memory impairment by emotion is not known: In response to emotionally arousing information, amygdala activity may interfere with hippocampal associative encoding (e.g., via prefrontal cortex). Alternatively, emotional information may be harder to unitize, resulting in reduced availability of extra-hippocampal medial temporal lobe support for emotional than neutral associations. To test these opposing hypotheses, we compared neural processes underlying successful and unsuccessful encoding of emotional and neutral associations. Participants intentionally studied pairs of neutral and negative pictures (Experiments 1–3). We found reduced association-memory for negative pictures in all experiments, accompanied by item-memory increases in Experiment 2. High-resolution fMRI (Experiment 3) indicated that reductions in associative encoding of emotional information are localizable to an area in ventral-lateral amygdala, driven by attentional/salience effects in the central amygdala. Hippocampal activity was similar during both pair types, but a left hippocampal cluster related to successful encoding was observed only for negative pairs. Extra-hippocampal associative memory processes (e.g., unitization) were more effective for neutral than emotional materials. Our findings suggest that reduced emotional association memory is accompanied by increases in activity and functional coupling within the amygdala. This did not disrupt hippocampal association-memory processes, which indeed were critical for successful emotional association memory formation. |
Masoumeh Mahmoodi-Aghdam; Mohsen Dehghani; Mehrnoosh Ahmadi; Anahita Khorrami Banaraki; Ali Khatibi Chronic pain and selective attention to pain arousing daily activity pictures: Evidence from an eye tracking study Journal Article In: Basic and Clinical Neuroscience, vol. 8, no. 6, pp. 467–478, 2017. @article{MahmoodiAghdam2017, Introduction: According to the pain research literature, attentional bias for pain is the mechanism responsible for the development and maintenance of fear of pain in patients with chronic pain. However, there is still some debate about the exact mechanism and the role of faster engagement versus difficulty in disengagement in the development of attentional bias. Methods: To investigate attentional bias in patients with chronic pain, we used an eye-tracker with the pictures of pain-provoking activities and compared the results with an age-and gender-matched group of pain-free participants. In addition, other measures of pain-related cognition and pain severity ratings were included to assess their contribution to the attentional bias toward pain-related information. Results: Calculating the frequency of the first fixations showed that both groups fixated initially on pain-provoking pictures compared to neutral one. Calculating the speed of fixations showed that control participants were faster in fixating on neutral stimuli, but patients with pain were faster in fixating on pain-provoking pictures, indicating a relative vigilance for the pain-related stimuli among them. These patients reported that the intensity of pain in the previous week was positively correlated with the speed of their fixation on the painful stimuli. Conclusion: Although these results did not provide unequivocal support for the vigilance-avoidance hypothesis, they are generally consistent with the results of studies using eye tracking technology. Furthermore, our findings put a question over characterization of attentional biases in patients with chronic pain by simply relating that to difficulty in disengaging from pain-related stimuli. |
Manuela Malaspina; Andrea Albonico; Carlo Toneatto; Roberta Daini What do eye movements tell us about the visual perception of individuals with congenital prosopagnosia? Journal Article In: Neuropsychology, vol. 31, no. 5, pp. 546–563, 2017. @article{Malaspina2017, Objective: The lack of inversion effect for face recognition in congenital prosopagnosia (CP) is consistent with the hypothesis of a failure in holistic processing. However, although CPs' abnormal gaze behavior for upright faces has already been demonstrated, neither their scanning strategy for inverted faces, nor the possibility that their abnormal gaze behavior with upright faces is because of reasons other than the holistic deficit have been investigated yet. Method: We recorded the eye movements of a congenital prosopagnosic and a control group during the encoding of unknown faces, objects, and flowers. Two types of stimuli (faces and objects) were presented upright and inverted. Results: CPs explored upright and inverted faces in the same way (i.e., similar number of fixations of the same duration and similarly distributed), whereas controls increased the number of fixations and their duration during the presentation of inverted faces. By contrast, the 2 groups showed a similar inversion effect during the encoding of objects. Finally, CPs showed anomalous exploration of within-class objects (i.e., flowers) and impairment in subordinate-level object discrimination. Conclusions: Our results demonstrate that: (a) CPs use the same part-based strategy in encoding both upright and inverted faces, suggesting a possible interpretation of the lack of inversion effect in this population; (b) CPs' lack of inversion effect is face-specific and does not affect objects; (c) however, CPs' deficit seems not to be limited to faces, and to extend to individual-item recognition within a class. |
Leonardo Martin; Anthony Tapper; David A. Gonzalez; Michelle Leclerc; Ewa Niechwiej-Szwedo The effects of task-relevant saccadic eye movements performed during the encoding of a serial sequence on visuospatial memory performance Journal Article In: Experimental Brain Research, vol. 235, no. 5, pp. 1519–1529, 2017. @article{Martin2017, Visuospatial working memory (VSWM) is a set of cognitive processes used to encode, maintain and manipulate spatial information. One important feature of VSWM is that it has a limited capacity such that only few items can be actively stored and manipulated simultaneously. Given the limited capacity, it is important to determine the conditions that affect memory performance as this will improve our understanding of the architecture and function of VSWM. Previous studies have shown that VSWM is disrupted when task-irrelevant eye movements are performed during the maintenance phase; however, relatively fewer studies examined the role of eye movements performed during the encoding phase. On one hand, performing eye movements during the encoding phase could result in a stronger memory trace because the memory formation is reinforced by the activation of the motor system. On the other hand, performing eye movements to each target could disrupt the configural processing of the spatial array because the spatial representation has to be updated with each movement to maintain perceptual stability. Therefore, this work was conducted to examine whether task-relevant saccadic eye movements performed during the encoding phase of a visuospatial working memory task affect the recall of serially presented targets. Results from two experiments showed that average recall accuracy was significantly higher when the spatial array (set size ≥ 7) was encoded using a covert strategy-that is, while participants fixated on a central target, in comparison to an overt strategy-that is, while participants moved their eyes to fixate on each target. Furthermore, the improvement in accuracy was evident only for targets presented in the first half of the sequence, suggesting that the primacy effect is modulated by the presence of eye movements. We propose that executing saccades during encoding could interfere with the ability to use a chunking strategy or disrupt active visualization of the configuration. In conclusion, this is the first study to show that task-relevant saccadic eye movements performed during encoding may actually reduce the spatial span of VSWM. These results extend the current knowledge about the role of eye movements in VSWM, and have implications for future studies investigating the VSWM. |
Jun Maruta; Lisa A. Spielman; Irene D. Tseretopoulos; Adrienne Hezghia; Jamshid Ghajar Possible medication-resistant deficits in adult ADHD Journal Article In: Journal of Attention Disorders, vol. 21, no. 14, pp. 1169–1179, 2017. @article{Maruta2017b, OBJECTIVE: The nature of ADHD, especially in adulthood, is not well-understood. Therefore, we explored subcomponents of attention in adult ADHD. METHOD: Twenty-three adults with ADHD were tested on neurocognitive and visual tracking performance both while on their regular prescription stimulant medication and while abstaining from the medication for 1 day. Pairwise comparisons to 46 two-for-one matched normal controls were made to detect medication-resistant effects of ADHD, and within-participant comparisons were made to detect medication-sensitive effects in patients. RESULTS: Even when on medication, patients performed more poorly than controls on a spatial working memory task, and on visual tracking and simple reaction time tasks immediately following other attention-demanding tasks. Patients' visual tracking performance degraded while off-medication in a manner consistent with reduced vigilance. CONCLUSION: There may be persistent cognitive impairments in adult ADHD despite medication. In addition, the benefit of stimulants seems reduced under cognitive fatigue. |
Anna Marzecová; Andreas Widmann; Iria SanMiguel; Sonja A. Kotz; Erich Schröger Interrelation of attention and prediction in visual processing: Effects of task-relevance and stimulus probability Journal Article In: Biological Psychology, vol. 125, pp. 76–90, 2017. @article{Marzecova2017, The potentially interactive influence of attention and prediction was investigated by measuring event-related potentials (ERPs) in a spatial cueing task with attention (task-relevant) and prediction (probabilistic) cues. We identified distinct processing stages of this interactive influence. Firstly, in line with the attentional gain hypothesis, a larger amplitude response of the contralateral N1, and Nd1 for attended gratings was observed. Secondly, conforming to the attenuation-by-prediction hypothesis, a smaller negativity in the time window directly following the peak of the N1 component for predicted compared to unpredicted gratings was observed. In line with the hypothesis that attention and prediction interface, unpredicted/unattended stimuli elicited a larger negativity at central-parietal sites, presumably reflecting an increased prediction error signal. Thirdly, larger P3 responses to unpredicted stimuli pointed to the updating of an internal model. Attention and prediction can be considered as differentiated mechanisms that may interact at different processing stages to optimise perception. |
Nicolas Y. Masse; Jonathan M. Hodnefield; David J. Freedman Mnemonic encoding and cortical organization in parietal and prefrontal cortices Journal Article In: Journal of Neuroscience, vol. 37, no. 25, pp. 6098–6112, 2017. @article{Masse2017, Persistent activity within the frontoparietal network is consistently observed during tasks that require working memory. However, the neural circuit mechanisms underlying persistent neuronal encoding within this network remain unresolved. Here, we ask how neural circuits support persistent activity by examining population recordings from posterior parietal (PPC) and prefrontal (PFC) cortices in two male monkeys that performed spatial and motion direction-based tasks that required working memory. While spatially selective persistent activity was observed in both areas, robust selective persistent activity for motion direction was only observed in PFC. Crucially, we find that this difference between mnemonic encoding in PPC and PFC is associated with the presence offunctional clustering: PPC and PFC neurons up to ~700 μm apart preferred similar spatial locations, and PFC neurons up to ~700 μm apart preferred similar motion directions. In contrast, motion-direction tuning similarity between nearby PPC neurons was much weaker and decayed rapidly beyond ~200 μm. We also observed a similar association between persistent activity and functional clustering in trained recurrent neural network models embedded with a columnar topology. These results suggest that functional clustering facilitates mnemonic encoding of sensory information. |
Nicolas Masson; Mauro Pesenti; Valérie Dormal Impact of optokinetic stimulation on mental arithmetic Journal Article In: Psychological Research, vol. 81, no. 4, pp. 840–849, 2017. @article{Masson2017, Solving arithmetic problems has been shown to induce shifts of spatial attention, subtraction problems orienting attention to the left side, and addition problems to the right side of space. At the neurofunctional level, the activations elicited by the solving of arithmetical problems resemble those elicited by horizontal eye movements. Whether overt orientation of attention (i.e., eye movements) can be linked to the solving procedure is, however, still under debate. In the present study, we used optokinetic stimulation (OKS) to trigger automatic eye movements to orient participants' overt attention to the right or to the left of their visual field while they were solving addition or subtraction problems. The results show that, in comparison to leftward OKS and a control condition, rightward OKS facilitates the solving of addition problems that necessitate a carrying procedure. Subtraction solving was unaffected by leftward or rightward OKS. These results converge with previous findings to show that attentional shifts are functionally related to mental arithmetic processing |
James Mathew; Alexandre Eusebio; Frederic R. Danion Limited contribution of primary motor cortex in eye-hand coordination: A TMS study Journal Article In: Journal of Neuroscience, vol. 37, no. 40, pp. 9730 –9740, 2017. @article{Mathew2017, The ability to track a moving target with the eye is substantially improved when the target is self-moved compared with when it is moved by an external agent. To account for this observation, it has been postulated that the oculomotor system has access to hand efference copy, thereby allowing to predict the motion of the visual target. Along this scheme, we tested the effect of transcranial magnetic stimulation (TMS) over the hand area of the primary motor cortex (M1) when human participants (50% females) are asked to track with their eyes a visual target whose horizontal motion is driven by their grip force. We reasoned that, if the output of M1 is used by the oculomotor system to keep track of the target, on top of inducing short latency disturbance of grip force, single-pulse TMS should also quickly disrupt ongoing eye motion. For comparison purposes, the effect of TMS over M1 was monitored when subjects tracked an externally moved target (while keeping their hand at rest or not). In both cases, results showed no alterations in smooth pursuit, meaning that its velocity was unaffected within the 25-125 ms epoch that followed TMS. Overall, our results imply that the output of M1 has limited contribution in driving the eye motion during our eye-hand coordination task. This study suggests that, if hand motor signals are accessed by the oculomotor system, this is upstream of M1. |
Gavin R. Price; Eric D. Wilkey; Darren J. Yeo Eye-movement patterns during nonsymbolic and symbolic numerical magnitude comparison and their relation to math calculation skills Journal Article In: Acta Psychologica, vol. 176, pp. 47–57, 2017. @article{Price2017, A growing body of research suggests that the processing of nonsymbolic (e.g. sets of dots) and symbolic (e.g. Arabic digits) numerical magnitudes serves as a foundation for the development of math competence. Performance on magnitude comparison tasks is thought to reflect the precision of a shared cognitive representation, as evidence by the presence of a numerical ratio effect for both formats. However, little is known regarding how visuo-perceptual processes are related to the numerical ratio effect, whether they are shared across numerical formats, and whether they relate to math competence independently of performance outcomes. The present study investigates these questions in a sample of typically developing adults. Our results reveal a pattern of associations between eye-movement measures, but not their ratio effects, across formats. This suggests that ratio-specific visuo-perceptual processing during magnitude processing is different across nonsymbolic and symbolic formats. Furthermore, eye movements are related to math performance only during symbolic comparison, supporting a growing body of literature suggesting symbolic number processing is more strongly related to math outcomes than nonsymbolic magnitude processing. Finally, eye-movement patterns, specifically fixation dwell time, continue to be negatively related to math performance after controlling for task performance (i.e. error rate and reaction time) and domain general cognitive abilities (IQ), suggesting that fluent visual processing of Arabic digits plays a unique and important role in linking symbolic number processing to formal math abilities. |
Maria Solé Puig; August Romeo; Jose Cañete Crespillo; Hans Supèr Eye vergence responses during a visual memory task Journal Article In: NeuroReport, vol. 28, no. 3, pp. 123–127, 2017. @article{Puig2017, In a previous report it was shown that covertly attending visual stimuli produce small convergence of the eyes, and that visual stimuli can give rise to different modulations of the angle of eye vergence, depending on their power to capture attention. Working memory is highly dependent on attention. Therefore, in this study we assessed vergence responses in a memory task. Participants scanned a set of 8 or 12 images for 10 s, and thereafter were presented with a series of single images. One half were repeat images - that is, they belonged to the initial set - and the other half were novel images. Participants were asked to indicate whether or not the images were included in the initial image set. We observed that eyes converge during scanning the set of images and during the presentation of the single images. The convergence was stronger for remembered images compared with the vergence for nonremembered images. Modulation in pupil size did not correspond to behavioural responses. The correspondence between vergence and coding/retrieval processes of memory strengthen the idea of a role for vergence in attention processing of visual information. |
Erdem Pulcu; Michael Browning Affective bias as a rational response to the statistics of rewards and punishments Journal Article In: eLife, vol. 6, pp. 1–15, 2017. @article{Pulcu2017, Affective bias, the tendency to differentially prioritise the processing of negative relative to positive events, is commonly observed in clinical and non-clinical populations. However, why such biases develop is not known. Using a computational framework, we investigated whether affective biases may reflect individuals' estimates of the information content of negative relative to positive events. During a reinforcement learning task, the information content of positive and negative outcomes was manipulated independently by varying the volatility of their occurrence. Human participants altered the learning rates used for the outcomes selectively, preferentially learning from the most informative. This behaviour was associated with activity of the central norepinephrine system, estimated using pupilometry, for loss outcomes. Humans maintain independent estimates of the information content of distinct positive and negative outcomes which may bias their processing of affective events. Normalising affective biases using computationally inspired interventions may represent a novel approach to treatment development. |
Michael Puntiroli; C. Tandonnet; D. Kerzel; S. Born Race to accumulate evidence for few and many saccade alternatives: An exception to speed–accuracy trade-off Journal Article In: Experimental Brain Research, vol. 235, no. 2, pp. 507–515, 2017. @article{Puntiroli2017, Hick's law states that increasing the number of response alternatives increases reaction time. Lawrence and colleagues report an exception to the law, whereby more alternatives lead to shorter saccadic reaction times (SRTs). Usher and McClelland (Psychol Rev 108(3):550–592. doi:10.1037/0033-295X.108.3.550, 2001) predict such an anti-Hick's effect when accuracy is not prioritized in a task, which should result in higher error rates with more response alternatives, and in turn to a shorter right tail of the SRT distribution. In the current study, we aim to replicate the original controversial findings and we compare them to these predictions by examining error rates and SRT distributions. Two experiments were conducted where participants made rapid eye movements to one of few or many alternatives. In Experiment 1, the saccade target was an onset and participants started either with few or many possible target locations and then alternated between conditions. An anti-Hick's effect emerged only when participants had started with a small set-size block. In Experiment 2, placeholders were displayed at the possible target locations and independent groups were used. A reliable anti-Hick's effect in SRTs was observed. However, results did not meet the stated predictions: anticipations and false direction errors were never more frequent when the set size was larger and SRT differences between the two set-size conditions were not more pronounced at the slower end of the distributions. In line with Lawrence and colleagues, we speculate that initial motor preparation, and the subsequent inhibition to counteract a premature response, may induce the anti-Hick's effect. |
Jason Rajsic; Henry Liu; Jay Pratt Eye movements can cause item-specific visual recognition advantages Journal Article In: Visual Cognition, vol. 25, no. 9-10, pp. 903–912, 2017. @article{Rajsic2017a, Prior research suggests that spontaneous saccades localized towards blank regions of space during memory storage and recall improve memory for items at the saccade locations. In the present study, we examined whether a recognition advantage can be observed when a single, exogenously directed saccade occurs during memory maintenance. We manipulated whether participants made a saccade to an item's previous location or maintained fixation, as well as whether tested items reappeared in their original location or not. The results of three experiments showed that visual recognition was better after a saccade to the location of a probed object than after no saccade or after a saccade to the location of a non-probed object, so long as saccades went to the to-be-tested location more often than chance. Taken together, our findings demonstrate that eye movements can elicit an item-specific recognition advantage in visual working memory. |
Jason Rajsic; Daryl E. Wilson; Jay Pratt The price of information: Increased inspection costs reduce the confirmation bias in visual search Journal Article In: Quarterly Journal of Experimental Psychology, vol. 71, no. 4, pp. 832 –849, 2017. @article{Rajsic2017, In visual search, there is a confirmation bias such that attention is biased towards stimuli that match a target template, which has been attributed to covert costs of updating the templates that guide search [Rajsic, Wilson, & Pratt, 2015. Confirmation bias in visual search. Journal of Experimental Psychology: Human Perception and Performance. Advance online publication. doi:10.1037/xhp0000090]. In order to provide direct evidence for this speculation, the present study increased the cost of inspections in search by using gaze- and mouse-contingent searches, which restrict the manner in which information in search displays can be accrued, and incur additional motor costs (in the case of mouse-contingent searches). In a fourth experiment, we rhythmically mask elements in the search display to induce temporal inspection costs. Our results indicated that confirmation bias is indeed attenuated when inspection costs are increased. We conclude that confirmat ion bias results from the low-cost strategy of matching information to a single, concrete visual template, and that more sophisticated guidance strategies will be used when sufficiently beneficial. This demonstrates that search guidance itself comes at a cost, and that the form of guidance adopted in a given search depends on a comparison between guidance costs and the expected benefits of their implementation. |
Ileana Ratiu; Michael C. Hout; Stephen C. Walenchok; Tamiko Azuma; Stephen D. Goldinger Comparing visual search and eye movements in bilinguals and monolinguals Journal Article In: Attention, Perception, and Psychophysics, vol. 79, no. 6, pp. 1695–1725, 2017. @article{Ratiu2017, Recent research has suggested that bilinguals show advantages over monolinguals in visual search tasks, although these findings have been derived from global behavioral measures of accuracy and response times. In the present study we sought to explore the bilingual advantage by using more sensitive eyetracking techniques across three visual search experiments. These spatially and temporally fine-grained measures allowed us to carefully investigate any nuanced attentional differences between bilinguals and monolinguals. Bilingual and monolingual participants completed visual search tasks that varied in difficulty. The experiments required participants to make careful discriminations in order to detect target Landolt Cs among similar distractors. In Experiment 1, participants performed both feature and conjunction search. In Experiments 2 and 3, participants performed visual search while making different types of speeded discriminations, after either locating the target or mentally updating a constantly changing target. The results across all experiments revealed that bilinguals and monolinguals were equally efficient at guiding attention and generating responses. These findings suggest that the bilingual advantage does not reflect a general benefit in attentional guidance, but could reflect more efficient guidance only under specific task demands. |
Michael Papinutto; Roberto Caldara The Facespan—the perceptual span for face recognition Journal Article In: Journal of Vision, vol. 17, no. 5, pp. 1–12, 2017. @article{Papinutto2017, In reading, the perceptual span is a well-established concept that refers to the amount of information that can be read in a single fixation. Surprisingly, despite extensive empirical interest in determining the perceptual strategies deployed to process faces and an ongoing debate regarding the factors or mechanism(s) underlying efficient face processing, the perceptual span for faces—the Facespan—remains undetermined. To address this issue, we applied the gaze-contingent Spotlight technique implemented in an old-new face recognition paradigm. This procedure allowed us to parametrically vary the amount of facial information available at a fixated location in order to determine the minimal aperture size at which face recognition performance plateaus. As expected, accuracy increased nonlinearly with spotlight size apertures. Analyses of Structural Similarity comparing the available information during spotlight and natural viewing conditions indicate that the Facespan—the minimum spatial extent of preserved facial information leading to comparable performance as in natural viewing—encompasses 78 of visual angle in our viewing conditions (size of the face stimulus: 15.68; viewing distance: 70 cm), which represents 45% of the face. The present findings provide a benchmark for future investigations that will address if and how the Facespan is modulated by factors such as cultural, developmental, idiosyncratic, or task-related differences. |
Jacob M. Paul; Robert A. Reeve; Jason D. Forte Taking a(c)count of eye movements: Multiple mechanisms underlie fixations during enumeration Journal Article In: Journal of Vision, vol. 17, no. 3, pp. 1–14, 2017. @article{Paul2017, We habitually move our eyes when we enumerate sets of objects. It remains unclear whether saccades are directed for numerosity processing as distinct from object-oriented visual processing (e.g., object saliency, scanning heuristics). Here we investigated the extent to which enumeration eye movements are contingent upon the location of objects in an array, and whether fixation patterns vary with enumeration demands. Twenty adults enumerated random dot arrays twice: first to report the set cardinality and second to judge the perceived number of subsets.We manipulated the spatial location of dots by presenting arrays at 08,908, 1808, and 2708 orientations. Participants required a similar time to enumerate the set or the perceived number of subsets in the same array. Fixation patterns were systematically shifted in the direction of array rotation, and distributed across similar locations when the same array was shown on multiple occasions.We modeled fixation patterns and dot saliency using a simple filtering model and show participants judged groups of dots in close proximity (28– 2.58 visual angle) as distinct subsets. Modeling results are consistent with the suggestion that enumeration involves visual grouping mechanisms based on object saliency, and specific enumeration demands affect spatial distribution of fixations. Our findings highlight the importance of set computation, rather than object processing per se, for models of numerosity processing. |
Chad Peltier; Mark W. Becker Eye movement feedback fails to improve visual search performance Journal Article In: Cognitive Research: Principles and Implications, vol. 2, no. 47, pp. 1–8, 2017. @article{Peltier2017a, Many real-world searches (e.g., radiology and baggage screening) have rare targets. When targets are rare, observers perform rapid, incomplete searches, leading to higher miss rates. To improve search for rare (10% prevalence) targets, we provided eye movement feedback (EMF) to observers during their searches. Although the nature of the EMF varied across experiments, each method informed observers about the regions of the display that had not yet been inspected. We hypothesized that feedback would help guide attention to unsearched areas and increase the proportion of the display searched before making a target-absent response, thereby increasing accuracy. An eye tracker was used to mark fixated areas by either removing a semiopaque gray overlay (Experiments 1 and 4) as portions of the display were fixated or by adding the overlay once the eye left a segment of the image (Experiments 2 and 4). Experiment 3 provided automated EMF, such that a new region was uncovered every 540 milliseconds. Across experiments, we varied whether people searched for "Waldo" in images from "Where's Waldo?" search books or searched for a T among offset Ls. We found weak evidence that EMF improves accuracy in Experiment 1. However, in the remaining experiments, EMF had no effect (Experiment 4), or even reduced accuracy (Experiments 2 and 3). We conclude that the one positive result we found is likely a Type I error and that the EMF method that we used is unlikely to improve visual search performance. |
Chad Peltier; Mark W. Becker Working memory capacity predicts selection and identification errors in visual search Journal Article In: Perception, vol. 46, no. 1, pp. 109–115, 2017. @article{Peltier2017b, As public safety relies on the ability of professionals, such as radiologists and baggage screeners, to detect rare targets, it could be useful to identify predictors of visual search performance. Schwark, Sandry, and Dolgov found that working memory capacity (WMC) predicts hit rate and reaction time in low prevalence searches. This link was attributed to higher WMC individuals exhibiting a higher quitting threshold and increasing the probability of finding the target before terminating search in low prevalence search. These conclusions were limited based on the methods; without eye tracking, the researchers could not differentiate between an increase in accuracy due to fewer identification errors (failing to identify a fixated target), selection errors (failing to fixate a target), or a combination of both. Here, we measure WMC and correlate it with reaction time and accuracy in a visual search task. We replicate the finding that WMC predicts reaction time and hit rate. However, our analysis shows that it does so through both a reduction in selection and identification errors. The correlation between WMC and selection errors is attributable to increased quitting thresholds in those with high WMC. The correlation between WMC and identification errors is less clear, though potentially attributable to increased item inspection times in those with higher WMC. In addition, unlike Schwark and coworkers, we find that these WMC effects are fairly consistent across prevalence rates rather than being specific to low-prevalence searches. |
Chad Peltier; Mark W. Becker Target-present guessing as a function of target prevalence and accumulated information in visual search Journal Article In: Attention, Perception, and Psychophysics, vol. 79, no. 4, pp. 1064–1069, 2017. @article{Peltier2017, Target prevalence influences visual search behav- ior. At low target prevalence, miss rates are high and false alarms are low, while the opposite is true at high prevalence. Several models of search aimto describe search behavior, one of which has been specifically intended to model search at varying prevalence levels. The multiple decision model (Wolfe & Van Wert, Current Biology, 20(2), 121-–124, 2010) posits that all searches that end before the observer detects a target result in a target-absent response. However, researchers have found very high false alarms in high- prevalence searches, suggesting that prevalence rates may be used as a source of information to make Beducated guesses^ after search termination. Here, we further examine the ability for prevalence level and knowledge gained during visual search to influence guessing rates.We manipulate target prev- alence and the amount of information that an observer accu- mulates about a search display prior to making a response to test if these sources of evidence are used to inform target present guess rates.We find that observers use both informa- tion about target prevalence rates and information about the proportion of the array inspected prior to making a response allowing them to make an informed and statistically driven guess about the target'spresence. |
Maxine Perrin; Manon Robillard; Annie Roy-Charland Observing eye movements and the influence of cognition during a symbol search task: A comparison across three age groups Journal Article In: Augmentative and Alternative Communication, vol. 33, no. 4, pp. 249–259, 2017. @article{Perrin2017, This study examined eye movements during a visual search task as well as cognitive abilities within three age groups. The aim was to explore scanning patterns across symbol grids and to better understand the impact of symbol location in AAC displays on speed and accuracy of symbol selection. For the study, 60 students were asked to locate a series of symbols on 16 cell grids. The EyeLink 1000 was used to measure eye movements, accuracy, and response time. Accuracy was high across all cells. Participants had faster response times, longer fixations, and more frequent fixations on symbols located in the middle of the grid. Group comparisons revealed significant differences for accuracy and reaction times. The Leiter-R was used to evaluate cognitive abilities. Sustained attention and cognitive flexibility scores predicted the participants’ reaction time and accuracy in symbol selection. Findings suggest that symbol location within AAC devices and individuals’ cognitive abilities influence the speed and accuracy of retrieving symbols. |
Anders Petersen; Annemarie Hilkjær Petersen; Claus Bundesen; Signe Vangkilde; Thomas Habekost The effect of phasic auditory alerting on visual perception Journal Article In: Cognition, vol. 165, pp. 73–81, 2017. @article{Petersen2017, Phasic alertness refers to a short-lived change in the preparatory state of the cognitive system following an alerting signal. In the present study, we examined the effect of phasic auditory alerting on distinct perceptual processes, unconfounded by motor components. We combined an alerting/no-alerting design with a pure accuracy-based single-letter recognition task. Computational modeling based on Bundesen's Theory of Visual Attention was used to examine the effect of phasic alertness on visual processing speed and threshold of conscious perception. Results show that phasic auditory alertness affects visual perception by increasing the visual processing speed and lowering the threshold of conscious perception (Experiment 1). By manipulating the intensity of the alerting cue, we further observed a positive relationship between alerting intensity and processing speed, which was not seen for the threshold of conscious perception (Experiment 2). This was replicated in a third experiment, in which pupil size was measured as a physiological marker of alertness. Results revealed that the increase in processing speed was accompanied by an increase in pupil size, substantiating the link between alertness and processing speed (Experiment 3). The implications of these results are discussed in relation to a newly developed mathematical model of the relationship between levels of alertness and the speed with which humans process visual information. |
Olivia M. Maynard; Jonathan C. W. Brooks; Marcus R. Munafò; Ute Leonards Neural mechanisms underlying visual attention to health warnings on branded and plain cigarette packs Journal Article In: Addiction, vol. 112, no. 4, pp. 662–672, 2017. @article{Maynard2017, Aims: To (1) test if activation in brain regions related to reward (nucleus accumbens) and emotion (amygdala) differ when branded and plain packs of cigarettes are viewed, (2) test whether these activation patterns differ by smoking status and (3) examine whether activation patterns differ as a function of visual attention to health warning labels on cigarette packs. Design: Cross-sectional observational study combining functional magnetic resonance imaging (fMRI) with eye-tracking. Non-smokers, weekly smokers and daily smokers performed a memory task on branded and plain cigarette packs with pictorial health warnings presented in an event-related design. Setting: Clinical Research and Imaging Centre, University of Bristol, UK. Participants: Non-smokers, weekly smokers and daily smokers (n = 72) were tested. After exclusions, data from 19 non-smokers, 19 weekly smokers and 20 daily smokers were analysed. Measurements: Brain activity was assessed in whole brain analyses and in pre-specified masked analyses in the amygdala and nucleus accumbens. On-line eye-tracking during scanning recorded visual attention to health warnings. Findings: There was no evidence for a main effect of pack type or smoking status in either the nucleus accumbens or amygdala, and this was unchanged when taking account of visual attention to health warnings. However, there was evidence for an interaction, such that we observed increased activation in the right amygdala when viewing branded as compared with plain packs among weekly smokers (P = 0.003). When taking into account visual attention to health warnings, we observed higher levels of activation in the visual cortex in response to plain packaging compared with branded packaging of cigarettes (P = 0.020). Conclusions: Based on functional magnetic resonance imaging and eye-tracking data, health warnings appear to be more salient on ‘plain' cigarette packs than branded packs. |
Daniel R. McCloy; Bonnie K. Lau; Eric D. Larson; Katherine A. I. Pratt; Adrian K. C. Lee Pupillometry shows the effort of auditory attention switching Journal Article In: The Journal of the Acoustical Society of America, vol. 141, no. 4, pp. 2440–2451, 2017. @article{McCloy2017, © 2017 Acoustical Society of America. Successful speech communication often requires selective attention to a target stream amidst competing sounds, as well as the ability to switch attention among multiple interlocutors. However, auditory attention switching negatively affects both target detection accuracy and reaction time, suggesting that attention switches carry a cognitive cost. Pupillometry is one method of assessing mental effort or cognitive load. Two experiments were conducted to determine whether the effort associated with attention switches is detectable in the pupillary response. In both experiments, pupil dilation, target detection sensitivity, and reaction time were measured; the task required listeners to either maintain or switch attention between two concurrent speech streams. Secondary manipulations explored whether switch-related effort would increase when auditory streaming was harder. In experiment 1, spatially distinct stimuli were degraded by simulating reverberation (compromising across-time streaming cues), and target-masker talker gender match was also varied. In experiment 2, diotic streams separable by talker voice quality and pitch were degraded by noise vocoding, and the time alloted for mid-trial attention switching was varied. All trial manipulations had some effect on target detection sensitivity and/or reaction time; however, only the attention-switching manipulation affected the pupillary response: greater dilation was observed in trials requiring switching attention between talkers. |
Jessica McKnight; Jason C. Coronel Evaluating scientists as sources of science information: Evidence from eye movements Journal Article In: Journal of Communication, vol. 67, no. 4, pp. 565–585, 2017. @article{McKnight2017, In the new information environment, individuals can be exposed to different scientists who disseminate information on scientific topics which may or may not be in the scientist's area of expertise. The current study investigates people's ability to evaluate finer, but critical, distinctions in expertise. We use eye movements and self-report measures to determine the extent to which individuals retrieve, from their memories, professional facts about scientists that signal their area of expertise. Our results suggest that individuals can discern expert from nonexpert scientist sources but self-report measures may not accurately reflect this phenomenon, thus highlighting the value of a converging methods approach. We discuss the theoretical and practical implications of these findings. |
Eugene McSorley; Jayne Morriss What you see is what you want to see: Motivationally relevant stimuli can interrupt current resource allocation Journal Article In: Cognition and Emotion, vol. 31, no. 1, pp. 168–174, 2017. @article{McSorley2017a, Arousing stimuli, either threat-related or pleasant, may be selected for priority at different stages within the processing stream. Here we examine the pattern of processing for non-task-relevant threatening (spiders: arousing to some) and pleasant stimuli (babies or chocolate: arousing to all) by recording the gaze of a spider Fearful and Non-fearful group while they performed a simple "follow the cross" task. There was no difference in first saccade latencies. Saccade trajectories showed a general hypervigilance for all stimuli in the Fearful group. Saccade landing positions corresponded to what each group would find arousing, such that the Fearful group deviated towards both types of images whereas the Non-fearful group deviated towards pleasant images. Secondary corrective saccade latencies away from threat-related stimuli were longer for the Fearful group (difficulty in disengaging) compared with the Non-fearful group. These results suggest that attentional biases towards arousing stimuli may occur at different processing stages. |
Eugene McSorley; Jayne Morriss; Carien M. Reekum Eye spy with my little eye: Motivational relevance of visual stimuli guide eye-movements at different processing stages Journal Article In: Biological Psychology, vol. 123, pp. 8–14, 2017. @article{McSorley2017, Visual stimuli may be selected for priority at different stages within the processing stream, depending on how motivationally relevant they are to the perceiver. Here we examine the extent to which individual differences in motivational relevance of task-irrelevant images (spider, crash, baby, food and neutral) guide eye-movements to a simple “follow the cross” task in 96 participants. We found affective images vs. neutral images to be generally more distracting, as shown by faster first saccade latencies and greater deviation in the final landing position from the target cross. The most arousing images (spider and food), compared to neutral images, showed the largest trajectory deviations of the first saccade. Fear of spiders specifically predicted greater deviation in the final landing position on spider images. These results suggest that attentional biases towards arousing and motivationally relevant stimuli may occur at different processing stages. |
Annegret Meermeier; Svenja Gremmler; Kerstin Richert; Til Eckermann; Markus Lappe The reward of seeing: Different types of visual reward and their ability to modify oculomotor learning Journal Article In: Journal of Vision, vol. 17, no. 12, pp. 1–13, 2017. @article{Meermeier2017a, Saccadic adaptation is an oculomotor learning process that maintains the accuracy of eye movements to ensure effective perception of the environment. Although saccadic adaptation is commonly considered an automatic and low-level motor calibration in the cerebellum, we recently found that strength of adaptation is influenced by the visual content of the target: pictures of humans produced stronger adaptation than noise stimuli. This suggests that meaningful images may be considered rewarding or valuable in oculomotor learning. Here we report three experiments that establish the boundaries of this effect. In the first, we tested whether stimuli that were associated with high and low value following long term self-administered reinforcement learning produce stronger adaptation. Twenty-eight expert gamers participated in two sessions of adaptation to game-related high-and low-reward stimuli, but revealed no difference in saccadic adaptation (Bayes Factor 01 ¼ 5.49). In the second experiment, we tested whether cognitive (literate) meaning could induce stronger adaptation by comparing targets consisting of words and nonwords. The results of twenty subjects revealed no difference in adaptation strength (Bayes Factor 01 ¼ 3.21). The third experiment compared images of human figures to noise patterns for reactive saccades. Twenty-two subjects adapted significantly more toward images of human figures in comparison to noise (p , 0.001). We conclude that only primary (human vs. noise), but not secondary, reinforcement affects saccadic adaptation (words vs. nonwords, high-vs. low-value video game images). |
Geoffrey Megardon; Casimir J. H. Ludwig; Petroc Sumner Trajectory curvature in saccade sequences: Spatiotopic influences vs. residual motor activity Journal Article In: Journal of Neurophysiology, vol. 118, no. 2, pp. 1310–1320, 2017. @article{Megardon2017, When decisions drive saccadic eye movements, traces of the decision process can be inferred from the movement trajectories. For example, saccades can curve away from distractor stimuli, which was thought to reflect cortical inhibition biasing activity in the superior colliculus. Recent neurophysiological work does not support this theory, and two recent models have replaced top-down inhibition with lateral interactions in the superior colliculus or neural fatigue in the brainstem saccadic burst generator. All current models operate in retinotopic coordinates and are based on single saccade paradigms. To extend these models to sequences of saccades, we assessed whether and how saccade curvature depends on previously fixated locations and the direction of previous saccades. With a two-saccade paradigm, we first demonstrated that second saccades curved away from the initial fixation stimulus. Furthermore, by varying the time from fixation offset and the intersaccadic duration, we distinguished the extent of curvature originating from the spatiotopic representation of the previous fixation location or residual motor activity of the previous saccade. Results suggest that both factors drive curvature, and we discuss how these effects could be implemented in current models. In particular, we propose that the collicular retinotopic maps receive an excitatory spatiotopic update from the lateral interparial region. |
Thomas Meindertsma; Niels A. Kloosterman; Guido Nolte; Andreas K. Engel; Tobias H. Donner Multiple transient signals in human visual cortex associated with an elementary decision Journal Article In: Journal of Neuroscience, vol. 37, no. 23, pp. 5744–5757, 2017. @article{Meindertsma2017, The cerebral cortex continuously undergoes changes in its state, which are manifested in transient modulations of the cortical power spectrum. Cortical state changes also occur at full wakefulness and during rapid cognitive acts, such as perceptual decisions. Previous studies found a global modulation of beta-band (12–30 Hz) activity in human and monkey visual cortex during an elementary visual decision: reporting the appearance or disappearance of salient visual targets surrounded by a distractor. The previous studies disentangled neither the motor action associated with behavioral report nor other secondary processes, such as arousal, from perceptual decision processing per se. Here, we used magnetoencephalography in humans to pinpoint the factors underlying the beta-band modulation.We found that disappearances of a salient target were associated with beta-band suppression, and target reappearances with beta-band enhancement. This was true for both overt behavioral reports (immediate button presses) and silent counting of the perceptual events. This finding indicates that the beta-band modulation was unrelated to the execution of the motor act associated with a behavioral report of the perceptual decision. Further, changes in pupil-linked arousal, fixational eye movements, or gamma-band responses were not necessary for the beta-band modulation. Together, our results suggest that the beta-band modulation was a top-down signal associated with the process of converting graded perceptual signals into a categorical format underlying flexible behavior. This signal may have been fed back from brain regions involved in decision processing to visual cortex, thus enforcing a “decision-consistent” cortical state. |
Diego Mendoza-Halliday; Julio C. Martinez-Trujillo Neuronal population coding of perceived and memorized visual features in the lateral prefrontal cortex Journal Article In: Nature Communications, vol. 8, pp. 15471, 2017. @article{MendozaHalliday2017, The primate lateral prefrontal cortex (LPFC) encodes visual stimulus features while they are perceived and while they are maintained in working memory. However, it remains unclear whether perceived and memorized features are encoded by the same or different neurons and population activity patterns. Here we record LPFC neuronal activity while monkeys perceive the motion direction of a stimulus that remains visually available, or memorize the direction if the stimulus disappears. We find neurons with a wide variety of combinations of coding strength for perceived and memorized directions: some neurons encode both to similar degrees while others preferentially or exclusively encode either one. Reading out the combined activity of all neurons, a machine-learning algorithm reliably decode the motion direction and determine whether it is perceived or memorized. Our results indicate that a functionally diverse population of LPFC neurons provides a substrate for discriminating between perceptual and mnemonic representations of visual features. |
Céline Paeye; Thérèse Collins; Patrick Cavanagh Transsaccadic perceptual fusion Journal Article In: Journal of Vision, vol. 17, no. 1, pp. 1–11, 2017. @article{Paeye2017, Transsaccadic perceptual fusion is the integration of pre- and postsaccadic images into a single percept aligned in spatial coordinates. Several early studies reported an absence of transsaccadic fusion between dissimilar patterns, effectively stopping research on this question for three decades. We have now corrected two problematic aspects of these earlier studies and find robust evidence for transsaccadic perceptual fusion. First, we used simple pre- and postsaccadic targets, (|, ) for which spatial alignment is not critical. Second, we reduced the contrast of the postsaccadic stimulus, so that it would not suppress fusion. Participants reported seeing a superposition of the pre- and postsaccadic targets on 67% of trials. Importantly, we obtained similar results when the two stimuli were presented without an intervening eye movement, suggesting the existence of a general fusion mechanism. Directional biases in the saccade condition suggest that remapping might be the mechanism realigning the pre- and postsaccadic locations. Remapping may thus not only predict where targets will be located after a saccade but may also guide content, predicting what targets will look like. However, the constraints on the appearance of the fused percept suggest that it plays, at best, a limited role in visual stability across saccades. |
Rebecca E. Paladini; René M. Müri; Jurka Meichtry; Tobias Nef; Fred W. Mast; Urs P. Mosimann; Thomas Nyffeler; Dario Cazzoli The influence of alertness on the spatial deployment of visual attention is mediated by the excitability of the posterior parietal cortices Journal Article In: Cerebral Cortex, vol. 27, no. 1, pp. 233–243, 2017. @article{Paladini2017, With a reduced level of alertness, healthy individuals typically show a rightward shift when deploying visual attention in space. The impact of alertness on the neural networks governing visuospatial attention is, however, poorly understood. By using a transcranial magnetic stimulation twin-coil approach, the present study aimed at investigating the effects of an alertness manipulation on the excitability of the left and the right posterior parietal cortices (PPCs), crucial nodes of the visuospatial attentional network. Participants' visuospatial attentional deployment was assessed with a free visual exploration task and concurrent eye tracking. Their alertness level was manipulated through the time of the day, that is, by testing chronotypically defined evening types both during their circadian on- and off-peak times. The results revealed an increased excitability of the left compared with the right PPC during low alertness. On the horizontal dimension, these results were accompanied by a significant rightward shift in the center and a bilateral narrowing in the periphery of the visual exploration field, as well as a central upward shift on the vertical dimension. The findings show that the manipulation of non-spatial attentional aspects (i.e., alertness) can affect visuospatial attentional deployment and modulate the excitability of areas subtending spatial attentional control. |
Adam Palanica; Roxane J. Itier Asymmetry in gaze direction discrimination between the upper and lower visual fields Journal Article In: Perception, vol. 46, no. 8, pp. 941–955, 2017. @article{Palanica2017, Previous research has shown that gaze direction can only be accurately discriminated within parafoveal limits (?5? eccentricity) along the horizontal visual field. Beyond this eccentricity, head orientation seems to influence gaze discrimination more than iris cues. The present study examined gaze discrimination performance in the upper visual field (UVF) and lower visual field (LVF), and whether head orientation affects gaze judgments beyond parafoveal vision. Direct and averted gaze faces, in frontal and deviated head orientations, were presented for 150 ms along the vertical meridian while participants maintained central fixation during gaze discrimination judgments. Gaze discrimination was above chance level at all but one eccentricity for the two gaze-head congruent conditions. In contrast, for the incongruent conditions, gaze was discriminated above chance only from –1.5? to þ3?, with an asymmetry between the UVF and LVF. Beyond foveal vision, response rates were biased toward head orientation rather than iris eccentricity, occurring in the LVF for both head orientations, and in the UVF for frontal head views. These findings suggest that covert processing of gaze direction involves the integration of eyes and head cues, with congruency of these two social cues driving response differences between the LVF and the UVF. |
Dimitrios J. Palidis; Pearson A. Wyder-Hodge; Jolande Fooken; Miriam Spering Distinct eye movement patterns enhance dynamic visual acuity Journal Article In: PLoS ONE, vol. 12, no. 2, pp. e0172061, 2017. @article{Palidis2017, Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics—eye latency, acceleration, velocity gain, position error—and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns—minimizing eye position error, tracking smoothly, and inhibiting reverse saccades—were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA. |
Hayley Crawford; Joanna Moss; Chris Oliver; Deborah M. Riby Differential effects of anxiety and autism on social scene scanning in males with fragile X syndrome Journal Article In: Journal of Neurodevelopmental Disorders, vol. 9, pp. 1–10, 2017. @article{Crawford2017a, BACKGROUND: Existing literature draws links between social attention and socio-behavioural profiles in neurodevelopmental disorders. Fragile X syndrome (FXS) is associated with a known socio-behavioural phenotype of social anxiety and social communication difficulties alongside high social motivation. However, studies investigating social attention in males with FXS are scarce. Using eye tracking, this study investigates social attention and its relationship with both anxiety and autism symptomatology in males with FXS. METHODS: We compared dwell times to the background, body, and face regions of naturalistic social scenes in 11 males with FXS (M age = 26.29) and 11 typically developing (TD) children who were matched on gender and receptive language ability (M age = 6.28). Using informant-report measures, we then investigated the relationships between social scene scanning and anxiety, and social scene scanning and social communicative impairments. RESULTS: Males with FXS did not differ to TD children on overall dwell time to the background, body, or face regions of the naturalistic social scenes. Whilst males with FXS displayed developmentally 'typical' social attention, increased looking at faces was associated with both heightened anxiety and fewer social communication impairments in this group. CONCLUSIONS: These results offer novel insights into the mechanisms associated with social attention in FXS and provide evidence to suggest that anxiety and autism symptomatology, which are both heightened in FXS, have differential effects on social attention |
Trevor J. Crawford; Eleanor S. Smith; Donna M. Berry Eye gaze and aging: Selective and combined effects of working memory and inhibitory control Journal Article In: Frontiers in Human Neuroscience, vol. 11, pp. 563, 2017. @article{Crawford2017, Eye-tracking is increasingly studied as a cognitive and biological marker for the early signs of neuropsychological and psychiatric disorders. However, in order to make further progress, a more comprehensive understanding of the age-related effects on eye- tracking is essential. The antisaccade task requires participants to make saccadic eye movements away from a prepotent stimulus. Speculation on the cause of the observed age-related differences in the antisaccade task largely centers around two sources of cognitive dysfunction: inhibitory control (IC) and working memory (WM). The IC account views cognitive slowing and task errors as a direct result of the decline of inhibitory cognitive mechanisms. An alternative theory considers that a deterioration of WM is the cause of these age-related effects on behavior. The current study assessed IC and WM processes underpinning saccadic eye movements in young and older participants. This was achieved with three experimental conditions that systematically varied the extent to which WM and IC were taxed in the antisaccade task: a memory-guided task was used to explore the effect of increasing the WM load; a Go/No-Go task was used to explore the effect of increasing the inhibitory load; a ‘standard' antisaccade task retained the standard WM and inhibitory loads. Saccadic eye movements were also examined in a control condition: the standard prosaccade task where the load of WM and IC were minimal or absent. Saccade latencies, error rates and the spatial accuracy of saccades of older participants were compared to the same measures in healthy young controls across the conditions. The results revealed that aging is associated with changes in both IC and WM. Increasing the inhibitory load was associated with increased reaction times in the older group, while the increased WM load and the inhibitory load contributed to an increase in the antisaccade errors. These results reveal that aging is associated with changes in both IC and WM. |
Kate Crookes; Gillian Rhodes Poor recognition of other-race faces cannot always be explained by a lack of effort Journal Article In: Visual Cognition, vol. 25, no. 4-6, pp. 430–441, 2017. @article{Crookes2017, People are generally better at recognizing own-race than other-race faces. This "other-race effect" is very well established although the underlying causes are much debated. Social-cognitive accounts argue that the other-race effect stems from a lack of motivation to individuate other-race faces, whereas perceptual expertise accounts argue that it reflects the tuning of face-processing mechanisms by experience to own-race faces. We investigated the effort people apply to recognize own-race and other-race faces. Caucasian participants completed the Australian and Chinese Cambridge Face Memory Tasks, once with the standard timing and once with self-paced study phases. If people are less motivated to recognize other-race faces they should apply less effort, that is, when given control over viewing times they should spend less time studying other-race than own-race faces. Contrary to social-cognitive accounts, there was no evidence of reduced effort for other-race faces. Participants did not spend less time studying other-race than own-race faces in the self-paced condition. Moreover, participants reported applying significantly more effort to telling apart other-race than own-race faces. These results are not consistent with reduced motivation to individuate other-race faces. Thus, they appear more consistent with perceptual expertise rather than social-cognitive accounts of the other-race effect.Copyright ©2017 Informa UK Limited, trading as Taylor & Francis Group. |
Joke Daems; Sonia Vandepitte; Robert J. Hartsuiker; Lieve Macken Translation methods and experience: A comparative analysis of human translation and post-editing with students and professional translators Journal Article In: Meta, vol. 62, no. 2, pp. 245–270, 2017. @article{Daems2017, While the benefits of using post-editing for technical texts have been more or less acknowledged, it remains unclear whether post-editing is a viable alternative to human translation for more general text types. In addition, we need a better understanding of both translation methods and how they are performed by students as well as professionals, so that pitfalls can be determined and translator training can be adapted accordingly. In this article, we aim to get a better understanding of the differences between human translation and post-editing for newspaper articles. Processes are registered by means of eye tracking and keystroke logging, which allows us to study translation speed, cognitive load, and the use of external resources. We also look at the final quality of the product as well as translators' attitude towards both methods of translation. Studying these different aspects shows that both methods and groups are more similar than anticipated. |
Olga Dal Monte; Matthew Piva; Kevin M. Anderson; Marios Tringides; Avram J. Holmes; Steve W. C. Chang Oxytocin under opioid antagonism leads to supralinear enhancement of social attention Journal Article In: Proceedings of the National Academy of Sciences, vol. 114, no. 20, pp. 5247–5252, 2017. @article{DalMonte2017, To provide new preclinical evidence toward improving the efficacy of oxytocin (OT) in treating social dysfunction, we tested the benefit of administering OT under simultaneously induced opioid antagonism during dyadic gaze interactions in monkeys. OT coadministered with a μ-opioid receptor antagonist, naloxone, invoked a supralinear enhancement of prolonged and selective social attention, producing a stronger effect than the summed effects of each administered separately. These effects were consistently observed when averaging over entire sessions, as well as specifically following events of particular social importance, including mutual eye contact and mutual reward receipt. Furthermore, attention to various facial regions was differentially modulated depending on social context. Using the Allen Institute's transcriptional atlas, we further established the colocalization of μ-opioid and κ-opioid receptor genes and OT genes at the OT-releasing sites in the human brain. These data across monkeys and humans support a regulatory relationship between the OT and opioid systems and suggest that administering OT under opioid antagonism may boost the therapeutic efficacy of OT for enhancing social cognition. |
Mario Dalmaso; Luigi Castelli; Giovanni Galfano Attention holding elicited by direct-gaze faces is reflected in saccadic peak velocity Journal Article In: Experimental Brain Research, vol. 235, no. 11, pp. 3319–3332, 2017. @article{Dalmaso2017, Manual response times to peripherally presented targets have been reported to be greater in the presence of task-irrelevant pictorial faces at fxation which establish an eye contact with the observer. This efect is interpreted as evidence that direct-gaze faces hold attention. In three experiments, we investigated whether this attention-holding efect is also refected in saccadic response times. Participants were asked to make a saccade towards a symbolic target that could appear rightwards or leftwards, in the presence of a task-irrelevant centrally placed face with either direct gaze or closed eyes. Unexpectedly, saccadic response times did not show any consistent response pattern as a function of whether the faces were presented with direct gaze vs. closed eyes. Interestingly, saccadic peak velocities were found to be lower in the presence of faces with direct gaze rather than closed eyes (Experiment 1). This efect emerged even in the presence of non-human primate faces (Experiment 2), and no diferences between direct gaze and closed eyes emerged when the faces were presented inverted rather than upright (Experiment 3). Overall, these findings suggest that eye contact can have an impact on the saccadic generation system. |
Mario Dalmaso; Luigi Castelli; Pietro Scatturin; Giovanni Galfano Trajectories of social vision: Eye contact increases saccadic curvature Journal Article In: Visual Cognition, vol. 25, no. 1-3, pp. 358–365, 2017. @article{Dalmaso2017b, Saccades are known to deviate away from distractors, and the amplitude of this deviation seems to reflect the salience of these stimuli, as in the case of human faces. Here, we investigated whether eye contact can modulate attention allocation by examining saccadic curvature when faces with closed vs. open eyes act as distractors. In two experiments, participants were asked to perform a vertical saccade towards a symbolic target. At the same time, task-irrelevant faces with open or closed eyes (Experiments 1 and 2) and scrambled faces (Experiment 2) could appear leftwards or rightwards with respect to the ideal trajectory towards the target. Overall, a greater saccadic curvature was observed in response to faces with open eyes, as compared to the other two conditions. These results confirm that eye contact plays an important role in shaping attentional mechanisms and provide further evidence concerning the link between social vision and eye movements. |
Mario Dalmaso; Luigi Castelli; Pietro Scatturin; Giovanni Galfano Working memory load modulates microsaccadic rate Journal Article In: Journal of Vision, vol. 17, no. 3, pp. 1–12, 2017. @article{Dalmaso2017a, Microsaccades are tiny eye movements that individuals perform unconsciously during fixation. Despite that the nature and the functions of microsaccades are still lively debated, recent evidence has shown an association between these micro eye movements and higher order cognitive processes. Here, in two experiments, we specifically focused on working memory and addressed whether differential memory load could be reflected in a modulation of microsaccade dynamics. In Experiment 1, participants memorized a numerical sequence composed of either two (low-load condition) or five digits (high- load condition), appearing at fixation. The results showed a reduction in the microsaccadic rate in the high- load compared to the low-load condition. In Experiment 2, five red or green digits were always presented at fixation. Participants either memorized the color (low- load condition) or the five digits (high-load condition). Hence, visual stimuli were exactly the same in both conditions. Consistent with Experiment 1, microsaccadic rate was lower in the high-load than in the low-load condition. Overall, these findings reveal that an engagement of working memory can have an impact on microsaccadic rate, consistent with the view that microsaccade generation is pervious to top-down processes. |
Atser Damsma; Hedderik Rijn Pupillary response indexes the metrical hierarchy of unattended rhythmic violations Journal Article In: Brain and Cognition, vol. 111, pp. 95–103, 2017. @article{Damsma2017, The perception of music is a complex interaction between what we hear and our interpretation. This is reflected in beat perception, in which a listener infers a regular pulse from a musical rhythm. Although beat perception is a fundamental human ability, it is still unknown whether attention to the music is necessary to establish the perception of stronger and weaker beats, or meter. In addition, to what extent beat perception is dependent on musical expertise is still a matter of debate. Here, we address these questions by measuring the pupillary response to omissions at different metrical positions in drum rhythms, while participants attended to another task. We found that the omission of the salient first beat elicited a larger pupil dilation than the omission of the less-salient second beat. This result shows that participants not only detected the beat without explicit attention to the music, but also perceived a metrical hierarchy of stronger and weaker beats. This suggests that hierarchical beat perception is an automatic process that requires no or minimal attentional resources. In addition, we found no evidence for the hypothesis that hierarchical beat perception is affected by musical expertise, suggesting that elementary beat perception might be independent from musical expertise. Finally, our results show that pupil dilation reflects surprise without explicit attention, demonstrating that the pupil is an accessible index to signatures of unattentive processing. |
Christopher L. Dancy; Frank E. Ritter IGT-Open: An open-source, computerized version of the Iowa Gambling Task Journal Article In: Behavior Research Methods, vol. 49, no. 3, pp. 972–978, 2017. @article{Dancy2017, The Iowa Gambling Task (IGT) is commonly used to understand the processes involved in decision-making. Though the task was originally run without a computer, using a computerized version of the task has become typical. These computerized versions of the IGT are useful, because they can make the task more standardized across studies and allow for the task to be used in environments where a physical version of the task may be difficult or impossible to use (e.g., while collecting brain imaging data). Though these computerized versions of the IGT have been useful for experimentation, having multiple software implementations of the task could present reliability issues. We present an open-source software version of the Iowa Gambling Task (called IGT-Open) that allows for millisecond visual presentation accuracy and is freely available to be used and modified. This software has been used to collect data from human subjects and also has been used to run model-based simulations with computational process models developed to run in the ACT-R architecture. |
Gina M. D'Andrea-Penna; Sebastian M. Frank; Todd F. Heatherton; Peter U. Tse Distracting tracking: Interactions between negative emotion and attentional load in multiple-object tracking Journal Article In: Emotion, vol. 17, no. 6, pp. 900–904, 2017. @article{DAndreaPenna2017, Stimuli that attract exogenous attention have been shown to interfere with behavioral performance on various tasks. In the present study, participants performed multiple-object tracking (MOT) in conditions where either neutral or negatively valenced images were flashed at fixation. Results reveal a significant impairment of tracking accuracy in the emotional MOT conditions compared to the neutral conditions specifically at the highest level of task difficulty. These findings suggest that emotional distraction is most detrimental when maximal endogenous attentional engagement is required. This interaction between emotional distraction and attentional load is inconsistent with existing models of emotional distraction. |
Yarden Dankner; Lilach Shalev; Marisa Carrasco; Shlomit Yuval-Greenberg Prestimulus inhibition of saccades in adults with and without attention-deficit/hyperactivity disorder as an index of temporal expectations Journal Article In: Psychological Science, vol. 28, no. 7, pp. 835–850, 2017. @article{Dankner2017, Reports an error in "Prestimulus inhibition of saccades in adults with and without attention-deficit/hyperactivity disorder as an index of temporal expectations" by Yarden Dankner, Lilach Shalev, Marisa Carrasco and Shlomit Yuval-Greenberg ( Psychological Science, 2017[Jul], Vol 28[7], 835-850). In the original article, there were some errors in Figures 4, 7, and 9. The corrected Figures 4, 7, and 9 are present in the erratum. (The following abstract of the original article appeared in record 2017-30892-001). Knowing when to expect important events to occur is critical for preparing context-appropriate behavior. However, anticipation is inherently complicated to assess because conventional measurements of behavior, such as accuracy and reaction time, are available only after the predicted event has occurred. Anticipatory processes, which occur prior to target onset, are typically measured only retrospectively by these methods. In this study, we utilized a novel approach for assessing temporal expectations through the dynamics of prestimulus saccades. Results showed that saccades of neurotypical participants were inhibited prior to the onset of stimuli that appeared at predictable compared with less predictable times. No such inhibition was found in most participants with attention-deficit/hyperactivity disorder (ADHD), and particularly not in those who experienced difficulties in sustaining attention over time. These findings suggest that individuals with ADHD, especially those with sustained-attention deficits, have diminished ability to benefit from temporal predictability, and this could account for some of their context-inappropriate behaviors. |
Joshua Davis; Elinor McKone; Marc Zirnsak; Tirin Moore; Richard O'Kearney; Deborah Apthorp; Romina Palermo Social and attention-to-detail subclusters of autistic traits differentially predict looking at eyes and face identity recognition ability Journal Article In: British Journal of Psychology, vol. 108, no. 1, pp. 191–219, 2017. @article{Davis2017, This study distinguished between different subclusters of autistic traits in the general population and examined the relationships between these subclusters, looking at the eyes of faces, and the ability to recognize facial identity. Using the Autism Spectrum Quotient (AQ) measure in a university-recruited sample, we separate the social aspects of autistic traits (i.e., those related to communication and social interaction; AQ-Social) from the non-social aspects, particularly attention-to-detail (AQ-Attention). We provide the first evidence that these social and non-social aspects are associated differentially with looking at eyes: While AQ-Social showed the commonly assumed tendency towards reduced looking at eyes, AQ-Attention was associated with increased looking at eyes. We also report that higher attention-to-detail (AQ-Attention) was then indirectly related to improved face recognition, mediated by increased number of fixations to the eyes during face learning. Higher levels of socially relevant autistic traits (AQ-Social) trended in the opposite direction towards being related to poorer face recognition (significantly so in females on the Cambridge Face Memory Test). There was no evidence of any mediated relationship between AQ-Social and face recognition via reduced looking at the eyes. These different effects of AQ-Attention and AQ-Social suggest face-processing studies in Autism Spectrum Disorder might similarly benefit from considering symptom subclusters. Additionally, concerning mechanisms of face recognition, our results support the view that more looking at eyes predicts better face memory. |
Anouk J. Brouwer; Tayler Jarvis; Jason P. Gallivan; J. Randall Flanagan Parallel specification of visuomotor feedback gains during bimanual reaching to independent goals Journal Article In: eNeuro, vol. 4, no. 2, pp. 1–12, 2017. @article{Brouwer2017, During goal-directed reaching, rapid visuomotor feedback processes enable the human motor system to quickly correct for errors in the trajectory of the hand that arise from motor noise and, in some cases, external perturbations. To date, these visuomotor responses, the gain of which is sensitive to features of the task and environment, have primarily been examined in the context of unimanual reaching movements toward a single target. However, many natural tasks involve moving both hands together, often to separate targets, such that errors can occur in parallel and at different spatial locations. Here, we examined the resource capacity of automatic visuomotor corrective mechanisms by comparing feedback gains during bimanual reaches, toward two targets, to feedback gains during unimanual reaches toward single targets. To investigate the sensitivity of the feedback gains and their relation to visual-spatial processing, we manipulated the widths of the targets and participants' gaze location. We found that the gain of corrective responses to cursor displacements, while strongly modulated by target width and gaze position, were only slightly reduced during bimanual control. Our results show that automatic visuomotor corrective mechanisms can efficiently operate in parallel across multiple spatial locations. |
Jan Willem Gee; Olympia Colizoli; Niels A. Kloosterman; Tomas Knapen; Sander Nieuwenhuis; Tobias H. Donner Dynamic modulation of decision biases by brainstem arousal systems Journal Article In: eLife, vol. 6, pp. 1–36, 2017. @article{Gee2017, Decision-makers often arrive at different choices when faced with repeated presentations of the same evidence. Variability of behavior is commonly attributed to noise in the brain's decision-making machinery. We hypothesized that phasic responses of brainstem arousal systems are a significant source of this variability. We tracked pupil responses (a proxy of phasic arousal) during sensory-motor decisions in humans, across different sensory modalities and task protocols. Large pupil responses generally predicted a reduction in decision bias. Using fMRI, we showed that the pupil-linked bias reduction was (i) accompanied by a modulation of choice-encoding pattern signals in parietal and prefrontal cortex and (ii) predicted by phasic, pupil-linked responses of a number of neuromodulatory brainstem centers involved in the control of cortical arousal state, including the noradrenergic locus coeruleus. We conclude that phasic arousal suppresses decision bias on a trial-by-trial basis, thus accounting for a significant component of the variability of choice behavior. |
Floor Groot; Falk Huettig; Christian N. L. Olivers Language-induced visual and semantic biases in visual search are subject to task requirements Journal Article In: Visual Cognition, vol. 25, no. 1-3, pp. 225–240, 2017. @article{Groot2017, Visual attention is biased by both visual and semantic representations activated by words. We investigated to what extent language-induced visual and semantic biases are subject to task demands. Participants memorized a spoken word for a verbal recognition task, and performed a visual search task during the retention period. Crucially, while the word had to be remembered in all conditions, it was either relevant for the search (as it also indicated the target) or irrelevant (as it only served the memory test afterwards). On critical trials, displays contained objects that were visually or semantically related to the memorized word. When the word was relevant for the search, eye movement biases towards visually related objects arose earlier and more strongly than biases towards semantically related objects. When the word was irrelevant there was still evidence for visual and semantic biases, but these biases were substantially weaker and similar in strength and temporal dynamics without a visual advantage. We conclude that language-induced attentional biases are subject to task requirements. |
Isabelle Boutet; Chantal L. Lemieux; Marc André Goulet; Charles A. Collin Faces elicit different scanning patterns depending on task demands Journal Article In: Attention, Perception, and Psychophysics, vol. 79, no. 4, pp. 1050–1063, 2017. @article{Boutet2017, Eye movements were recorded while participants discriminated upright and inverted faces that differed with respect to either configural or featural information. Two hypotheses were examined: (1) whether featural and configural information processing elicit different scanning patterns; (2) whether fixations on a specific region of the face dominate scanning patterns. Results from two experiments were compared to examine whether participants' prior knowledge of the kind of information that would be relevant for the task (i.e., configural vs featural) influences eye movements. In Experiment 1, featural and configural discrimination trials were presented in random order such that participants were unaware of the information that would be relevant on any given trial. In Experiment 2, featural and configural discrimination trials were blocked and participants were informed of the nature of the discriminations. The results of both experiments suggest that faces elicit different scanning patterns depending on task demands. When participants were unaware of the nature of the information relevant for the task at hand, face processing was dominated by attention to the eyes. When participants were aware that relational information was relevant, scanning was dominated by fixations to the center of the face. We conclude that faces elicit scanning strategies that are driven by task demands. |
Vanessa K. Bowden; Rebekah E. Smith; Shayne Loft Eye movements provide insights into the conscious use of context in prospective memory Journal Article In: Consciousness and Cognition, vol. 52, pp. 68–74, 2017. @article{Bowden2017, Prior research examining the impact of context on prospective memory (PM) has produced mixed results. Our study aimed to determine whether providing progressive context information could increase PM accuracy and reduce costs to ongoing tasks. Seventy-two participants made ongoing true/false judgements for simple sentences while maintaining a PM intention to respond differently to four memorised words. The context condition were informed of the trial numbers where PM targets could appear, and eye-tracking recorded trial number fixation frequency. The context condition showed reduced costs during irrelevant contexts, increased costs during relevant contexts, and had better PM accuracy compared to a standard condition that was not provided with context. The context condition also made an increasing number of trial number fixations leading up to relevant contexts, indicating the conscious use of context. Furthermore, this trial number checking was beneficial to PM, with participants who checked more frequently having better PM accuracy. |
Rodrigo M. Braga; Randy L. Buckner Parallel interdigitated distributed networks within the individual estimated by intrinsic functional connectivity Journal Article In: Neuron, vol. 95, no. 2, pp. 457–471.e5, 2017. @article{Braga2017, Certain organizational features of brain networks present in the individual are lost when central tendencies are examined in the group. Here we investigated the detailed network organization of four individuals each scanned 24 times using MRI. We discovered that the distributed network known as the default network is comprised of two separate networks possessing adjacent regions in eight or more cortical zones. A distinction between the networks is that one is coupled to the hippocampal formation while the other is not. Further exploration revealed that these two networks were juxtaposed with additional networks that themselves fractionate group-defined networks. The collective networks display a repeating spatial progression in multiple cortical zones, suggesting that they are embedded within a broad macroscale gradient. Regions contributing to the newly defined networks are spatially variable across individuals and adjacent to distinct networks, raising issues for network estimation in group-averaged data and applied endeavors, including targeted neuromodulation. Braga and Buckner examine the detailed organization of brain networks within individual people. They discovered that multiple closely juxtaposed cortical regions form parallel distributed networks. Separate large-scale networks may emerge from a common organizing principle. |
Frank Bremmer; Jan Churan; Markus Lappe Heading representations in primates are compressed by saccades Journal Article In: Nature Communications, vol. 8, pp. 920, 2017. @article{Bremmer2017, Perceptual illusions help to understand how sensory signals are decoded in the brain. Here we report that the opposite approach is also applicable, i.e., results from decoding neural activity from monkey extrastriate visual cortex correctly predict a hitherto unknown per- ceptual illusion in humans. We record neural activity from monkey medial superior temporal (MST) and ventral intraparietal (VIP) area during presentation of self-motion stimuli and concurrent reflexive eye movements. A heading-decoder performs veridically during slow eye movements. During fast eye movements (saccades), however, the decoder erroneously reports compression of heading toward straight ahead. Functional equivalents of macaque areas MST and VIP have been identified in humans, implying a perceptual correlate (illusion) of this perisaccadic decoding error. Indeed, a behavioral experiment in humans shows that perceived heading is perisaccadically compressed toward the direction of gaze. Response properties of primate areas MST and VIP are consistent with being the substrate of the newly described visual illusion. |
Donna J. Bridge; Neal J. Cohen; Joel L. Voss Distinct hippocampal versus frontoparietal network contributions to retrieval and memory-guided exploration Journal Article In: Journal of Cognitive Neuroscience, vol. 29, no. 8, pp. 1324–1338, 2017. @article{Bridge2017, Memory can profoundly influence new learning, presumably because memory optimizes exploration of to-be-learned material. Although hippocampus and frontoparietal networks have been implicated in memory-guided exploration, their specific and interactive roles have not been identified. We examined eye movements during fMRI scanning to identify neural correlates of the influences of memory retrieval on exploration and learning. After retrieval of one object in a multiobject array, viewing was strategically directed away from the retrieved object toward nonretrieved objects, such that exploration was directed toward to-be-learned content. Retrieved objects later served as optimal reminder cues, indicating that exploration caused memory to become structured around the retrieved content. Hippocampal activity was associated with memory retrieval, whereas frontoparietal activity varied with strategic viewing patterns deployed after retrieval, thus providing spatiotemporal dissociation of memory retrieval from memory-guided learning strategies. Time-lagged fMRI connectivity analyses indicated that hippocampal activity predicted frontoparietal activity to a greater extent for a condition in which retrieval guided exploration occurred than for a passive control condition in which exploration was not influenced by retrieval. This demonstrates network-level interaction effects specific to influences of memory on strategic exploration. These findings show how memory guides behavior during learning and demonstrate distinct yet interactive hippocampal-frontoparietal roles in implementing strategic exploration behaviors that determine the fate of evolving memory representations. |
Andreas Brocher; Tim Graf Decision-related factors in pupil old/new effects: Attention, response execution, and false memory Journal Article In: Neuropsychologia, vol. 102, pp. 124–134, 2017. @article{Brocher2017, In this study, we investigate the effects of decision-related factors on recognition memory in pupil old/new paradigms. In Experiment 1, we used an old/new paradigm with words and pseudowords and participants made lexical decisions during recognition rather than old/new decisions. Importantly, participants were instructed to focus on the nonword-likeness of presented items, not their word-likeness. We obtained no old/new effects. In Experiment 2, participants discriminated old from new words and old from new pseudowords during recognition, and they did so as quickly as possible. We found old/new effects for both words and pseudowords. In Experiment 3, we used materials and an old/new design known to elicit a large number of incorrect responses. For false alarms (“old” response for new word), we found larger pupils than for correctly classified new items, starting at the point at which response execution was allowed (2750 ms post stimulus onset). In contrast, pupil size for misses (“new” response for old word) was statistically indistinguishable from pupil size in correct rejections. Taken together, our data suggest that pupil old/new effects result more from the intentional use of memory than from its automatic use. |
Antonios I. Christou; Yvonne Wallis; Hayley Bair; Maurice Zeegers; Joseph P. McCleery Serotonin 5-HTTLPR genotype modulates reactive visual scanning of social and non-social affective stimuli in young children Journal Article In: Frontiers in Behavioral Neuroscience, vol. 11, pp. 118, 2017. @article{Christou2017, Previous studies have documented the 5-HTTLPR polymorphisms as genetic variants that are involved in serotonin availability and also associated with emotion regulation and facial emotion processing. In particular, neuroimaging and behavioral studies of healthy populations have produced evidence to suggest that carriers of the Short allele exhibit heightened neurophysiological and behavioral reactivity when processing aversive stimuli, particularly in brain regions involved in fear. However, an additional distinction has emerged in the field, which highlights particular types of fearful information, i.e., aversive information which involves a social component versus non-social aversive stimuli. Although processing of each of these stimulus types (social and non-social) is believed to involve a subcortical neural system which includes the amygdala, evidence also suggests that the amygdala itself may be particularly responsive to socially significant environmental information, potentially due to the critical relevance of social information for humans. Examining individual differences in neurotransmitter systems which operate within this subcortical network, and in particular the serotonin system, may be critically informative for furthering our understanding of the neurobiological mechanisms underlying responses to emotional and affective stimuli. In the present study we examine visual scanning patterns in response to both aversive and positive images of a social or non-social nature in relation to 5-HTTLPR genotypes, in 49 children aged 4-7 years. Results indicate that children with at least one Short 5-HTTLPR allele spent less time fixating the threat-related non-social stimuli, compared with participants with two copies of the Long allele. Interestingly, a separate set of analyses suggests that carriers of two copies of the short 5-HTTLPR allele also spent less time fixating both the negative and positive non-social stimuli. Together, these findings support the hypothesis that genetically mediated differences in serotonin availability mediate behavioral responses to different types of emotional stimuli in young children. |
Tim Chuk; Antoni B. Chan; Janet H. Hsiao In: Vision Research, vol. 141, pp. 204–216, 2017. @article{Chuk2017a, The hidden Markov model (HMM)-based approach for eye movement analysis is able to reflect individual differences in both spatial and temporal aspects of eye movements. Here we used this approach to understand the relationship between eye movements during face learning and recognition, and its association with recognition performance. We discovered holistic (i.e., mainly looking at the face center) and analytic (i.e., specifically looking at the two eyes in addition to the face center) patterns during both learning and recognition. Although for both learning and recognition, participants who adopted analytic patterns had better recognition performance than those with holistic patterns, a significant positive correlation between the likelihood of participants' patterns being classified as analytic and their recognition performance was only observed during recognition. Significantly more participants adopted holistic patterns during learning than recognition. Interestingly, about 40% of the participants used different patterns between learning and recognition, and among them 90% switched their patterns from holistic at learning to analytic at recognition. In contrast to the scan path theory, which posits that eye movements during learning have to be recapitulated during recognition for the recognition to be successful, participants who used the same or different patterns during learning and recognition did not differ in recognition performance. The similarity between their learning and recognition eye movement patterns also did not correlate with their recognition performance. These findings suggested that perceptuomotor memory elicited by eye movement patterns during learning does not play an important role in recognition. In contrast, the retrieval of diagnostic information for recognition, such as the eyes for face recognition, is a better predictor for recognition performance. |
Tim Chuk; Kate Crookes; William G. Hayward; Antoni B. Chan; Janet H. Hsiao Hidden Markov model analysis reveals the advantage of analytic eye movement patterns in face recognition across cultures Journal Article In: Cognition, vol. 169, pp. 102–117, 2017. @article{Chuk2017, It remains controversial whether culture modulates eye movement behavior in face recognition. Inconsistent results have been reported regarding whether cultural differences in eye movement patterns exist, whether these differences affect recognition performance, and whether participants use similar eye movement patterns when viewing faces from different ethnicities. These inconsistencies may be due to substantial individual differences in eye movement patterns within a cultural group. Here we addressed this issue by conducting individual-level eye movement data analysis using hidden Markov models (HMMs). Each individual's eye movements were modeled with an HMM. We clustered the individual HMMs according to their similarities and discovered three common patterns in both Asian and Caucasian participants: holistic (looking mostly at the face center), left-eye-biased analytic (looking mostly at the two individual eyes in addition to the face center with a slight bias to the left eye), and right-eye-based analytic (looking mostly at the right eye in addition to the face center). The frequency of participants adopting the three patterns did not differ significantly between Asians and Caucasians, suggesting little modulation from culture. Significantly more participants (75%) showed similar eye movement patterns when viewing own- and other-race faces than different patterns. Most importantly, participants with left-eye-biased analytic patterns performed significantly better than those using either holistic or right-eye-biased analytic patterns. These results suggest that active retrieval of facial feature information through an analytic eye movement pattern may be optimal for face recognition regardless of culture. |
Helen E. Clark; John A. Perrone; Robert B. Isler; Samuel G. Charlton Fixating on the size-speed illusion of approaching railway trains: What we can learn from our eye movements Journal Article In: Accident Analysis and Prevention, vol. 99, pp. 110–113, 2017. @article{Clark2017, Railway level crossing collisions have recently been linked to a size-speed illusion where larger objects such as trains appear to move slower than smaller objects such as cars. An explanation for this illusion has centred on observer eye movements – particularly in relation to the larger, longer train. A previous study (Clark et al., 2016) found participants tend to make initial fixations to locations around the visual centroid of a moving vehicle; however individual eye movement patterns tended to be either fixation-saccade-fixation type, or smooth pursuit. It is therefore unknown as to which type of eye movement contributes to the size-speed illusion. This study isolated fixation eye movements by requiring participants to view computer animated sequences in a laboratory setting, where a static fixation square was placed in the foreground at one of two locations on a train (front and centroid). Results showed that even with the square placed around the front location of a vehicle, participants still underestimated the speed of the train relative to the car and underestimation was greater when the square was placed around the visual centroid of the train. Our results verify that manipulation of eye movement behaviour can be effective in reducing the magnitude of the size-speed illusion and propose that interventions based on this manipulation should be designed and tested for effectiveness. |
Ivar Adrianus H. Clemens; Luc P. J. Selen; Antonella Pomante; Paul R. MacNeilage; W. Pieter Medendorp Eye movements in darkness modulate self-motion perception Journal Article In: eNeuro, vol. 4, no. 1, pp. 1–12, 2017. @article{Clemens2017, During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first (n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment (n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation. |
Daniel R. Coates; Johan Wagemans; Bilge Sayim Diagnosing the periphery: Using the Rey-Osterrieth Complex Figure drawing test to characterize peripheral visual function Journal Article In: i-Perception, vol. 8, no. 3, pp. 1–20, 2017. @article{Coates2017, Peripheral vision is strongly limited by crowding, the deleterious influence of neighboring stimuli on target perception. Many quantitative aspects of this phenomenon have been characterized, but the specific nature of the perceptual degradation remains elusive. We utilized a drawing technique to probe the phenomenology of peripheral vision, using the Rey–Osterrieth Complex Figure, a standard neuropsychological clinical instrument. The figure was presented at 12° or 6° in the right visual field, with eye tracking to ensure that the figure was only presented when observers maintained stable fixation. Participants were asked to draw the figure with free viewing, capturing its peripheral appearance. A foveal condition was used to measure copying performance in direct view. To assess the drawings, two raters used standard scoring systems that evaluated feature positions, spatial distortions, and omission errors. Feature scores tended to decrease with increasing eccentricity, both within and between conditions... |
Andrew L. Cohen; Namyi Kang; Tanya L. Leise Multi-attribute, multi-alternative models of choice: Choice, reaction time, and process tracing Journal Article In: Cognitive Psychology, vol. 98, pp. 45–72, 2017. @article{Cohen2017, The first aim of this research is to compare computational models of multi-alternative, multi-attribute choice when attribute values are explicit. The choice predictions of utility (standard random utility & weighted valuation), heuristic (elimination-by-aspects, lexicographic, & maximum attribute value), and dynamic (multi-alternative decision field theory, MDFT, & a version of the multi-attribute linear ballistic accumulator, MLBA) models are contrasted on both preferential and risky choice data. Using both maximum likelihood and cross-validation fit measures on choice data, the utility and dynamic models are preferred over the heuristic models for risky choice, with a slight overall advantage for the MLBA for preferential choice. The response time predictions of these models (except the MDFT) are then tested. Although the MLBA accurately predicts response time distributions, it only weakly accounts for stimulus-level differences. The other models completely fail to account for stimulus-level differences. Process tracing measures, i.e., eye and mouse tracking, were also collected. None of the qualitative predictions of the models are completely supported by that data. These results suggest that the models may not appropriately represent the interaction of attention and preference formation. To overcome this potential shortcoming, the second aim of this research is to test preference-formation assumptions, independently of attention, by developing the models of attentional sampling (MAS) model family which incorporates the empirical gaze patterns into a sequential sampling framework. An MAS variant that includes attribute values, but only updates the currently viewed alternative and does not contrast values across alternatives, performs well in both experiments. Overall, the results support the dynamic models, but point to the need to incorporate a framework that more accurately reflects the relationship between attention and the preference-formation process. |
Merryn D. Constable; Stefanie I. Becker Right away: A late, right-lateralized category effect complements an early, left-lateralized category effect in visual search Journal Article In: Psychonomic Bulletin & Review, vol. 24, no. 5, pp. 1611–1619, 2017. @article{Constable2017, According to the Sapir–Whorf hypothesis, learned semantic categories can influence early perceptual processes. A central finding in support of this view is the lateralized category effect—namely, the finding that categorically different colors (e.g., blue and green hues) can be discriminated faster than colors within the same color category (e.g., differ- ent hues of green), especially when they are presented in the right visual field. Because the right visual field projects to the left hemisphere, this finding has been popularly couched in terms of the left-lateralization of language. However, other studies have reported bilateral category effects, which has led some researchers to question the linguistic origins of the effect. Here we examined the time course of lateralized and bilateral category effects in the classical visual search paradigm by means of eyetracking and RT distribution analyses. Our results show a bilateral category effect in the manual responses, which is combined ofan early, left-lateralized category effect and a later, right-lateralized category effect. The newly discovered late, right-lateralized category effect occurred only when observers had difficulty locating the target, indicating a specialization ofthe right hemisphere to find categorically different targets after an initial error. The finding that early and late stages of visual search show different lateralized category effects can explain a wide range ofpreviously discrepant findings. |
Tim H. W. Cornelissen; Melissa L. -H. Võ Stuck on semantics: Processing of irrelevant object-scene inconsistencies modulates ongoing gaze behavior Journal Article In: Attention, Perception, and Psychophysics, vol. 79, no. 1, pp. 154–168, 2017. @article{Cornelissen2017, People have an amazing ability to identify objects and scenes with only a glimpse. How automatic is this scene and object identification? Are scene and object semantics-let alone their semantic congruity-processed to a degree that modulates ongoing gaze behavior even if they are irrelevant to the task at hand? Objects that do not fit the semantics of the scene (e.g., a toothbrush in an office) are typically fixated longer and more often than objects that are congruent with the scene context. In this study, we overlaid a letter T onto photographs of indoor scenes and instructed participants to search for it. Some of these background images contained scene-incongruent objects. Despite their lack of relevance to the search, we found that participants spent more time in total looking at semantically incongruent compared to congruent objects in the same position of the scene. Subsequent tests of explicit and implicit memory showed that participants did not remember many of the inconsistent objects and no more of the consistent objects. We argue that when we view natural environments, scene and object relationships are processed obligatorily, such that irrelevant semantic mismatches between scene and object identity can modulate ongoing eye-movement behavior. |
Benjamin W. Corrigan; Roberto A. Gulli; Guillaume Doucet; Julio C. Martinez-Trujillo Characterizing eye movement behaviors and kinematics of non-human primates during virtual navigation tasks Journal Article In: Journal of Vision, vol. 17, no. 12, pp. 1–22, 2017. @article{Corrigan2017, Virtual environments (VE) allow testing complex behaviors in naturalistic settings by combining highly controlled visual stimuli with spatial navigation and other cognitive tasks. They also allow for the recording of eye movements using high-precision eye tracking techniques, which is important in electrophysiological studies examining the response properties of neurons in visual areas of nonhuman primates. However, during virtual navigation, the pattern of retinal stimulation can be highly dynamic which may influence eye movements. Here we examine whether and how eye movement patterns change as a function of dynamic visual stimulation during virtual navigation tasks, relative to standard oculomotor tasks. We trained two rhesus macaques to use a joystick to navigate in a VE to complete two tasks. To contrast VE behavior with classic measurements, the monkeys also performed a simple Cued Saccade task. We used a robust algorithm for rapid classification of saccades, fixations, and smooth pursuits. We then analyzed the kinematics of saccades during all tasks, and specifically during different phases of the VE tasks. We found that fixation to smooth pursuit ratios were smaller in VE tasks (4:5) compared to the Cued Saccade task (7:1), reflecting a more intensive use of smooth pursuit to foveate targets in VE than in a standard visually guided saccade task or during spontaneous fixations. Saccades made to rewarded targets (exploitation) tended to have increased peak velocities compared to saccades made to unrewarded objects (exploration). VE exploitation saccades were 6% slower than saccades to discrete targets in the Cued Saccade task. Virtual environments represent a technological advance in experimental design for nonhuman primates. Here we provide a framework to study the ways that eye movements change between and within static and dynamic displays. |
Francisco M. Costela; Sidika Kajtezovic; Russell L. Woods The preferred retinal locus used to watch videos Journal Article In: Investigative Ophthalmology & Visual Science, vol. 58, no. 14, pp. 6073–6081, 2017. @article{Costela2017a, Purpose: Eccentric viewing is a common strategy used by people with central vision loss (CVL) to direct the eye such that the image falls onto functioning peripheral retina, known as the preferred retinal locus (PRL). It has been long acknowledged that we do not know whether the PRL used in a fixation test is also used when performing tasks. We present an innovative method to determine whether the same PRL observed during a fixation task was used to watch videos and whether poor resolution affects gaze location.; Methods: The gaze of a group of 60 normal vision (NV) observers was used to define a democratic center of interest (COI) of video clips from movies and television. For each CVL participant (N = 20), we computed the gaze offsets from the COI across the video clips. The distribution of gaze offsets of the NV participants was used to define the limits of NV behavior. If the gaze offset was within this 95% degree confidence interval, we presumed that the same PRL was used for fixation and video watching. Another 15 NV participants watched the video clips with various levels of defocus blur.; Results: CVL participants had wider gaze-offset distributions than NV participants (P < 0.001). Gaze offsets of 18/20 CVL participants were outside the NV confidence interval. Further, none of the 15 NV participants watching the same videos with spherical defocus blur had a gaze offset that was decentered (outside the NV confidence interval), suggesting that resolution was not the problem.; Conclusions: This indicates that many CVL participants were using a PRL to view videos that differed from that found with a fixation task and that it was not caused by poor resolution alone. The relationship between these locations needs further investigation. |
Jenna Course-Choi; Harry Saville; Nazanin Derakshan The effects of adaptive working memory training and mindfulness meditation training on processing efficiency and worry in high worriers Journal Article In: Behaviour Research and Therapy, vol. 89, pp. 1–13, 2017. @article{CourseChoi2017, Worry is the principle characteristic of generalised anxiety disorder, and has been linked to deficient attentional control, a main function of working memory (WM). Adaptive WM training and mindfulness meditation practice (MMP) have both shown potential to increase attentional control. The present study hence investigates the individual and combined effects of MMP and a dual adaptive n-back task on a non-clinical, randomised sample of high worriers. 60 participants were tested before and after seven days of training. Assessment included self-report questionnaires, as well as performance tasks measuring attentional control and working memory capacity. Combined training resulted in continued reduction in worry in the week after training, highlighting the potential of utilising n-back training as an adjunct to established clinical treatment. Engagement with WM training correlated with immediate improvements in attentional control and resilience, with worry decreasing over time. Implications of these findings and suggestions for future research are discussed. |
Matt Craddock; Frank Oppermann; Matthias M. Müller; Jasna Martinovic Modulation of microsaccades by spatial frequency during object categorization Journal Article In: Vision Research, vol. 130, pp. 48–56, 2017. @article{Craddock2017, The organization of visual processing into a coarse-to-fine information processing based on the spatial frequency properties of the input forms an important facet of the object recognition process. During visual object categorization tasks, microsaccades occur frequently. One potential functional role of these eye movements is to resolve high spatial frequency information. To assess this hypothesis, we examined the rate, amplitude and speed of microsaccades in an object categorization task in which participants viewed object and non-object images and classified them as showing either natural objects, man-made objects or non-objects. Images were presented unfiltered (broadband; BB) or filtered to contain only low (LSF) or high spatial frequency (HSF) information. This allowed us to examine whether microsaccades were modulated independently by the presence of a high-level feature – the presence of an object – and by low-level stimulus characteristics – spatial frequency. We found a bimodal distribution of saccades based on their amplitude, with a split between smaller and larger microsaccades at 0.4° of visual angle. The rate of larger saccades (⩾0.4°) was higher for objects than non-objects, and higher for objects with high spatial frequency content (HSF and BB objects) than for LSF objects. No effects were observed for smaller microsaccades (<0.4°). This is consistent with a role for larger microsaccades in resolving HSF information for object identification, and previous evidence that more microsaccades are directed towards informative image regions. |
Jason L. Chan; Michael J. Koval; Kevin D. Johnston; Stefan Everling Neural correlates for task switching in the macaque superior colliculus Journal Article In: Journal of Neurophysiology, vol. 118, pp. 2156–2170, 2017. @article{Chan2017, Successful task switching requires a network of brain areas to select, maintain, implement, and execute the appropriate task. Although frontoparietal brain areas are thought to play a critical role in task switching by selecting and encoding task rules and exerting top-down control, how brain areas closer to the execution of tasks participate in task switching is unclear. The superior colliculus (SC) integrates information from various brain areas to generate saccades and is likely influenced by task switching. Here, we investigated switch costs in nonhuman primates and their neural correlates in the activity of SC saccade-related neurons in monkeys performing cued, randomly interleaved pro- and anti-saccade trials. We predicted that behavioral switch costs would be associated with differential modulations of SC activity in trials on which the task was switched vs. repeated, with activity on the current trial resembling that associated with the task set of the previous trial when a switch occurred. We observed both error rate and reaction time switch costs and changes in the discharge rate and timing of activity in SC neurons between switch and repeat trials. These changes were present later in the task only after fixation on the cue stimuli but before saccade onset. These results further establish switch costs in macaque monkeys and suggest that SC activity is modulated by task-switching processes in a manner inconsistent with the concept of task set inertia. |
Vassiki Chauhan; Matteo Visconti di Oleggio Castello; Alireza Soltani; M. Ida Gobbini Social saliency of the cue slows attention shifts Journal Article In: Frontiers in Psychology, vol. 8, pp. 738, 2017. @article{Chauhan2017, Eye gaze is a powerful cue that indicates where another person's attention is directed in the environment. Seeing another person's eye gaze shift spontaneously and reflexively elicits a shift of one's own attention to the same region in space. Here, we investigated whether reallocation of attention in the direction of eye gaze is modulated by personal familiarity with faces. On the one hand, the eye gaze of a close friend should be more effective in redirecting our attention as compared to the eye gaze of a stranger. On the other hand, the social relevance of a familiar face might itself hold attention and, thereby, slow lateral shifts of attention. To distinguish between these possibilities, we measured the efficacy of the eye gaze of personally familiar and unfamiliar faces as directional attention cues using adapted versions of the Posner paradigm with saccadic and manual responses. We found that attention shifts were slower when elicited by a perceived change in the eye gaze of a familiar individual as compared to attention shifts elicited by unfamiliar faces at short latencies (100 ms). We also measured simple detection of change in direction of gaze in personally familiar and unfamiliar faces to test whether slower attention shifts were due to slower detection. Participants detected changes in eye gaze faster for familiar faces than for unfamiliar faces. Our results suggest that personally familiar faces briefly hold attention due to their social relevance, thereby slowing shifts of attention, even though the direction of eye movements are detected faster in familiar faces. |
Fuguo Chen; Jie Liu; Shuanghong Chen; Hong Chen; Xiao Gao Eye movement study on attention bias to body height stimuli in height dissatisfied males Journal Article In: Frontiers in Psychology, vol. 8, pp. 2209, 2017. @article{Chen2017, The present study investigated attention bias in response to height-related words among young men in China. 47 [26 high height dissatisfied (HHD) and 21 low height dissatisfied (LHD)] men performed a dot-probe task. Eye movement (EM) recordings showed that compared to LHD men, HHD men had an avoidance bias in response to height-related words, which was revealed by less frequent first fixations on both tall-related and short-related words, and showed significantly shorter first fixations on short-related words. There was no other significant difference in EM indices (i.e., first fixation latency and gaze duration) between two groups. In addition, HHD participants were significantly slower than LHD participants when responding to probes preceded by short-related words, while there was no difference when probes were preceded by tall-related or neutral words. In sum, the present results indicate that HHD men selectively avoid cues related to short height. |
Jing Chen; Matteo Valsecchi; Karl R. Gegenfurtner Attention is allocated closely ahead of the target during smooth pursuit eye movements: Evidence from EEG frequency tagging Journal Article In: Neuropsychologia, vol. 102, pp. 206–216, 2017. @article{Chen2017c, It is under debate whether attention during smooth pursuit is centered right on the pursuit target or allocated preferentially ahead of it. Attentional deployment was previously probed using a secondary task, which might have altered attention allocation and led to inconsistent findings. We measured frequency-tagged steady-state visual evoked potentials (SSVEP) to measure attention allocation in the absence of any secondary probing task. The observers pursued a moving dot while stimuli flickering at different frequencies were presented at various locations ahead or behind the pursuit target. We observed a significant increase in EEG power at the flicker frequency of the stimulus in front of the pursuit target, compared to the frequency of the stimulus behind. When testing many different locations, we found that the enhancement was detectable up to about 1.5° ahead during pursuit, but vanished by 3.5°. In a control condition using attentional cueing during fixation, we did observe an enhanced EEG response to stimuli at this eccentricity, indicating that the focus of attention during pursuit is narrower than allowed for by the resolution of the attentional system. In a third experiment, we ruled out the possibility that the SSVEP enhancement was a byproduct of the catch-up saccades occurring during pursuit. Overall, we showed that attention is on average allocated ahead of the pursuit target during smooth pursuit. EEG frequency tagging seems to be a powerful technique that allows for the investigation of attention/perception implicitly when an overt task would be confounding. |
Mo Chen; Yuan-Zheng Wang; Chen-Chen Ma; Qi-Ze Li; Han Zhou; Jie Fu; Qian-Qian Yang; Yong-Mei Zhang; Yu Liu; Jun-Li Cao Empathy skill-dependent modulation of working memory by painful scene Journal Article In: Scientific Reports, vol. 7, pp. 4527, 2017. @article{Chen2017e, As an important online information retaining and processing function, working memory plays critical roles in many other cognitive functions. Several long-term factors, such as age, addiction and diseases, have been affirmed to impair working memory, but whether or how the short-term factors, like painful stimuli or emotions, regulate the human working memory ability is not well explored. Here we investigated the influences of empathic pain on upcoming working memory and existing working memory, by presenting human subjects with the pictures depicting painful or neutral scene. After separating the subjects into two groups, the more empathic group and relatively indifferent group, according to a well-accepted questionnaire (the Interpersonal Reactivity Index (IRI)), the modulatory effect emerged. Empathic pain might exerted either a facilitating effect or an impairing effect, which was closely correlated with the personal empathy skills. Meanwhile, different aspects of subjects' empathy traits exerted distinct effects, and female subjects were more vulnerable than male subjects. Present study reveals a new modulatory manner of the working memory, via empathy skill-dependent painful experience. |
Nigel T. M. Chen; Julian Basanovic; Lies Notebaert; Colin MacLeod; Patrick J. F. Clarke Attentional bias mediates the effect of neurostimulation on emotional vulnerability Journal Article In: Journal of Psychiatric Research, vol. 93, pp. 12–19, 2017. @article{Chen2017b, Transcranial direct current stimulation (tDCS) is a neuromodulatory technique which has garnered recent interest in the potential treatment for emotion-based psychopathology. While accumulating evidence suggests that tDCS may attenuate emotional vulnerability, critically, little is known about underlying mechanisms of this effect. The present study sought to clarify this by examining the possibility that tDCS may affect emotional vulnerability via its capacity to modulate attentional bias towards threatening information. Fifty healthy participants were randomly assigned to receive either anodal tDCS (2 mA/min) stimulation to the left dorsolateral prefrontal cortex (DLPFC), or sham. Participants were then eye tracked during a dual-video stressor task designed to elicit emotional reactivity, while providing a concurrent in-vivo measure of attentional bias. Greater attentional bias towards threatening information was associated with greater emotional reactivity to the stressor task. Furthermore, the active tDCS group showed reduced attentional bias to threat, compared to the sham group. Importantly, attentional bias was found to statistically mediate the effect of tDCS on emotional reactivity, while no direct effect of tDCS on emotional reactivity was observed. The findings are consistent with the notion that the effect of tDCS on emotional vulnerability may be mediated by changes in attentional bias, holding implications for the application of tDCS in emotion-based psychopathology. The findings also highlight the utility of in-vivo eye tracking measures in the examination of the mechanisms associated with DLPFC neuromodulation in emotional vulnerability. |