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2024 |
Eser Sendesen; Didem Turkyilmaz Listening handicap in tinnitus patients by controlling extended high frequencies - Effort or fatigue? Journal Article In: Auris Nasus Larynx, vol. 51, no. 1, pp. 198–205, 2024. @article{Sendesen2024,Objective: In previous studies, the results regarding the presence of listening effort or fatigue in tinnitus patients were inconsistent. The reason for this inconsistency could be that extended high frequencies, which can cause listening handicap, were not considered. Therefore, this study aimed to evaluate the listening skills in tinnitus patients by matching the hearing thresholds at all frequencies, including the extended high frequency. Methods: Eighteen chronic tinnitus patients and thirty matched healthy controls having normal pure-tone average with symmetrical hearing thresholds was included. Subjects were evaluated with 0.125-20 kHz pure-tone audiometry, Montreal cognitive assessment test (MoCA), Tinnitus Handicap Inventory (THI), Matrix Test, Pupillometry. Results: Pupil dilatation in the 'coding' phase of the sentence presented in tinnitus patients was less than in the control group (p<0.05). There was no difference between the groups for Matrix test scores (p> 0.05) Also, there was no statistically significant correlation between THI and Pupillometry components nor between MoCA (p>0.05). Conclusion: The results were interpreted for potential listening fatigue in tinnitus patients. Considering the possible listening handicap in tinnitus patients, reducing the listening difficulties especially in noisy environments, can be added to the goals of tinnitus therapy protocols. |
Arthur Pabst; Zoé Bollen; Nicolas Masson; Mado Gautier; Christophe Geus; Pierre Maurage Altered attentional processing of facial expression features in severe alcohol use disorder: An eye-tracking study. Journal Article In: Journal of Psychopathology and Clinical Science, vol. 133, no. 1, pp. 103–114, 2024. @article{Pabst2024,Social cognition impairments, and notably emotional facial expression (EFE) recognition difficulties, as well as their functional and clinical correlates, are increasingly documented in severe alcohol use disorder (SAUD). However, insights into their underlying mechanisms are lacking. Here, we tested if SAUD was associated with alterations in the attentional processing of EFEs. In a preregistered study, 40 patients with SAUD and 40 healthy controls (HCs) had to identify the emotional expression conveyed by faces while having their gaze recorded by an eye-tracker. We assessed indices of initial (first fixation locations) and later (number of fixations and dwell-time) attention with reference to regions of interest corresponding to the eyes, mouth, and nose, which carry key information for EFE recognition. We centrally found that patients had less first fixations to key facial features in general, as well as less fixations and dwell time to the eyes specifically, relative to the rest of the face, compared to controls. These effects were invariant across emotional expressions. Additional exploratory analyses revealed that patients with SAUD had a less structured viewing pattern than controls. These results offer novel, direct, evidence that patients with SAUD's socioaffective difficulties already emerge at the facial attentional pro- cessing stage, along with precisions regarding the nature and generalizability of the effects. Potential implications for the mechanistic conceptualization and treatment of social cognition difficulties in SAUD are discussed. |
Claudio M. Privitera; Sean Noah; Thom Carney; Stanley A. Klein; Agatha Lenartowicz; Stephen P. Hinshaw; James T. McCracken; Joel T. Nigg; Sarah L. Karalunas; Rory C. Reid; Mercedes T. Oliva; Samantha S. Betts; Gregory V. Simpson Pupillary dilations in a Target/Distractor visual task paradigm and attention deficit hyperactivity disorder (ADHD) Journal Article In: Neuroscience Letters, vol. 818, pp. 1–6, 2024. @article{Privitera2024,ADHD is a neurocognitive disorder characterized by attention difficulties, hyperactivity, and impulsivity, often persisting into adulthood with substantial personal and societal consequences. Despite the importance of neurophysiological assessment and treatment monitoring tests, their availability outside of research settings remains limited. Cognitive neuroscience investigations have identified distinct components associated with ADHD, including deficits in sustained attention, inefficient enhancement of attended Targets, and altered suppression of ignored Distractors. In this study, we examined pupil activity in control and ADHD subjects during a sustained visual attention task specifically designed to evaluate the mechanisms underlying Target enhancement and Distractor suppression. Our findings revealed some distinguishing factors between the two groups which we discuss in light of their neurobiological implications. |
Yawen Guo; Jon D. Elhai; Christian Montag; Yang Wang; Haibo Yang Problematic mobile gamers have attention bias toward game social information Journal Article In: Computers in Human Behavior, vol. 152, pp. 1–13, 2024. @article{Guo2024,Attention bias towards game information influences players' problematic mobile game usage (PMGU). Social experience is an important part of games. This study aimed to explore attention bias mechanisms of problematic mobile gamers for game social information. Experiments 1 and 2 recruited 68 participants (19.82 ± 1.38 years), and used the dot-probe task to investigate attention bias among problematic mobile gamers. Results showed that reaction time and trial-level bias scores (TL-BS) of socially anxious problematic mobile gamers toward game social information were not significantly different from those toward game non-social information. Experiment 3 recruited 35 participants (19.71 ± 1.18 years), and combined eye-tracking technology with the dot-probe task to investigate problematic mobile gamers' attention bias and dynamic visual processing. Results of this last experiment showed that socially anxious problematic mobile gamers' first fixation latency for game social information was significantly shorter than for game non-social information, and their gaze duration and total fixation duration were significantly longer for social than game non-social information. In summary, the eye tracking experiments give support for the idea that socially anxious problematic mobile gamers show attention bias towards game social information, which is presented as the vigilance-maintenance pattern. |
Xu Liu; Yu Li; Lihua Xu; Tianhong Zhang; Huiru Cui; Yanyan Wei; Mengqing Xia; Wenjun Su; Yingying Tang; Xiaochen Tang; Dan Zhang; Lothar Spillmann; Ian Max Andolina; Niall McLoughlin; Wei Wang; Jijun Wang Spatial and temporal abnormalities of spontaneous fixational saccades and their correlates with positive and cognitive symptoms in schizophrenia Journal Article In: Schizophrenia Bulletin, vol. 50, no. 1, pp. 78–88, 2024. @article{Liu2024,BACKGROUND AND HYPOTHESIS: Visual fixation is a dynamic process, with the spontaneous occurrence of microsaccades and macrosaccades. These fixational saccades are sensitive to the structural and functional alterations of the cortical-subcortical-cerebellar circuit. Given that dysfunctional cortical-subcortical-cerebellar circuit contributes to cognitive and behavioral impairments in schizophrenia, we hypothesized that patients with schizophrenia would exhibit abnormal fixational saccades and these abnormalities would be associated with the clinical manifestations. STUDY DESIGN: Saccades were recorded from 140 drug-naïve patients with first-episode schizophrenia and 160 age-matched healthy controls during ten separate trials of 6-second steady fixations. Positive and negative symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). Cognition was assessed using the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB). STUDY RESULTS: Patients with schizophrenia exhibited fixational saccades more vertically than controls, which was reflected in more vertical saccades with angles around 90° and a greater vertical shift of horizontal saccades with angles around 0° in patients. The fixational saccades, especially horizontal saccades, showed longer durations, faster peak velocities, and larger amplitudes in patients. Furthermore, the greater vertical shift of horizontal saccades was associated with higher PANSS total and positive symptom scores in patients, and the longer duration of horizontal saccades was associated with lower MCCB neurocognitive composite, attention/vigilance, and speed of processing scores. Finally, based solely on these fixational eye movements, a K-nearest neighbors model classified patients with an accuracy of 85%. Conclusions: Our results reveal spatial and temporal abnormalities of fixational saccades and suggest fixational saccades as a promising biomarker for cognitive and positive symptoms and for diagnosis of schizophrenia. |
Natalia Melnik; Stefan Pollmann Saccadic re-referencing training with gaze-contingent FRL-'fixation': Effects of scotoma type and size adaptation Journal Article In: Vision Research, vol. 214, no. 214, pp. 1–11, 2024. @article{Melnik2024,Foveal vision loss makes the fovea as saccadic reference point maladaptive. Training programs have been proposed that shift the saccadic reference point from the fovea to an extrafoveal location, just outside the area of vision loss. We used a visual search task to train normal-sighted participants to fixate target items with a predetermined 'forced retinal location' (FRL) adjacent to a simulated central scotoma. We found that training was comparatively successful for scotomata that had either a sharp or blurry demarcation from the background. Completing the task with sharp-edged scotoma resulted in overall higher training gains. Training with blurry-edged scotoma, however, yielded overall better results when scotoma size was increased after training and participants needed to adapt to a more eccentric FRL, as may be necessary in patients with progressive degenerative eye diseases. |
Kateryna Melnyk; Lee Friedman; Oleg V. Komogortsev What can entropy metrics tell us about the characteristics of ocular fixation trajectories? Journal Article In: PloS ONE, vol. 19, no. 1, pp. 1–45, 2024. @article{Melnyk2024,In this study, we provide a detailed analysis of entropy measures calculated for fixation eye movement trajectories from the three different datasets. We employed six key metrics (Fuzzy, Increment, Sample, Gridded Distribution, Phase, and Spectral Entropies). We calculate these six metrics on three sets of fixations: (1) fixations from the GazeCom dataset, (2) fixations from what we refer to as the "Lund" dataset, and (3) fixations from our own research laboratory ("OK Lab" dataset). For each entropy measure, for each dataset, we closely examined the 36 fixations with the highest entropy and the 36 fixations with the lowest entropy. From this, it was clear that the nature of the information from our entropy metrics depended on which dataset was evaluated. These entropy metrics found various types of misclassified fixations in the GazeCom dataset. Two entropy metrics also detected fixation with substantial linear drift. For the Lund dataset, the only finding was that low spectral entropy was associated with what we call "bumpy" fixations. These are fixations with low-frequency oscillations. For the OK Lab dataset, three entropies found fixations with high-frequency noise which probably represent ocular microtremor. In this dataset, one entropy found fixations with linear drift. The between-dataset results are discussed in terms of the number of fixations in each dataset, the different eye movement stimuli employed, and the method of eye movement classification. |
Nora Geiser; Brigitte Charlotte Kaufmann; Samuel Elia Johannes Knobel; Dario Cazzoli; Tobias Nef; Thomas Nyffeler Comparison of uni- and multimodal motion stimulation on visual neglect: A proof-of-concept study Journal Article In: Cortex, vol. 171, pp. 194–203, 2024. @article{Geiser2024,Spatial neglect is characterized by the failure to attend stimuli presented in the contralesional space. Typically, the visual modality is more severely impaired than the auditory one. This dissociation offers the possibility of cross-modal interactions, whereby auditory stimuli may have beneficial effects on the visual modality. A new auditory motion stimulation method with music dynamically moving from the right to the left hemispace has recently been shown to improve visual neglect. The aim of the present study was twofold: a) to compare the effects of unimodal auditory against visual motion stimulation, i.e., smooth pursuit training, which is an established therapeutical approach in neglect therapy and b) to explore whether a combination of auditory + visual motion stimulation, i.e., multimodal motion stimulation, would be more effective than unimodal auditory or visual motion stimulation. 28 patients with left-sided neglect due to a first-ever, right-hemispheric subacute stroke were included. Patients either received auditory, visual, or multimodal motion stimulation. The between-group effect of each motion stimulation condition as well as a control group without motion stimulation was investigated by means of a one-way ANOVA with the patient's visual exploration behaviour as an outcome variable. Our results showed that unimodal auditory motion stimulation is equally effective as unimodal visual motion stimulation: both interventions significantly improved neglect compared to the control group. Multimodal motion stimulation also significantly improved neglect, however, did not show greater improvement than unimodal auditory or visual motion stimulation alone. Besides the established visual motion stimulation, this proof-of-concept study suggests that auditory motion stimulation seems to be an alternative promising therapeutic approach to improve visual attention in neglect patients. Multimodal motion stimulation does not lead to any additional therapeutic gain. In neurorehabilitation, the implementation of either auditory or visual motion stimulation seems therefore reasonable. |
Vaibhav A. Diwadkar; Deborah Kashy; Jacqueline Bao; Katharine N. Thakkar Abnormal oculomotor corollary discharge signaling as a trans-diagnostic mechanism of psychosis Journal Article In: Schizophrenia Bulletin, pp. 1–11, 2024. @article{Diwadkar2024,Background and Hypothesis: Corollary discharge (CD) signals are “copies” of motor signals sent to sensory areas to predict the corresponding input. They are a posited mechanism enabling one to distinguish actions generated by oneself vs external forces. Consequently, altered CD is a hypothesized mechanism for agency disturbances in psychosis. Previous studies have shown a decreased influence of CD signals on visual perception in individuals with schizophrenia—particularly in those with more severe positive symptoms. We therefore hypothesized that altered CD may be a trans-diagnostic mechanism of psychosis. Study Design: We examined oculomotor CD (using the blanking task) in 49 participants with schizophrenia or schizoaffective disorder (SZ), 36 bipolar participants with psychosis (BPP), and 40 healthy controls (HC). Participants made a saccade to a visual target. Upon saccade initiation, the target disappeared and reappeared at a horizontally displaced position. Participants indicated the direction of displacement. With intact CD, participants can make accurate perceptual judgements. Otherwise, participants may use saccade landing site as a proxy of pre-saccadic target to inform perception. Thus, multi-level modeling was used to examine the influence of target displacement and saccade landing site on displacement judgements. Study Results: SZ and BPP were equally less sensitive to target displacement than HC. Moreover, regardless of diagnosis, SZ and BPP with more severe positive symptoms were more likely to rely on saccade landing site. Conclusions: These results suggest that altered CD may be a trans-diagnostic mechanism of psychosis. |
Palpolage Don Shehan Hiroshan Gunawardane; Raymond Robert MacNeil; Leo Zhao; James Theodore Enns; Clarence Wilfred Silva; Mu Chiao A fusion algorithm based on a constant velocity model for improving the measurement of saccade parameters with electrooculography Journal Article In: Sensors, vol. 24, no. 540, pp. 1–19, 2024. @article{Gunawardane2024,Abstract: Electrooculography (EOG) serves as a widely employed technique for tracking saccadic eye movements in a diverse array of applications. These encompass the identification of various medical conditions and the development of interfaces facilitating human–computer interaction. Nonetheless, EOG signals are often met with skepticism due to the presence of multiple sources of noise interference. These sources include electroencephalography, electromyography linked to facial and extraocular muscle activity, electrical noise, signal artifacts, skin-electrode drifts, impedance fluctuations over time, and a host of associated challenges. Traditional methods of addressing these issues, such as bandpass filtering, have been frequently utilized to overcome these challenges but have the associated drawback of altering the inherent characteristics of EOG signals, encompassing their shape, magnitude, peak velocity, and duration, all of which are pivotal parameters in research studies. In prior work, several model-based adaptive denoising strategies have been introduced, incorporating mechanical and electrical model-based state estimators. However, these approaches are really complex and rely on brain and neural control models that have difficulty processing EOG signals in real time. In this present investigation, we introduce a real-time denoising method grounded in a constant velocity model, adopting a physics-based model-oriented approach. This approach is underpinned by the assumption that there exists a consistent rate of change in the cornea-retinal potential during saccadic movements. Empirical findings reveal that this approach remarkably preserves EOG saccade signals, resulting in a substantial enhancement of up to 29% in signal preservation during the denoising process when compared to alternative techniques, such as bandpass filters, constant acceleration models, and model-based fusion methods. WABBLE: |
Reza Azadi; Alex O. Holcombe; Jay A. Edelman Hypometria of saccadic eye movements to targets in rapid circular motion Journal Article In: Journal of Vision, vol. 24, no. 1, pp. 1–19, 2024. @article{Azadi2024,Saccades to objects moving on a straight trajectory take the velocity of the object into account. However, it is not known whether saccades can compensate for curved trajectories, nor is it known how they are affected by high target speeds. In Experiment 1, participants made a saccade in a delayed saccade task to a target moving in a circular trajectory. Surprisingly, saccades to high-speed moving targets were severely hypometric, with gains of only ∼55% for trajectories of the largest angular speed (2 revolutions per second) and eccentricity (12°). They also had unusually low peak velocities. In Experiment 2, the target jumped along a circular path around a central fixation point. Hypometria was still severe, except for very large jumps. Experiment 3 was like Experiment 1, except that a landmark was positioned on the trajectory of the target, and participants were instructed to make a saccade to the landmark or to its memorized location. This ameliorated hypometria considerably. Given the delayed nature of the tasks of Experiments 1 and 2, participants had considerable time to program a voluntary saccade to a location on the trajectory, if not to the rapidly moving target itself. Nevertheless, the abnormal saccade properties indicate that motor programming was compromised. These results indicate that motor output can be inextricably bound to sensory input to its detriment, even during a highly voluntary motor act; that apparent motion can produce this behavior; and that such abnormal saccades can be "rescued" by the presence of a stable visual goal. |
Larisa-maria Dinu; Alexandra-Livia Georgescu; Samriddhi N. Singh; Nicola C. Byrom; G. Overton; Bryan F. Singer; Eleanor J. Dommett Sign-tracking and goal-tracking in humans: Utilising eye-tracking in clinical and non-clinical populations Journal Article In: Behavioural Brain Research, vol. 461, pp. 1–10, 2024. @article{Dinu2024,Background: In Pavlovian conditioning, learned behaviour varies according to the perceived value of environmental cues. For goal-trackers (GT), the cue merely predicts a reward, whilst for sign-trackers (ST), the cue holds incentive value. The sign-tracking/goal-tracking model is well-validated in animals, but translational work is lacking. Despite the model's relevance to several conditions, including attention deficit hyperactivity disorder (ADHD), we are unaware of any studies that have examined the model in clinical populations. Methods: The current study used an eye-tracking Pavlovian conditioning paradigm to identify ST and GT in non- clinical (N = 54) and ADHD (N = 57) participants. Eye movements were recorded whilst performing the task. Dwell time was measured for two areas of interest: sign (i.e., cue) and goal (i.e., reward), and an eye-gaze index (EGI) was computed based on the dwell time sign-to-goal ratio. Higher EGI values indicate sign-tracking behaviour. ST and GT were determined using median and tertiary split approaches in both samples. Results: Despite greater propensity for sign-tracking in those with ADHD, there was no significant difference between groups. The oculomotor conditioned response was reward-specific (CS+) and present, at least partly, from the start of the task indicating dispositional and learned components. There were no differences in externalising behaviours between ST and GT for either sample. Conclusions: Sign-tracking is associated with CS+ trials only. There may be both dispositional and learned components to sign-tracking, potentially more common in those with ADHD. This holds translational potential for understanding individual differences in reward-learning. |
Hong Zhou; Luhua Wei; Yanyan Jiang; Xia Wang; Yunchuang Sun; Fan Li; Jing Chen; Wei Sun; Lin Zhang; Guiping Zhao; Zhaoxia Wang Abnormal Ocular Movement in the Early Stage of Multiple-System Atrophy With Predominant Parkinsonism Distinct From Parkinson's Disease Journal Article In: Journal of Clinical Neurology, vol. 20, no. 1, pp. 37–45, 2024. @article{Zhou2024,Background and Purpose The eye-movement examination can be applied as a noninvasive method to identify multiple-system atrophy (MSA). Few studies have investigated eye movements during the early stage of MSA with predominant parkinsonism (MSA-P). We aimed to determine the characteristic oculomotor changes in the early stage of MSA-P. Methods We retrospectively selected 17 patients with MSA-P and 40 with Parkinson's disease (PD) with disease durations of less than 2 years, and 40 age-matched healthy controls (HCs). Oculomotor performance in the horizontal direction was measured in detail using videonystagmography. Results We found that the proportions of patients with MSA-P and PD exhibiting abnormal eye movements were 82.4% and 77.5%, respectively, which were significantly higher than that in the HCs (47.5%, p<0.05). Compared with HCs, patients with MSA-P presented significantly higher abnormal proportions of fixation and gaze-holding (17.6% vs. 0%), without-fixation (47.1% vs. 0%), prolonged latency in reflexive saccades (29.4% vs. 5.0%), memory-guided saccades (93.3% vs. 10.0%), and catch-up saccades in smooth-pursuit movement (SPM, 41.2% vs. 0) (all p<0.05). Compared with those with PD, patients with MSA-P presented a signifi- cantly higher proportion of catch-up saccades in SPM (41.2% vs. 2.5%, p<0.001). Conclusions MSA-P presented the characteristic of catch-up saccades in SPM in the early stage, which may provide some value in differentiating MSA-P from PD. |
Inbal Ziv; Inbar Avni; Ilan Dinstein; Gal Meiri; Yoram S. Bonneh Oculomotor randomness is higher in autistic children and increases with the severity of symptoms Journal Article In: Autism Research, pp. 1–17, 2024. @article{Ziv2024,A variety of studies have suggested that at least some children with autism spectrum disorder (ASD) view the world differently. Differences in gaze patterns as measured by eye tracking have been demonstrated during visual exploration of images and natural viewing of movies with social content. Here we analyzed the temporal randomness of saccades and blinks during natural viewing of movies, inspired by a recent measure of “randomness” applied to micro-movements of the hand and head in ASD (Torres et al., 2013; Torres & Denisova, 2016). We analyzed a large eye-tracking dataset of 189 ASD and 41 typically developing (TD) children (1–11 years old) who watched three movie clips with social content, each repeated twice. We found that oculomotor measures of randomness, obtained from gamma parameters of inter-saccade intervals (ISI) and blink duration distributions, were significantly higher in the ASD group compared with the TD group and were correlated with the ADOS comparison score, reflecting increased “randomness” in more severe cases. Moreover, these measures of randomness decreased with age, as well as with higher cognitive scores in both groups and were consistent across repeated viewing of each movie clip. Highly “random” eye movements in ASD children could be associated with high “neural variability” or noise, poor sensory-motor control, or weak engagement with the movies. These findings could contribute to the future development of oculomotor biomarkers as part of an integrative diagnostic tool for ASD. |
Zoé Bollen; Arthur Pabst; Nicolas Masson; Reinout W. Wiers; Matt Field; Pierre Maurage Craving modulates attentional bias towards alcohol in severe alcohol use disorder: An eye-tracking study Journal Article In: Addiction, vol. 119, no. 1, pp. 1–11, 2024. @article{Bollen2024,Background and aims: Competing models disagree on three theoretical questions regarding alcohol-related attentional bias (AB), a key process in severe alcohol use disorder (SAUD): (1) is AB more of a trait (fixed, associated with alcohol use severity) or state (fluid, associated with momentary craving states) characteristic of SAUD; (2) does AB purely reflect the over-activation of the reflexive/reward system or is it also influenced by the activity of the reflective/control system and (3) does AB rely upon early or later processing stages? We addressed these issues by investigating the time-course of AB and its modulation by subjective craving and cognitive load in SAUD. Design: A free-viewing eye-tracking task, presenting pictures of alcoholic and non-alcoholic beverages, combined with a concurrent cognitive task with three difficulty levels. Setting: A laboratory setting in the detoxification units of three Belgian hospitals. Participants: We included 30 patients with SAUD self-reporting craving at testing time, 30 patients with SAUD reporting a total absence of craving and 30 controls matched on sex and age. All participants from SAUD groups met the DSM-5 criteria for SAUD. Measurements: We assessed AB through early and late eye-tracking indices. We evaluated the modulation of AB by craving (comparison between patients with/without craving) and cognitive load (variation of AB with the difficulty level of the concurrent task). Findings: Dwell time measure indicated that SAUD patients with craving allocated more attention towards alcohol-related stimuli than patients without craving (P < 0.001 |
Andy Brendler; Max Schneider; Immanuel G. Elbau; Rui Sun; Taechawidd Nantawisarakul; Dorothee Pöhlchen; Tanja Brückl; A. K. Brem; E. B. Binder; A. Erhardt; J. Fietz; N. C. Grandi; Y. Kim; S. Ilić-Ćoćić; L. Leuchs; S. Lucae; T. Namendorf; J. Pape; L. Schilbach; I. Mücke-Heim; J. Ziebula; Michael Czisch; Philipp G. Sämann; Michael D. Lee; Victor I. Spoormaker In: Scientific Reports, vol. 14, no. 344, pp. 1–11, 2024. @article{Brendler2024,Major depressive disorder (MDD) is a devastating and heterogenous disorder for which there are no approved biomarkers in clinical practice. We recently identified anticipatory hypo-arousal indexed by pupil responses as a candidate mechanism subserving depression symptomatology. Here, we conducted a replication and extension study of these findings. We analyzed a replication sample of 40 unmedicated patients with a diagnosis of depression and 30 healthy control participants, who performed a reward anticipation task while pupil responses were measured. Using a Bayesian modelling approach taking measurement uncertainty into account, we could show that the negative correlation between pupil dilation and symptom load during reward anticipation is replicable within MDD patients, albeit with a lower effect size. Furthermore, with the combined sample of 136 participants (81 unmedicated depressed and 55 healthy control participants), we further showed that reduced pupil dilation in anticipation of reward is inversely associated with anhedonia items of the Beck Depression Inventory in particular. Moreover, using simultaneous fMRI, particularly the right anterior insula as part of the salience network was negatively correlated with depressive symptom load in general and anhedonia items specifically. The present study supports the utility of pupillometry in assessing noradrenergically mediated hypo-arousal during reward anticipation in MDD, a physiological process that appears to subserve anhedonia. |
Laura Nuding; Linda Lukas; Belinda Platt; Gerd Schulte-Körne; Anca Sfärlea Look me in the eyes! A preliminary study on eye-contact in adolescents with anorexia nervosa Journal Article In: European Eating Disorders Review, vol. 32, no. 1, pp. 13–19, 2024. @article{Nuding2024,Objective: Anorexia nervosa (AN) is often associated with impairments in the socio-emotional domain. Avoidance of eye-contact may underlie some of these difficulties and has been found in adults with AN in several studies. This study aimed to clarify whether adolescents with AN also show reduced eye-contact when viewing social stimuli, that is, faces. Methods: In this cross-sectional study, girls aged 12–18 years with AN (n = 38) were compared with a clinical (girls with depression and/or anxiety disorders; n = 30) and a healthy (n = 36) control group. Eye-contact was operationalised as maintenance of visual attention to the eye-area of faces showing different emotional expressions (happy, angry, afraid, sad, neutral), recorded via eye-tracking. Results: Contrary to our expectations, we did not find adolescents with AN to dwell less on the eye-area than control groups; instead, we found preliminary evidence for increased attention to the eye-area in the AN group compared to the healthy control group. Conclusions: The results suggest that reduced eye-contact found in adult AN samples is not (yet) present in adolescents with AN but may develop with the prolonged duration of the disorder. However, replication and longitudinal studies are needed to confirm this assumption. |
Omer Azriel; Gal Arad; Daniel S. Pine; Amit Lazarov; Yair Bar-Haim Attention bias vs. attention control modification for social anxiety disorder: A randomized controlled trial Journal Article In: Journal of Anxiety Disorders, vol. 101, pp. 1–10, 2024. @article{Azriel2024,Gaze-Contingent Music Reward Therapy (GC-MRT) is an eye-tracking-based attention bias modification protocol for social anxiety disorder (SAD) with established clinical efficacy. However, it remains unclear if improvement following GC-MRT hinges on modification of threat-related attention or on more general enhancement of attention control. Here, 50 patients with SAD were randomly allocated to GC-MRT using either threat faces or shapes. Results indicate comparable reductions in social anxiety and co-morbid depression symptoms in the two conditions. Patients in the shapes condition showed a significant increase in attention control and a reduction in attention to both the trained shapes and threat faces, whereas patients in the faces condition showed a reduction in attention to threat faces only. These findings suggest that enhancement of attention control, independent of valence-specific attention modification, may facilitate reduction in SAD symptoms. Alternative interpretations and clinical implications of the current findings are discussed. |
2023 |
M. J. Nelson; S. Moeller; M. Seckin; E. J. Rogalski; M. M. Mesulam; R. S. Hurley The eyes speak when the mouth cannot: Using eye movements to interpret omissions in primary progressive aphasia Journal Article In: Neuropsychologia, vol. 184, pp. 1–9, 2023. @article{Nelson2023,Though it may seem simple, object naming is a complex multistage process that can be impaired by lesions at various sites of the language network. Individuals with neurodegenerative disorders of language, known as primary progressive aphasias (PPA), have difficulty with naming objects, and instead frequently say “I don't know” or fail to give a vocal response at all, known as an omission. Whereas other types of naming errors (paraphasias) give clues as to which aspects of the language network have been compromised, the mechanisms underlying omissions remain largely unknown. In this study, we used a novel eye tracking approach to probe the cognitive mechanisms of omissions in the logopenic and semantic variants of PPA (PPA-L and PPA-S). For each participant, we identified pictures of common objects (e.g., animals, tools) that they could name aloud correctly, as well as pictures that elicited an omission. In a separate word-to-picture matching task, those pictures appeared as targets embedded among an array with 15 foils. Participants were given a verbal cue and tasked with pointing to the target, while eye movements were monitored. On trials with correctly-named targets, controls and both PPA groups ceased visual search soon after foveating the target. On omission trials, however, the PPA-S group failed to stop searching, and went on to view many foils “post-target”. As further indication of impaired word knowledge, gaze of the PPA-S group was subject to excessive “taxonomic capture”, such that they spent less time viewing the target and more time viewing related foils on omission trials. In contrast, viewing behavior of the PPA-L group was similar to controls on both correctly-named and omission trials. These results indicate that the mechanisms of omission in PPA differ by variant. In PPA-S, anterior temporal lobe degeneration causes taxonomic blurring, such that words from the same category can no longer be reliably distinguished. In PPA-L, word knowledge remains relatively intact, and omissions instead appear to be caused by downstream factors (e.g., lexical access, phonological encoding). These findings demonstrate that when words fail, eye movements can be particularly informative. |
Ryan M. O'Leary; Jonathan Neukam; Thomas A. Hansen; Alexander J. Kinney; Nicole Capach; Mario A. Svirsky; Arthur Wingfield In: Trends in Hearing, vol. 27, pp. 1–22, 2023. @article{OLeary2023a,Speech that has been artificially accelerated through time compression produces a notable deficit in recall of the speech content. This is especially so for adults with cochlear implants (CI). At the perceptual level, this deficit may be due to the sharply degraded CI signal, combined with the reduced richness of compressed speech. At the cognitive level, the rapidity of time-compressed speech can deprive the listener of the ordinarily available processing time present when speech is delivered at a normal speech rate. Two experiments are reported. Experiment 1 was conducted with 27 normal-hearing young adults as a proof-of-concept demonstration that restoring lost processing time by inserting silent pauses at linguistically salient points within a time-compressed narrative (“time-restoration”) returns recall accuracy to a level approximating that for a normal speech rate. Noise vocoder conditions with 10 and 6 channels reduced the effectiveness of time-restoration. Pupil dilation indicated that additional effort was expended by participants while attempting to process the time-compressed narratives, with the effortful demand on resources reduced with time restoration. In Experiment 2, 15 adult CI users tested with the same (unvocoded) materials showed a similar pattern of behavioral and pupillary responses, but with the notable exception that meaningful recovery of recall accuracy with time-restoration was limited to a subgroup of CI users identified by better working memory spans, and better word and sentence recognition scores. Results are discussed in terms of sensory-cognitive interactions in data-limited and resource-limited processes among adult users of cochlear implants. |
Julie Ouerfelli-Ethier; Romain Fournet; Aarlenne Z. Khan; Laure Pisella Spatial bias in anti-saccade endpoints following bilateral dorsal posterior parietal lesions Journal Article In: European Journal of Neuroscience, vol. 58, no. 6, pp. 3488–3502, 2023. @article{OuerfelliEthier2023a,Anti-saccades are eye movements in which the saccade is executed in the opposite direction of a visual target and are often hypometric. Because the visual target and saccade goal are decoupled, it has been suggested that competition between the two locations occurs and needs to be resolved. It has been hypothesized that the hypometria of anti-saccades reflects this spatial competition by revealing a bias towards the visual target. To confirm that this hypometria is not simply due to reduced gain, we tested 10 healthy subjects on three different anti-saccade spatial configuration tasks: 90° away across hemifields, 90° away within the same hemifield and 180° away (classic, diagonally opposite). Specifically, we examined whether saccade endpoints showed evidence for the visual target location's interference with anti-saccade programming and execution processes. Among other neural substrates involved in anti-saccades production, the dorsal posterior parietal cortex (PPC) has been implicated in the spatial inhibition of contralateral visual target. To gain insight into the neural processes involved in spatial competition during anti-saccades, we also tested one patient with a bilateral dorsal PPC lesion. In all spatial configurations, we observed that anti-saccade endpoints demonstrated a spatial bias towards the visual target for all participants, likely due to an incomplete inhibition of the visual target location. This spatial bias was exacerbated in our patient, which suggests that the dorsal PPC contributes to the amalgamation of the two competing spatial representations. |
Srishty Aggarwal; Supratim Ray In: Cerebral Cortex Communications, vol. 4, no. 2, pp. 1–12, 2023. @article{Aggarwal2023,The power spectral density (PSD) of the brain signals is characterized by two distinct features: oscillations, which are represented as distinct “bumps,” and broadband aperiodic activity, that reduces in power with increasing frequency and is characterized by the slope of the power falloff. Recent studies have shown a change in the slope of the aperiodic activity with healthy aging and mental disorders. However, these studies analyzed slopes over a limited frequency range (<100 Hz). To test whether the PSD slope is affected over a wider frequency range with aging and mental disorder, we analyzed the slope till 800 Hz in electroencephalogram data recorded from elderly subjects (>49 years) who were healthy (n = 217) or had mild cognitive impairment (MCI; n = 11) or Alzheimer's Disease (AD; n = 5). Although the slope reduced up to ~ 150 Hz with healthy aging (as shown previously), surprisingly, at higher frequencies (>200 Hz), it increased with age. These results were observed in all electrodes, for both eyes open and eyes closed conditions, and for different reference schemes. However, slopes were not significantly different in MCI/AD subjects compared with healthy controls. Overall, our results constrain the biophysical mechanisms that are reflected in the PSD slopes in healthy and pathological aging. |
Francesca Ales; Luciano Giromini; Lara Warmelink; Megan Polden; Thomas Wilcockson; Claire Kelly; Christina Winters; Alessandro Zennaro; Trevor Crawford On the use of eye movements in symptom validity assessment of feigned schizophrenia Journal Article In: Psychological Injury and Law, vol. 16, no. 1, pp. 83–97, 2023. @article{Ales2023a,Assessing the credibility of reported mental health problems is critical in a variety of assessment situations, particularly in forensic contexts. Previous research has examined how the assessment of performance validity can be improved through the use of bio-behavioral measures (e.g., eye movements). To date, however, there is a paucity of literature on the use of eye tracking technology in assessing the validity of presented symptoms of schizophrenia, a disorder that is known to be associated with oculomotor abnormalities. Thus, we collected eye tracking data from 83 healthy individuals during the completion of the Inventory of Problems – 29 and investigated whether the oculomotor behavior of participants instructed to feign schizophrenia would differ from those of control participants asked to respond honestly. Results showed that feigners had a longer dwell time and a greater number of fixations in the feigning-keyed response options, regardless of whether they eventually endorsed those options (d > 0.80). Implications on how eye tracking technology can deepen comprehension on simulation strategies are discussed, as well as the potential of investigating eye movements to advance the field of symptom validity assessment. |
Talia Ariss; Catharine E. Fairbairn; Michael A. Sayette; Brynne A. Velia; Howard Berenbaum; Sarah Brown-Schmidt Where to look? Alcohol, affect, and gaze behavior during a virtual social interaction Journal Article In: Clinical Psychological Science, vol. 11, no. 2, pp. 1–14, 2023. @article{Ariss2023,COVID-19 forced social interactions to move online. Yet researchers have little understanding of the mental-health consequences of this shift. Given pandemic-related surges in emotional disorders and problematic drinking, it becomes imperative to understand the cognitive and affective processes involved in virtual interactions and the impact of alcohol in virtual social spaces. Participants (N = 246) engaged in an online video call while their gaze behavior was tracked. Before the interaction, participants were randomly assigned to receive an alcoholic or control beverage. Participants' affect was repeatedly assessed. Results indicated that a proportionally larger amount of time spent gazing at oneself (vs. one's interaction partner) predicted significantly higher negative affect after the exchange. Furthermore, alcohol independently increased self-directed attention, failing to demonstrate its typically potent social-affective enhancement in this virtual context. Results carry potential implications for understanding factors that increase risk for hazardous drinking and negative affect in an increasingly virtual world. |
Katharine Aveni; Juweiriya Ahmed; Arielle Borovsky; Ken McRae; Mary E. Jenkins; Katherine Sprengel; J. Alexander Fraser; Joseph B. Orange; Thea Knowles; Angela C. Roberts Predictive language comprehension in Parkinson's disease Journal Article In: PLoS ONE, vol. 18, pp. 1–32, 2023. @article{Aveni2023,Verb and action knowledge deficits are reported in persons with Parkinson's disease (PD), even in the absence of dementia or mild cognitive impairment. However, the impact of these deficits on combinatorial semantic processing is less well understood. Following on previous verb and action knowledge findings, we tested the hypothesis that PD impairs the ability to integrate event-based thematic fit information during online sentence processing. Specifically, we anticipated persons with PD with age-typical cognitive abilities would perform more poorly than healthy controls during a visual world paradigm task requiring participants to predict a target object constrained by the thematic fit of the agent-verb combination. Twenty-four PD and 24 healthy age-matched participants completed comprehensive neuropsychological assessments. We recorded participants' eye movements as they heard predictive sentences (The fisherman rocks the boat) alongside target, agent-related, verb-related, and unrelated images. We tested effects of group (PD/control) on gaze using growth curve models. There were no significant differences between PD and control participants, suggesting that PD participants successfully and rapidly use combinatory thematic fit information to predict upcoming language. Baseline sentences with no predictive information (e.g., Look at the drum) confirmed that groups showed equivalent sentence processing and eye movement patterns. Additionally, we conducted an exploratory analysis contrasting PD and controls' performance on low-motion-content versus high-motion-content verbs. This analysis revealed fewer predictive fixations in high-motion sentences only for healthy older adults. PD participants may adapt to their disease by relying on spared, non-action-simulation-based language processing mechanisms, although this conclusion is speculative, as the analyses of high- vs. low-motion items was highly limited by the study design. These findings provide novel evidence that individuals with PD match healthy adults in their ability to use verb meaning to predict upcoming nouns despite previous findings of verb semantic impairment in PD across a variety of tasks. |
Thomas R. Barber; Kinan Muhammed; Daniel Drew; Kevin M. Bradley; Daniel R. McGowan; Johannes C. Klein; Sanjay G. Manohar; Michele T. M. Hu; Masud Husain Reward insensitivity is associated with dopaminergic deficit in rapid eye movement sleep behaviour disorder Journal Article In: Brain, vol. 146, no. 6, pp. 2502–2511, 2023. @article{Barber2023,Idiopathic rapid eye movement sleep behaviour disorder (iRBD) has now been established as an important marker of the prodromal stage of Parkinson's disease and related synucleinopathies. However, although dopamine transporter single photon emission computed tomography (SPECT) has been used to demonstrate the presence of nigro-striatal deficit in iRBD, quantifiable correlates of this are currently lacking. Sensitivity to rewarding stimuli is reduced in some people with Parkinson's disease, potentially contributing to aspects of the neuropsychiatric phenotype in these individuals. Furthermore, a role for dopaminergic degeneration is suggested by the fact that reward insensitivity can be improved by dopaminergic medications. Patients with iRBD present a unique opportunity to study the relationship between reward sensitivity and early dopaminergic deficit in the unmedicated state. Here, we investigate whether a non-invasive, objective measure of reward sensitivity might be a marker of dopaminergic status in prodromal Parkinson's disease by comparing with SPECT/CT measurement of dopaminergic loss in the basal ganglia. Striatal dopaminergic deficits in iRBD are associated with progression to Parkinsonian disorders. Therefore, identification of a clinically measurable correlate of this degenerative process might provide a basis for the development of novel risk stratification tools. Using a recently developed incentivized eye-tracking task, we quantified reward sensitivity in a cohort of 41 patients with iRBD and compared this with data from 40 patients with Parkinson's disease and 41 healthy controls. Patients with iRBD also underwent neuroimaging with dopamine transporter SPECT/CT. Overall, reward sensitivity, indexed by pupillary response to monetary incentives, was reduced in iRBD cases compared with controls and was not significantly different to that in patients with Parkinson's disease. However, in iRBD patients with normal dopamine transporter SPECT/CT imaging, reward sensitivity was not significantly different from healthy controls. Across all iRBD cases, a positive association was observed between reward sensitivity and dopaminergic SPECT/CT signal in the putamen. These findings demonstrate a direct relationship between dopaminergic deficit and reward sensitivity in patients with iRBD and suggest that measurement of pupillary responses could be of value in models of risk stratification and disease progression in these individuals. |
Dana Basel; Amit Lazarov A sight for sore eyes? Attention allocation to obsession-provoking stimuli and stimuli reflecting compulsion completion Journal Article In: Motivation and Emotion, pp. 1–15, 2023. @article{Basel2023,Research on attention allocation in OCD has exclusively used obsession-provoking threat stimuli, showing sustained attention over neutral ones. Recently, however, a study contrasting neutral stimuli with stimuli depicting the completion of compulsive acts (end-states stimuli), which is associated with a reduced anxiety (negative reinforcement), showed similar results. Yet, as relative to neutral stimuli end-state stimuli were also OCD-related, these results may still reflect obsession-related distress rather than relief brought on by stimuli signaling compulsion completion. Also, end-states stimuli were not systematically validated. In Study 1, participants rated the subjective discomfort experienced when viewing traditional obsession-provoking threat pictures and novel end-states pictures. We first compared participants with high (HOC) and low (LOC) levels of obsessive-compulsive symptoms, and then clinically diagnosed OCD participants and matched healthy controls. In study 2, we compared gaze patterns of HOC and LOC participants while freely viewing 2-by-2 matrices directly contrasting two threat and two end-state stimuli. Study 1 showed a larger difference in experienced discomfort when viewing the end-state stimuli, compared to threat stimuli, for both OC groups compared with their respected control groups. Study 2 showed that while LOC participants demonstrated no difference in dwell time on threat vs. end-state pictures, the HOC group allocated more attention toward the latter. Both groups were more prone to fixate first the threat pictures. Task reliability was high. Attention allocation in OCD may also be affected by cues signaling the completion of compulsive acts. |
Dana Basel; Moriah Magen; Amit Lazarov Increased attention allocation to stimuli reflecting end-states of compulsive behaviors among obsessive compulsive individuals Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 14–18, 2023. @article{Basel2023a,Attentional research in OCD has focused solely on threat stimuli, assumed to provoke related obsessions and ensuing compulsions. OCD-related stimuli depicting the completion of compulsive acts (“end-states”) have yet to be examined. Past research also neglected to explore the reliability of tasks used. Here, attention allocation to both stimuli types was examined. Participants with high (HOC) and low (LOC) levels of obsessive–compulsive symptoms freely viewed three blocks of 30 two-by-two picture matrices, each including two OCD-related (cleaning$backslash$checking$backslash$ordering) and two neutral pictures, presented for eight seconds, while their gaze was recorded. Participants completed two task versions – one with traditional threat stimuli and one with novel stimuli signaling compulsions end-states. Only the end-state version yielded significant results, showing that HOC participants, compared to LOC participants, spent significantly more time fixating on OCD-related stimuli. Results remained significant after controlling for anxiety, stress, and depression. Task reliability was high. OCD-related stimuli signaling end-states of compulsive behavior should be incorporated in attentional research in OCD. |
Judith Bek; Emma Gowen; Stefan Vogt; Trevor J. Crawford; Ellen Poliakoff Observation and imitation of object-directed hand movements in Parkinson's disease Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 1–9, 2023. @article{Bek2023,Action observation and imitation may facilitate movement in Parkinson's disease (PD). People with PD have been found to imitate intransitive actions similarly to neurologically healthy older adults, but their imitation of object-directed hand movements has not previously been investigated using kinematic measures. The present study examined observation and imitation of object-directed hand movements in 18 participants with PD and 21 neurologically healthy age-matched control participants. Participants observed and immediately imitated sequences showing a human hand reaching for and transferring an object between horizontal positions. Both groups significantly modulated their finger movements, showing higher vertical amplitude when imitating elevated compared to direct trajectories. In addition, movements were lower in vertical amplitude and higher in velocity when imitating the reaching segment than the transfer segment. Eye-tracking revealed that controls made smaller saccades when observing predictable than unpredictable elevated movements, but no effects of predictability on eye movements were found for the PD group. This study provides quantitative evidence that people with mild to moderate PD can imitate object-directed hand movement kinematics, although their prediction of such movements may be reduced. These findings suggest that interventions targeting object-directed actions may capitalize on the ability of people with PD to imitate kinematic parameters of a demonstrated movement. |
Alessio Bellato; Iti Arora; Puja Kochhar; Danielle Ropar; Chris Hollis; Madeleine J. Groom Relationship between autonomic arousal and attention orienting in children and adolescents with ADHD, autism and co-occurring ADHD and autism Journal Article In: Cortex, vol. 166, pp. 306–321, 2023. @article{Bellato2023,Introduction: Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) may be characterized by different profiles of visual attention orienting. However, there are also many inconsistent findings emerging from the literature, probably due to the fact that the potential effect of autonomic arousal (which has been proposed to be dysregulated in these conditions) on oculomotor performance has not been investigated before. Moreover, it is not known how visual attention orienting is affected by the co-occurrence of ADHD and autism in people with a double diagnosis. Methods: 99 children/adolescents with or without ADHD and/or autism (age 10.79 ± 2.05 years, 65% boys) completed an adapted version of the gap-overlap task (with baseline and overlap trials only). The social salience and modality of stimuli were manipulated between trials. Eye movements and pupil size were recorded. We compared saccadic reaction times (SRTs) between diagnostic groups and investigated if a trial-by-trial association existed between pre-saccadic pupil size and SRTs. Results: Faster orienting (shorter SRT) was found for baseline compared to overlap trials, faces compared to non-face stimuli and–more evidently in children without ADHD and/or autism–for multi-modal compared to uni-modal stimuli. We also found a linear negative association between pre-saccadic pupil size and SRTs, in autistic participants (without ADHD), and a quadratic association in children with ADHD (without autism), for which SRTs were slower when intra-individual pre-saccadic pupil size was smallest or largest. Conclusion: Our findings are in line with previous literature and indicate a possible effect of dysregulated autonomic arousal on oculomotor mechanisms in autism and ADHD, which should be further investigated in future research studies with larger samples, to reliably investigate possible differences between children with single and dual diagnoses. |
Laura Convertino; Daniel Bush; Fanfan Zheng; Rick A. Adams; Neil Burgess Reduced grid-like theta modulation in schizophrenia Journal Article In: Brain, vol. 146, no. 5, pp. 2191–2198, 2023. @article{Convertino2023,The hippocampal formation has been implicated in the pathophysiology of schizophrenia, with patients showing impairments in spatial and relational cognition, structural changes in entorhinal cortex and reduced theta coherence with medial prefrontal cortex. Both the entorhinal cortex and medial prefrontal cortex exhibit a 6-fold (or ‘hexadirectional') modulation of neural activity during virtual navigation that is indicative of grid cell populations and associated with accurate spatial navigation. Here, we examined whether these grid-like patterns are disrupted in schizophrenia. We asked 17 participants with diagnoses of schizophrenia and 23 controls (matched for age, sex and IQ) to perform a virtual reality spatial navigation task during magnetoencephalography. The control group showed stronger 4–10 Hz theta power during movement onset, as well as hexadirectional modulation of theta band oscillatory activity in the right entorhinal cortex whose directional stability across trials correlated with navigational accuracy. This hexadirectional modulation was absent in schizophrenia patients, with a significant difference between groups. These results suggest that impairments in spatial and relational cognition associated with schizophrenia may arise from disrupted grid firing patterns in entorhinal cortex. |
Frances G Cooley; David Quinto-pozos Supplemental material for examining speech-based phonological recoding during reading for adolescent deaf signers Journal Article In: Journal of Experimental Psychology: General, vol. 152, no. 7, pp. 1995–2007, 2023. @article{Cooley2023,Much of the debate regarding literacy development in deaf and hard-of-hearing readers surrounds whether there is dependence on phonological decoding of print to speech for such readers, and the literature is mixed. While some reports of deaf children and adults demonstrate the influence of speech-based processing during reading, others find little to no evidence of speech-sound activation. In order to examine the role of speech- based phonological codes when reading, we utilized eye-tracking to examine eye-gaze behaviors employed by deaf children and a control group of hearing primary-school children when encountering target words in sentences. The target words were of three types: correct, homophonic errors, and nonhomophonic errors.We examined eye-gaze fixations when first encountering target words and, if applicable, when rereading those words. The results revealed that deaf and hearing readers differed in their eye-movement behaviors when re- reading the words, but they did not demonstrate differences for first encounters with the words. Hearing read- ers treated homophonic and nonhomophonic error words differently during their second encounter with the target while deaf readers did not, suggesting that deaf signers did not engage in phonological decoding to the same degree as hearing readers did. Further, deaf signers performed fewer overall regressions to target words than hearing readers, suggesting that they depended less on regressions to resolve errors in the text. |
Chloe Cooper; Andrew Isaac Meso Cognitive-perceptual traits associated with autism and schizotypy influence use of physics during predictive visual tracking Journal Article In: European Journal of Neuroscience, vol. 58, no. 10, pp. 4236–4254, 2023. @article{Cooper2023,Schizophrenia and autism spectrum disorder (ASD) can disrupt cognition and consequently behaviour. Traits of ASD and the subclinical manifestation of schizophrenia called schizotypy have been studied in healthy populations with overlap found in trait profiles linking ASD social deficits to negative schizotypy and ASD attention to detail to positive schizotypy. Here, we probed the relationship between subtrait profiles, cognition and behaviour, using a predictive tracking task to measure individuals' eye movements under three gravity conditions. A total of 48 healthy participants tracked an on-screen projected ball under familiar gravity, inverted upward acceleration (against gravity) and horizontal gravity control conditions while eye movements were recorded and dynamic performance quantified. Participants completed ASD and schizotypy inventories generating highly correlated scores |
Bing Dai; Kwang Meng Cham; Larry Allen Abel Visual search in infantile nystagmus syndrome Journal Article In: Clinical and Experimental Optometry, pp. 1–8, 2023. @article{Dai2023,Clinical relevance: Research on infantile nystagmus syndrome (INS) and visual search is limited. Conducting this research could assist practitioners in understanding how INS affects the real-life visual activities of patients and aid in developing new clinical visual function assessments for INS. Background: The aim of this work is to investigate how subjects with INS perform visual search tasks, and, particularly, to assess how INS subjects perform when targets are located at their null position or away from it, and when under additional cognitive demands. Methods: INS subjects (N = 15) and controls (N = 20) performed conjunction and feature search tasks, both with and without mental arithmetic. Search performance was assessed using log-transformed total search time, gaze-dependent search time, and accuracy. Cognitive demand was quantified by pupil size and the NASA task-load index score. Results: INS subjects showed longer search times compared to controls in conjunction search (P < 0.01), but not in feature search. Within INS and control subjects, the total search times were significantly increased by the addition of mental arithmetic (P < 0.0001). There was no difference in gaze-dependent search times between null target position and 15° away from null target position of subjects in conjunction search (P > 0.05). Accuracies were 100% for both control and INS subjects in both conjunction and feature search. Conclusion: Conjunction visual search was impaired in adult INS subjects, and further worsened under increased cognitive demand. The null position did not affect the visual search performance in INS. |
Leonhard H. Drescher; C. Nico Boehler; Jan R. Wiersema A pupillometric investigation of state regulation in adults scoring high versus low on ADHD symptomatology Journal Article In: Acta Psychologica, vol. 235, pp. 1–10, 2023. @article{Drescher2023,According to the state regulation deficit (SRD) account, ADHD is associated with difficulties regulating tonic arousal levels, which may be due to inefficient effort allocation. We aimed to test the SRD account by using a target detection task with three different event rates (ER; 700 ms, 1800 ms, 6000 ms), in order to manipulate the tonic arousal state and its effects on performance and pupil indices in adults with high (n = 40) versus low (n = 36) ADHD symptom levels. In an additional condition, a fast ER (700 ms) was accompanied by auditory white noise (WN), to further increase tonic arousal level. The ER manipulation had a clear effect on RT and variability of RT. These effects were more pronounced for the high-ADHD group, especially for variability of RT with decreasing ER, suggestive of deficient upregulation of a tonic arousal state in that group, in line with their self-reported SRDs in daily life. Adding WN to the fast condition led to more errors, however similarly for both groups. Contrary to our predictions, the ER manipulation had no effect on tonic pupil size (as a measure of tonic arousal). Phasic pupil amplitude (as a measure of cognitive effort) linearly increased with decreasing ER, suggesting more effort allocation during slower ERs. WN decreased phasic pupil amplitude, but had no impact on tonic pupil size. Importantly, however, no ADHD-related differences were present for the pupil indices. In conclusion, adults with elevated levels of ADHD symptoms reported more SRDs in daily life and showed a performance pattern that suggests difficulties in upregulating but not downregulating the tonic arousal state. Surprisingly, these findings were not accompanied by group differences in pupillometric indices. This casts some doubts on the relationship between these measures of autonomic nervous system activity and state regulation, in particular in the context of ADHD symptomatology. |
Kacie Dunham-Carr; Jacob I. Feldman; David M. Simon; Sarah R. Edmunds; Alexander Tu; Wayne Kuang; Julie G. Conrad; Pooja Santapuram; Mark T. Wallace; Tiffany G. Woynaroski The processing of audiovisual speech is linked with vocabulary in autistic and monautistic children: An ERP study Journal Article In: Brain Sciences, vol. 13, no. 7, pp. 1–15, 2023. @article{DunhamCarr2023,Explaining individual differences in vocabulary in autism is critical, as understanding and using words to communicate are key predictors of long-term outcomes for autistic individuals. Differences in audiovisual speech processing may explain variability in vocabulary in autism. The efficiency of audiovisual speech processing can be indexed via amplitude suppression, wherein the amplitude of the event-related potential (ERP) is reduced at the P2 component in response to audiovisual speech compared to auditory-only speech. This study used electroencephalography (EEG) to measure P2 amplitudes in response to auditory-only and audiovisual speech and norm-referenced, standardized assessments to measure vocabulary in 25 autistic and 25 nonautistic children to determine whether amplitude suppression (a) differs or (b) explains variability in vocabulary in autistic and nonautistic children. A series of regression analyses evaluated associations between amplitude suppression and vocabulary scores. Both groups demonstrated P2 amplitude suppression, on average, in response to audiovisual speech relative to auditory-only speech. Between-group differences in mean amplitude suppression were nonsignificant. Individual differences in amplitude suppression were positively associated with expressive vocabulary through receptive vocabulary, as evidenced by a significant indirect effect observed across groups. The results suggest that efficiency of audiovisual speech processing may explain variance in vocabulary in autism. |
Apolline Durtette; Franca Schmid; Sarah Barrière; Alexandre Obert; Julie Lang; Delphine Raucher-Chéné; Fabien Gierski; Arthur Kaladjian; Audrey Henry Facial emotion recognition processes according to schizotypal personality traits: An eye-tracking study Journal Article In: International Journal of Psychophysiology, vol. 190, pp. 60–68, 2023. @article{Durtette2023,Facial emotion recognition has been shown to be impaired among patients with schizophrenia and, to a lesser extent, among individuals with high levels of schizotypal personality traits. However, aspects of gaze behavior during facial emotion recognition among the latter are still unclear. This study therefore investigated the relations between eye movements and facial emotion recognition among nonclinical individuals with schizotypal personality traits. A total of 83 nonclinical participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a facial emotion recognition task. Their gaze behavior was recorded by an eye-tracker. Self-report questionnaires measuring anxiety, depressive symptoms, and alexithymia were administered. At the behavioral level, correlation analyses showed that higher SPQ scores were associated with lower surprise recognition accuracy scores. Eye-tracking data revealed that higher SPQ scores were associated with shorter dwell time on relevant facial features during sadness recognition. Regression analyses revealed that the total SPQ score was the only significant predictor of eye movements during sadness recognition, and depressive symptoms were the only significant predictor of surprise recognition accuracy. Furthermore, dwell time predicted response times for sadness recognition in that shorter dwell time on relevant facial features was associated with longer response times. Schizotypal traits may be associated with decreased attentional engagement in relevant facial features during sadness recognition and impede participants' response times. Slower processing and altered gaze patterns during the processing of sad faces could lead to difficulties in everyday social situations in which information must be rapidly processed to enable the successful interpretation of other people's behavior. |
Ciara Egan; Joshua S. Payne; Manon W. Jones In: Neuropsychologia, vol. 184, pp. 1–8, 2023. @article{Egan2023,Readers with developmental dyslexia are known to be impaired in representing and accessing phonology, but their ability to process meaning is generally considered to be intact. However, neurocognitive studies show evidence of a subtle semantic processing deficit in dyslexic readers, relative to their typically-developing peers. Here, we compared dyslexic and typical adult readers on their ability to judge semantic congruency (congruent vs. inconcongruent) in short, two-word phrases, which were further manipulated for phonological relatedness (alliterating vs. non-alliterating); “dazzling-diamond”; “sparkling-diamond”; “dangerous-diamond”; and “creepy-diamond”. At the level of behavioural judgement, all readers were less accurate when evaluating incongruent alliterating items compared with incongruent non-aliterating, suggesting that phonological patterning creates the illusion of semantic congruency (as per Egan et al., 2020). Dyslexic readers showed a similar propensity for this form-meaning relationship despite a phonological processing impairment as evidenced in the cognitive and literacy indicative assessments. Dyslexic readers also showed an overall reduction in the ability to accurately judge semantic congruency, suggestive of a subtle semantic impairment. Whilst no group differences emerged in the electrophysiological measures, our pupil dilation measurements revealed a global tendency for dyslexic readers to manifest a reduced attentional response to these word stimuli, compared with typical readers. Our results show a broad manifestation of neurocognitive differences in adult dyslexic and typical readers' processing of print, at the level of autonomic arousal as well as in higher level semantic judgements. |
Ciara Egan; Anna Siyanova-Chanturia; Paul Warren; Manon W. Jones As clear as glass: How figurativeness and familiarity impact simile processing in readers with and without dyslexia Journal Article In: Quarterly Journal of Experimental Psychology, vol. 76, no. 2, pp. 231–247, 2023. @article{Egan2023a,For skilled readers, idiomatic language confers faster access to overall meaning compared with non-idiomatic language, with a processing advantage for figurative over literal interpretation. However, currently very little research exists to elucidate whether atypical readers—such as those with developmental dyslexia—show such a processing advantage for figurative interpretations of idioms, or whether their reading impairment implicates subtle differences in semantic access. We wanted to know whether an initial figurative interpretation of similes, for both typical and dyslexic readers, is dependent on familiarity. Here, we tracked typical and dyslexic readers' eye movements as they read sentences containing similes (e.g., as cold as ice), orthogonally manipulated for novelty (e.g., familiar: as cold as ice, novel: as cold as snow) and figurativeness (e.g., literal: as cold as ice [low temperature], figurative: as cold as ice [emotionally distant]), with figurativeness being defined by the sentence context. Both participant groups exhibited a processing advantage for familiar and figurative similes over novel and literal similes. However, compared with typical readers, participants with dyslexia had greater difficulty processing similes both when they were unfamiliar and when the context biased the simile meaning towards a literal rather than a figurative interpretation. Our findings suggest a semantic processing anomaly in dyslexic readers, which we discuss in light of recent literature on sentence-level semantic processing. |
Michelle L. Eisenberg; Thomas L. Rodebaugh; Shaney Flores; Jeffrey M. Zacks Impaired prediction of ongoing events in posttraumatic stress disorder Journal Article In: Neuropsychologia, vol. 188, pp. 1–12, 2023. @article{Eisenberg2023,The ability to make accurate predictions about what is going to happen in the near future is critical for comprehension of everyday activity. However, predictive processing may be disrupted in Posttraumatic Stress Disorder (PTSD). Hypervigilance may lead people with PTSD to make inaccurate predictions about the likelihood of future danger. This disruption in predictive processing may occur not only in response to threatening stimuli, but also during processing of neutral stimuli. Therefore, the current study investigated whether PTSD was associated with difficulty making predictions about near-future neutral activity. Sixty-three participants with PTSD and 63 trauma controls completed two tasks, one testing explicit prediction and the other testing implicit prediction. Higher PTSD severity was associated with greater difficulty with predictive processing on both of these tasks. These results suggest that effective treatments to improve functional outcomes for people with PTSD may work, in part, by improving predictive processing. |
Elizabeth A. Enright; Stephanie M. Eick; Rachel Morello-Frosch; Andréa Aguiar; Megan L. Woodbury; Jenna L. N. Sprowles; Sarah Dee Geiger; Jessica Trowbridge; Aileen Andrade; Sabrina Smith; June-Soo Park; Erin DeMicco; Amy M. Padula; Tracey J. Woodruff; Susan L. Schantz In: Neurotoxicology and Teratology, vol. 98, pp. 1–10, 2023. @article{Enright2023,Background: Prenatal exposure to per- and polyfluoroalkyl substances (PFAS) has been linked to a wide array of adverse maternal and child health outcomes. However, studies examining PFAS in relation to offspring cognition have been inconclusive. Objective: We examined whether prenatal exposure to a mixture of PFAS was related to cognition in 7.5-month-old infants. Methods: Our analytic sample included participants enrolled in the Chemicals in Our Bodies (CIOB) and Illinois Kids Development Study (IKIDS) cohorts (N = 163). Seven PFAS were measured in 2nd trimester maternal serum samples and were detected in >65% of participants. Infant cognition was measured with a visual recognition memory task using an infrared eye tracker when infants were 7.5 months old. This task included familiarization trials where each infant was shown two identical faces and test trials where each infant was shown the familiar face paired with a novel face. In familiarization, we assessed average run duration (time looking at familiarization stimuli before looking away) as a measure of information processing speed, in addition to time to familiarization (time to reach 20 s of looking at stimuli) and shift rate (the number of times infants looked between stimuli), both as measures of attention. In test trials, we assessed novelty preference (proportion of time looking to the novel face) to measure recognition memory. Linear regression was used to estimate associations of individual PFAS with cognitive outcomes, while Bayesian kernel machine regression (BKMR) was used to estimate mixture effects. Results: In adjusted single-PFAS linear regression models, an interquartile range increase in PFNA, PFOA, PFOS, PFHxS, PFDeA, and PFUdA was associated with an increase in shift rate, reflecting better visual attention. Using BKMR, increasing quartiles of the PFAS mixture was similarly associated with a modest increase in shift rate. There were no significant associations between PFAS exposure and time to reach familiarization (another measure of attention), average run duration (information processing speed), or novelty preference (visual recognition memory). Conclusion: In our study population, prenatal PFAS exposure was modestly associated with an increase in shift rate and was not strongly associated with any adverse cognitive outcomes in 7.5-month-old infants. |
Hatice Eraslan Boz; Koray Koçoğlu; Müge Akkoyun; Işıl Yağmur Tüfekci; Merve Ekin; Gülden Akdal Visual search in Alzheimer's disease and amnestic mild cognitive impairment: An eye-tracking study Journal Article In: Alzheimer's & Dementia Dementia, pp. 1–10, 2023. @article{EraslanBoz2023a,INTRODUCTION: Visual search impairment is a potential cognitive marker for Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI). The aim of this study is to compare eye movements during visual tracking in AD and aMCI patients versus healthy controls (HCs). METHODS: A prospective cohort study included 32 AD and 37 aMCI patients, and 33 HCs. Each participant was asked to look at the target object in a visual stimulus containing one target and eight distractors, and eye movements were recorded with EyeLink 1000 Plus. RESULTS: AD patients had fewer fixations and shorter target fixation duration than aMCI patients and HCs. Fixation durations were also shorter in aMCI patients compared to HCs. Also, AD patients were more fixated on distractors than HCs. DISCUSSION: Our findings revealed that visual search is impaired in the early stages of AD and even aMCI, highlighting the importance of addressing visual processes in the Alzheimer's continuum. Highlights: AD patients looked to distractors more and longer than the target compared to aMCI patients and older healthy individuals. aMCI patients had an impaired visual search pattern compared to healthy controls, just like patients with AD. The visual search task differentiated AD and aMCI patients from healthy individuals without dementia. |
Hatice Eraslan Boz; Koray Koçoğlu; Müge Akkoyun; Işıl Yağmur Tüfekci; Merve Ekin; Gülden Akdal In: Brain and Behavior, vol. 13, no. 11, pp. 1–11, 2023. @article{EraslanBoz2023,Background: Alzheimer's disease (AD) neuropathology affects the brain regions responsible for visuospatial skills. Accumulating evidence points to visual difficulties involving face processing in AD and amnestic mild cognitive impairment (aMCI). No study has so far examined eye movement patterns when viewing faces with neutral expressions in patients with AD. Aim: The objective of this study aimed to examine the eye movements of patients with early-stage AD, aMCI, and healthy controls (HC) during viewing face images. Materials&Methods: Thirty-one AD, 37 aMCI, and 33 HC were included in the study. Eye movements in facial stimuli were recorded with the EyeLink 1000 Plus eye-tracker. Results: Our findings showed that AD patients looked less at the eye area of interest than the nose and mouth areas of interest compared to aMCI and HC. Regardless of the group, all participants looked at the eye and nose areas of interest more and longer in the mouth area of interest. In addition, the first fixation duration to the eye area of interest of all participants was shorter than that of the nose and mouth. Discussion: Consistent with our study, studies in healthy adults revealed eye movement patterns that focused more on the eyes and nose. AD patients are unable to pay attention to the salient parts of faces, tending to focus instead on the non-informative parts. Conclusion: Our study is the first to reveal eye movement differences in face processing in AD. |
Hatice Eraslan Boz; Koray Koçoğlu; Müge Akkoyun; Işıl Yağmur Tüfekci; Merve Ekin; Pınar Özçelik; Gülden Akdal Examination of eye movements during visual scanning of real-world images in Alzheimer's disease and amnestic mild cognitive impairment Journal Article In: International Journal of Psychophysiology, vol. 190, pp. 84–93, 2023. @article{EraslanBoz2023c,Available evidence shows that Alzheimer's disease (AD) patients display inefficiencies in visual scanning of their surroundings, directing their attention towards non-relevant aspects of scenes. Not much is known about eye movements during visual scanning in individuals with amnestic mild cognitive impairment (aMCI). Notably, a consensus has yet to be reached on this issue. Furthermore, prior research has indicated the existence of visual attention deficits in individuals diagnosed with AD and aMCI. The objective of this study was to examine the visual scanning patterns of individuals diagnosed with AD, aMCI, and healthy controls (HC) when viewing various scenes. Thirty patients with AD, 32 aMCI, and 32 HC were included in the study. A set of 30 real-life scene images were presented to the participants in the visual scanning task. Participants' eye events were monitored using the EyeLink 1000 Plus in this task. The results indicate a significant reduction in total fixation duration, number of scanned areas, fixation counts, and saccade counts in AD as compared to those with aMCI and HC. The research did not reveal any significant statistical differences in eye parameters between the aMCI and HC groups. This study found abnormalities in visual scanning in AD compared to aMCI and HC. Visual scanning patterns of aMCI patients were not different from HC. Previous studies have specifically shown visual attention difficulties in AD and MCI. Our findings may be related to visual attention difficulties in AD. In addition, this study is the first to examine visual scanning behaviour with real-world images in AD and aMCI. |
Lisa Feldmann; Carolin Zsigo; Isabelle Mörtl; Jürgen Bartling; Christian Wachinger; Frans Oort; Gerd Schulte-Körne; Ellen Greimel Emotion regulation in adolescents with major depression – Evidence from a combined EEG and eye-tracking study Journal Article In: Journal of Affective Disorders, vol. 340, pp. 899–906, 2023. @article{Feldmann2023,Background: Adolescent major depression (MD) is characterized by deficits in emotion regulation (ER). Little is known about the neurophysiological correlates that are associated with these deficits. Moreover, the additional examination of visual attention during ER would allow a more in-depth understanding of ER deficits but has not yet been applied simultaneously. Methods: N = 33 adolescents with MD and n = 35 healthy controls (HCs) aged 12–18 years performed an ER task during which they either a) down-regulated their negative affective response to negative images via cognitive reappraisal or b) attended the images without changing their affective response. During the task, the Late Positive Potential (LPP), gaze fixations on emotional image aspects, and self-reported affective responses were collected simultaneously. Results: Compared to HCs, adolescents with MD demonstrated reduced ER success based on self-report but did not differ in LPP amplitudes. Participants in both groups showed increased amplitudes in the middle LPP window when they reappraised negative pictures compared to when they attended them. Only in the HC group, increased LPP amplitudes during reappraisal were paralleled by more positive affective responses. Limitation: The applied stimuli were part of picture databases and might therefore have limited self-relevance. Conclusions: Increased LPP amplitude during ER in both groups might be specific to adolescence and might suggest that ER at this age is challenging and requires a high amount of cognitive resources. These findings provide an important starting point for future interventional studies in youth MD. |
Julia Fietz; Dorothee Pöhlchen; Elisabeth B. Binder; Angelika Erhardt; Susanne Lucae; Norma C. Grandi; Tamara Namendorf; Immanuel Elbau; Laura Leuchs; Leonhard Schilbach; Sanja Ilić-Ćoćić; Julius Ziebula; Iven-Alex Mücke-Heim; Yeho Kim; Julius Pape; Tanja M. Brückl; Anna-Katharine Brem; Frank Padberg; Michael Czisch; Philipp G. Sämann; Victor I. Spoormaker In: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, no. 24, pp. 1–8, 2023. @article{Fietz2023,Background Neurocognitive functioning is a relevant transdiagnostic dimension in psychiatry. As pupil size dynamics track cognitive load during a working memory task, we aimed to explore if this parameter allows identification of psychophysiological subtypes in healthy participants and patients with affective and anxiety disorders. Methods Our sample consisted of 226 participants who completed the n-back task during simultaneous functional magnetic resonance imaging and pupillometry measurements. We used latent class growth modeling to identify clusters based on pupil size in response to cognitive load. In a second step, these clusters were compared on affective and anxiety symptom levels, performance in neurocognitive tests, and functional magnetic resonance imaging activity. Results The clustering analysis resulted in two distinct pupil response profiles: one with a stepwise increasing pupil size with increasing cognitive load (reactive group) and one with a constant pupil size across conditions (nonreactive group). A larger increase in pupil size was significantly associated with better performance in neurocognitive tests in executive functioning and sustained attention. Statistical maps of parametric modulation of pupil size during the n-back task showed the frontoparietal network in the positive contrast and the default mode network in the negative contrast. The pupil response profile of the reactive group was associated with more thalamic activity, likely reflecting better arousal upregulation and less deactivation of the limbic system. Conclusions Pupil measurements have the potential to serve as a highly sensitive psychophysiological readout for detection of neurocognitive deficits in the core domain of executive functioning, adding to the development of valid transdiagnostic constructs in psychiatry. |
JeongJun Park; Seolmin Kim; Hyung Goo R. Kim; Joonyeol Lee Prior expectation enhances sensorimotor behavior by modulating population tuning and subspace activity in sensory cortex Journal Article In: Science Advances, vol. 9, no. 27, pp. 1–20, 2023. @article{Park2023,Prior knowledge facilitates our perception and goal-directed behaviors, particularly when sensory input is lacking or noisy. However, the neural mechanisms underlying the improvement in sensorimotor behavior by prior expectations remain unknown. In this study, we examine the neural activity in the middle temporal (MT) area of visual cortex while monkeys perform a smooth pursuit eye movement task with prior expectation of the visual target's motion direction. Prior expectations discriminately reduce the MT neural responses depending on their preferred directions, when the sensory evidence is weak. This response reduction effectively sharpens neural population direction tuning. Simulations with a realistic MT population demonstrate that sharpening the tuning can explain the biases and variabilities in smooth pursuit, suggesting that neural computations in the sensory area alone can underpin the integration of prior knowledge and sensory evidence. State-space analysis further supports this by revealing neural signals of prior expectations in the MT population activity that correlate with behavioral changes. |
Soon Young Park; Kenneth Holmqvist; Diederick C. Niehorster; Ludwig Huber; Zsófia Virányi How to improve data quality in dog eye tracking Journal Article In: Behavior Research Methods, vol. 55, no. 4, pp. 1513–1536, 2023. @article{Park2023a,Pupil–corneal reflection (P–CR) eye tracking has gained a prominent role in studying dog visual cognition, despite methodological challenges that often lead to lower-quality data than when recording from humans. In the current study, we investigated if and how the morphology of dogs might interfere with tracking of P–CR systems, and to what extent such interference, possibly in combination with dog-unique eye-movement characteristics, may undermine data quality and affect eye-movement classification when processed through algorithms. For this aim, we have conducted an eye-tracking experiment with dogs and humans, and investigated incidences of tracking interference, compared how they blinked, and examined how differential quality of dog and human data affected the detection and classification of eye-movement events. Our results show that the morphology of dogs' face and eye can interfere with tracking methods of the systems, and dogs blink less often but their blinks are longer. Importantly, the lower quality of dog data lead to larger differences in how two different event detection algorithms classified fixations, indicating that the results of key dependent variables are more susceptible to choice of algorithm in dog than human data. Further, two measures of the Nyström & Holmqvist (Behavior Research Methods, 42(4), 188–204, 2010) algorithm showed that dog fixations are less stable and dog data have more trials with extreme levels of noise. Our findings call for analyses better adjusted to the characteristics of dog eye-tracking data, and our recommendations help future dog eye-tracking studies acquire quality data to enable robust comparisons of visual cognition between dogs and humans. |
Christina U. Pfeuffer; Andrea Kiesel; Lynn Huestegge Similar proactive effect monitoring in free and forced choice action modes Journal Article In: Psychological Research, vol. 87, no. 1, pp. 226–241, 2023. @article{Pfeuffer2023,When our actions yield predictable consequences in the environment, our eyes often already saccade towards the locations we expect these consequences to appear at. Such spontaneous anticipatory saccades occur based on bi-directional associations between action and effect formed by prior experience. That is, our eye movements are guided by expectations derived from prior learning history. Anticipatory saccades presumably reflect a proactive effect monitoring process that prepares a later comparison of expected and actual effect. Here, we examined whether anticipatory saccades emerged under forced choice conditions when only actions but not target stimuli were predictive of future effects and whether action mode (forced choice vs. free choice, i.e., stimulus-based vs. stimulus-independent choice) affected proactive effect monitoring. Participants produced predictable visual effects on the left/right side via forced choice and free choice left/right key presses. Action and visual effect were spatially compatible in one half of the experiment and spatially incompatible in the other half. Irrespective of whether effects were predicted by target stimuli in addition to participants' actions, in both action modes, we observed anticipatory saccades towards the location of future effects. Importantly, neither the frequency, nor latency or amplitude of these anticipatory saccades significantly differed between forced choice and free choice action modes. Overall, our findings suggest that proactive effect monitoring of future action consequences, as reflected in anticipatory saccades, is comparable between forced choice and free choice action modes. |
Anastasia Pilat; Rebecca J. McLean; Anna Vanina; Robert A. Dineen; Irene Gottlob Clinical features and imaging characteristics in achiasmia Journal Article In: Brain Communications, vol. 5, no. 4, pp. 1–11, 2023. @article{Pilat2023,Achiasmia is a rare visual pathway maldevelopment with reduced decussation of the axons in the optic chiasm. Our aim was to investigate clinical characteristics, macular, optic nerve and brain morphology in achiasmia. A prospective, cross-sectional, observational study of 12 participants with achiasmia [8 males and 4 females; 29.6 ± 18.4 years (mean ± standard deviation)] and 24 gender-, age-, ethnicity- and refraction-matched healthy controls was done. Full ophthalmology assessment, eye movement recording, a high-resolution spectral-domain optical coherence tomography of the macular and optic disc, five-channel visual-evoked responses, eye movement recordings and MRI scans of the brain and orbits were acquired. Achiasmia was confirmed in all 12 clinical participants by visual-evoked responses. Visual acuity in this group was 0.63 ± 0.19 and 0.53 ± 0.19 for the right and left eyes, respectively; most participants had mild refractive errors. All participants with achiasmia had see-saw nystagmus and no measurable stereo vision. Strabismus and abnormal head position were noted in 58% of participants. Optical coherence tomography showed optic nerve hypoplasia with associated foveal hypoplasia in four participants. In the remaining achiasmia participants, macular changes with significantly thinner paracentral inner segment (P = 0.002), wider pit (P = 0.04) and visual flattening of the ellipsoid line were found. MRI demonstrated chiasmatic aplasia in 3/12 (25%), chiasmatic hypoplasia in 7/12 (58%) and a subjectively normal chiasm in 2/12 (17%). Septo-optic dysplasia and severe bilateral optic nerve hypoplasia were found in three patients with chiasmic aplasia/hypoplasia on MRI. In this largest series of achiasmia patients to date, we found for the first time that neuronal abnormalities occur already at the retinal level. Foveal changes, optic nerve hypoplasia and the midline brain anomaly suggest that these abnormalities could be part of the same spectrum, with different manifestations of events during foetal development occurring with varying severity. |
Megan Polden; Trevor J. Crawford Eye movement latency coefficient of variation as a predictor of cognitive impairment: An eye tracking study of cognitive impairment Journal Article In: Vision, vol. 7, no. 2, pp. 1–12, 2023. @article{Polden2023,Studies demonstrated impairment in the control of saccadic eye movements in Alzheimer's disease (AD) and people with mild cognitive impairment (MCI) when conducting the pro-saccade and antisaccade tasks. Research showed that changes in the pro and antisaccade latencies may be particularly sensitive to dementia and general executive functioning. These tasks show potential for diagnostic use, as they provide a rich set of potential eye tracking markers. One such marker, the coefficient of variation (CV), is so far overlooked. For biological markers to be reliable, they must be able to detect abnormalities in preclinical stages. MCI is often viewed as a predecessor to AD, with certain classifications of MCI more likely than others to progress to AD. The current study examined the potential of CV scores on pro and antisaccade tasks to distinguish participants with AD, amnestic MCI (aMCI), non-amnesiac MCI (naMCI), and older controls. The analyses revealed no significant differences in CV scores across the groups using the pro or antisaccade task. Antisaccade mean latencies were able to distinguish participants with AD and the MCI subgroups. Future research is needed on CV measures and attentional fluctuations in AD and MCI individuals to fully assess this measure's potential to robustly distinguish clinical groups with high sensitivity and specificity. |
Antonella Pomè; Sandra Tyralla; Eckart Zimmermann Altered oculomotor flexibility is linked to high autistic traits Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 1–12, 2023. @article{Pome2023,Autism is a multifaced disorder comprising sensory abnormalities and a general inflexibility in the motor domain. The sensorimotor system is continuously challenged to answer whether motion-contingent errors result from own movements or whether they are due to external motion. Disturbances in this decision could lead to the perception of motion when there is none and to an inflexibility with regard to motor learning. Here, we test the hypothesis that altered processing of gaze-contingent sensations are responsible for both the motor inflexibility and the sensory overload in autism. We measured motor flexibility by testing how strong participants adapted in a classical saccade adaptation task. We asked healthy participants, scored for autistic traits, to make saccades to a target that was displaced either in inward or in outward direction during saccade execution. The amount of saccade adaptation, that requires to shift the internal target representation, varied with the autistic symptom severity. The higher participants scored for autistic traits, the less they adapted. In order to test for visual stability, we asked participants to localize the position of the saccade target after they completed their saccade. We found the often-reported saccade-induced mislocalization in low Autistic Quotient (AQ) participants. However, we also found mislocalization in high AQ participants despite the absence of saccade adaptation. Our data suggest that high autistic traits are associated with an oculomotor inflexibility that might produce altered processing of trans-saccadic vision which might increase the perceptual overstimulation that is experienced in autism spectrum disorders (ASD). |
Jan Ole Radecke; Andreas Sprenger; Hannah Stöckler; Lisa Espeter; Mandy Josephine Reichhardt; Lara S. Thomann; Tim Erdbrügger; Yvonne Buschermöhle; Stefan Borgwardt; Till R. Schneider; Joachim Gross; Carsten H. Wolters; Rebekka Lencer Normative tDCS over V5 and FEF reveals practice-induced modulation of extraretinal smooth pursuit mechanisms, but no specific stimulation effect Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 1–15, 2023. @article{Radecke2023,The neural networks subserving smooth pursuit eye movements (SPEM) provide an ideal model for investigating the interaction of sensory processing and motor control during ongoing movements. To better understand core plasticity aspects of sensorimotor processing for SPEM, normative sham, anodal or cathodal transcranial direct current stimulation (tDCS) was applied over visual area V5 and frontal eye fields (FEF) in sixty healthy participants. The identical within-subject paradigm was used to assess SPEM modulations by practice. While no specific tDCS effects were revealed, within- and between-session practice effects indicate plasticity of top-down extraretinal mechanisms that mainly affect SPEM in the absence of visual input and during SPEM initiation. To explore the potential of tDCS effects, individual electric field simulations were computed based on calibrated finite element head models and individual functional localization of V5 and FEF location (using functional MRI) and orientation (using combined EEG/MEG) was conducted. Simulations revealed only limited electric field target intensities induced by the applied normative tDCS montages but indicate the potential efficacy of personalized tDCS for the modulation of SPEM. In sum, results indicate the potential susceptibility of extraretinal SPEM control to targeted external neuromodulation (e.g., personalized tDCS) and intrinsic learning protocols. |
Ralph S. Redden; Matthew D. Hilchey; Sinan Aslam; Jason Ivanoff; Raymond M. Klein Using speed and accuracy and the Simon Effect to explore the output form of inhibition of return Journal Article In: Vision, vol. 7, no. 1, pp. 1–13, 2023. @article{Redden2023,Inhibition of return (IOR) refers to slower responses to targets presented at previously cued locations. Contrasting target discrimination performance over various eye movement conditions has shown the level of activation of the reflexive oculomotor system determines the nature of the effect. Notably, an inhibitory effect of a cue nearer to the input end of the processing continuum is observed when the reflexive oculomotor system is actively suppressed, and an inhibitory effect nearer the output end of the processing continuum is observed when the reflexive oculomotor system is actively engaged. Furthermore, these two forms of IOR interact differently with the Simon effect. Drift diffusion modeling has suggested that two parameters can theoretically account for the speed-accuracy tradeoff rendered by the output-based form of IOR: increased threshold and decreased trial noise. In Experiment 1, we demonstrate that the threshold parameter best accounts for the output-based form of IOR by measuring it with intermixed discrimination and localization targets. Experiment 2 employed the response-signal methodology and showed that the output-based form has no effect on the accrual of information about the target's identity. These results converge with the response bias account for the output form of IOR. |
Peter Reddingius; Daniel S. Asfaw; Vera M. Mönter; Nicholas D. Smith; Pete R. Jones; David P. Crabb Data on eye movements of glaucoma patients with asymmetrical visual field loss during free viewing Journal Article In: Data in Brief, vol. 48, pp. 1–7, 2023. @article{Reddingius2023,This paper describes data from Asfaw at al. [1], which examined the eye movements of glaucoma patients (n=15) with pronounced asymmetrical vision loss (visual field loss worse in one eye). This allows for within-subject comparisons between the better and worse eye, thereby controlling for the effects of individual differences between patients. All patients had a clinical diagnosis of open angle glaucoma (OAG). Participants were asked to look at images of nature monocularly (free viewing; fellow eye patched) while gaze was recorded at 1000 Hz using a remote eye tracker (EyeLink 1000). Raw and processed eye tracking data are provided. In addition, clinical (visual acuity, contrast sensitivity and visual field) and demographic information (age, sex) are provided. |
Scott Roberts; Peter R. Kufahl; Rebecca J. Ryznar; Taylor Norris; Sagar Patel; K. Dean Gubler; Dean Paz; Greg Schwimer; Richard Besserman; Anthony J. LaPorta Start-of-day oculomotor screening demonstrates the effects of fatigue and rest during a total immersion training program Journal Article In: Surgery, vol. 174, no. 5, pp. 1193–1200, 2023. @article{Roberts2023,Background: Investigating changes in sleep and fatigue metrics during intensive surgical and trauma skills training, this study explored the dynamic association between oculomotor metrics and fatigue. Specifically, alterations in these relations over extended stress exposure, the influence of time of day, and the impact of fatigue exposure on sleep metrics were examined. Methods: Thirty-nine military medical students participated in 6 days of immersion, hyper-realistic, and high-stress experiential casualty training. Participants completed surveys assessing the state of sleepiness with oculomotor tests performed each morning and evening, analyzing eye movement and pupillary change to characterize fatigue. Participants wore Fitbit TM devices to measure overall time asleep and time in each sleep stage during the training. Results: Fitbit data showed increased average minutes in rapid eye movement, deep sleep, and less time in light sleep from day 1 to day 4. The microsaccade peak velocity-to-displacement ratio exhibited a morning decrease but not in afternoon sessions, indicating repeated but temporary effects of accumulated fatigue. There were no findings regarding pupil reactivity to illumination changes. Conclusion: This study describes characteristics of fatigue measured by rapid and individually calibrated oculomotor tests. It demonstrates oculomotor relationships to fatigue in start-of-day testing, providing a direction for timing for optimal fatigue testing. These data suggest that improved sleep could signal resilience to fatigue during afternoon testing. Further investigation with more participants and longer duration is warranted. A deeper understanding of the interrelationships between training, sleep, and fatigue could improve surgical and military fitness. |
Cristina Rovira-Gay; Clara Mestre; Marc Argiles; Valldeflors Vinuela-Navarro; Jaume Pujol Feasibility of measuring fusional vergence amplitudes objectively Journal Article In: PLoS ONE, vol. 18, pp. 1–14, 2023. @article{RoviraGay2023,Two tests to measure fusional vergence amplitudes objectively were developed and validated against the two conventional clinical tests. Forty-nine adults participated in the study. Participants' negative (BI, base in) and positive (BO, base out) fusional vergence amplitudes at near were measured objectively in an haploscopic set-up by recording eye movements with an EyeLink 1000 Plus (SR Research). Stimulus disparity changed in steps or smoothly mimicking a prim bar and a Risley prism, respectively. Break and recovery points were determined offline using a custom Matlab algorithm for the analysis of eye movements. Fusional vergence amplitudes were also measured with two clinical tests using a Risley prism and a prism bar. A better agreement between tests was found for the measurement of BI than for BO fusional vergence amplitudes. The means ± SD of the differences between the BI break and recovery points measured with the two objective tests were -1.74 ± 3.35 PD and -1.97 ± 2.60 PD, respectively, which were comparable to those obtained for the subjective tests. For the BO break and recovery points, although the means of the differences between the two objective tests were small, high variability between subjects was found (0.31 ± 6.44 PD and -2.84 ± 7.01 PD, respectively). This study showed the feasibility to measure fusional vergence amplitudes objectively and overcome limitations of the conventional subjective tests. However, these tests cannot be used interchangeably due to their poor agreement. |
Shreshth Saxena; Lauren K. Fink; Elke B. Lange Deep learning models for webcam eye tracking in online experiments Journal Article In: Behavior Research Methods, pp. 1–17, 2023. @article{Saxena2023a,Eye tracking is prevalent in scientific and commercial applications. Recent computer vision and deep learning methods enable eye tracking with off-the-shelf webcams and reduce dependence on expensive, restrictive hardware. However, such deep learning methods have not yet been applied and evaluated for remote, online psychological experiments. In this study, we tackle critical challenges faced in remote eye tracking setups and systematically evaluate appearance-based deep learning methods of gaze tracking and blink detection. From their own homes and laptops, 65 participants performed a battery of eye tracking tasks including (i) fixation, (ii) zone classification, (iii) free viewing, (iv) smooth pursuit, and (v) blink detection. Webcam recordings of the participants performing these tasks were processed offline through appearance-based models of gaze and blink detection. The task battery required different eye movements that characterized gaze and blink prediction accuracy over a comprehensive list of measures. We find the best gaze accuracy to be 2.4° and precision of 0.47°, which outperforms previous online eye tracking studies and reduces the gap between laboratory-based and online eye tracking performance. We release the experiment template, recorded data, and analysis code with the motivation to escalate affordable, accessible, and scalable eye tracking that has the potential to accelerate research in the fields of psychological science, cognitive neuroscience, user experience design, and human–computer interfaces. |
Yasuo Terao; Yoshiko Nomura; Hideki Fukuda; Okihide Hikosaka; Kazue Kimura; Shun-ichi Matsuda; Akihiro Yugeta; Francesco Fisicaro; Kyoko Hoshino; Yoshikazu Ugawa The pathophysiology of Gilles de la Tourette Syndrome: Changes in saccade performance by low-dose L-Dopa and dopamine receptor blockers Journal Article In: Brain Sciences, vol. 13, no. 12, pp. 1–23, 2023. @article{Terao2023,Aim: To elucidate the pathophysiology of Gilles de la Tourette syndrome (GTS), which is associated with prior use of dopamine receptor antagonists (blockers) and treatment by L-Dopa, through saccade performance. Method: In 226 male GTS patients (5–14 years), we followed vocal and motor tics and obsessive–compulsive disorder (OCD) after discontinuing blockers at the first visit starting with low-dose L-Dopa. We recorded visual- (VGS) and memory-guided saccades (MGS) in 110 patients and 26 normal participants. Results: At the first visit, prior blocker users exhibited more severe vocal tics and OCD, but not motor tics, which persisted during follow-up. Patients treated with L-Dopa showed greater improvement of motor tics, but not vocal tics and OCD. Patients with and without blocker use showed similarly impaired MGS performance, while patients with blocker use showed more prominently impaired inhibitory control of saccades, associated with vocal tics and OCD. Discussion: Impaired MGS performance suggested a mild hypodopaminergic state causing reduced direct pathway activity in the (oculo-)motor loops of the basal ganglia–thalamocortical circuit. Blocker use may aggravate vocal tics and OCD due to disinhibition within the associative and limbic loops. The findings provide a rationale for discouraging blocker use and using low-dose L-Dopa in GTS. |
Lonneke Teunissen; Luc P. J. Selen; W. Pieter Medendorp Abrupt, but not gradual, motor adaptation biases saccadic target selection Journal Article In: Journal of Neurophysiology, vol. 129, no. 3, pp. 733–748, 2023. @article{Teunissen2023,Decisions between potential motor actions are influenced by their costs, but costs change when movements are adapted. Using a saccadic target selection task, we show that target preference shifts after abrupt, but not after gradual adaptation. We suggest that this difference emerges because abrupt adaptation results in target remapping, and thus directly influences cost calculations, whereas gradual adaptation is mainly driven by corrections to a forward model that is not involved in cost calculations.Motor costs influence movement selection. These costs could change when movements are adapted in response to errors. When the motor system attributes the encountered errors to an external cause, appropriate movement selection requires an update of the movement goal, which prompts the selection of a different control policy. However, when errors are attributed to an internal cause, the initially selected control policy could remain unchanged, but the internal forward model of the body needs to be updated, resulting in an online correction of the movement. We hypothesized that external attribution of errors leads to the selection of a different control policy, and thus to a change in the expected cost of movements. This should also affect subsequent motor decisions. Conversely, internal attribution of errors may (initially) only evoke online corrections, and thus is expected to leave the motor decision process unchanged. We tested this hypothesis using a saccadic adaptation paradigm, designed to change the relative motor cost of two targets. Motor decisions were measured using a target selection task between the two saccadic targets before and after adaptation. Adaptation was induced by either abrupt or gradual perturbation schedules, which are thought to induce more external or internal attribution of errors, respectively. By taking individual variability into account, our results show that saccadic decisions shift toward the least costly target after adaptation, but only when the perturbation is abruptly, and not gradually, introduced. We suggest that credit assignment of errors not only influences motor adaptation but also subsequent motor decisions.NEW & NOTEWORTHY Decisions between potential motor actions are influenced by their costs, but costs change when movements are adapted. Using a saccadic target selection task, we show that target preference shifts after abrupt, but not after gradual adaptation. We suggest that this difference emerges because abrupt adaptation results in target remapping, and thus directly influences cost calculations, whereas gradual adaptation is mainly driven by corrections to a forward model that is not involved in cost calculations. |
Sandra Tyralla; Antonella Pomè; Eckart Zimmermann Motor recalibration of visual and saccadic maps Journal Article In: Proceedings of the Royal Society B: Biological Sciences, vol. 290, no. 1994, pp. 1–10, 2023. @article{Tyralla2023,How does the brain maintain an accurate visual representation of external space? Movement errors following saccade execution provide sufficient information to recalibrate motor and visual space. Here, we asked whether spatial information for vision and saccades is processed in shared or in separate resources. We used saccade adaptation to modify both, saccade amplitudes and visual mislocalization. After saccade adaptation was induced, we compared participants' saccadic and perceptual localization before and after we inserted 'no error' trials. In these trials, we clamped the post-saccadic error online to the predicted endpoints of saccades. In separate experiments, we either annulled the retinal or the prediction error. We also varied the number of 'no error' trials across conditions. In all conditions, we found that saccade adaptation remained undisturbed by the insertion of 'no error' trials. However, mislocalization decreased as a function of the number of trials in which zero retinal error was displayed. When the prediction error was clamped to zero, no mislocalization was observed at all. The results demonstrate the post-saccadic error is used separately to recalibrate visual and saccadic space. |
Elle Heusden; Christian N. L. Olivers; Mieke Donk The eyes prefer targets nearby fixation: Quantifying eccentricity-dependent attentional biases in oculomotor selection Journal Article In: Vision Research, vol. 205, pp. 1–11, 2023. @article{Heusden2023,An important function of peripheral vision is to provide the target of the next eye movement. Here we investigate the extent to which the eyes are biased to select a target closer to fixation over one further away. Participants were presented with displays containing two identical singleton targets and were asked to move their eyes to either one of them. The targets could be presented at three different eccentricities relative to central fixation. In one condition both singletons were presented at the same eccentricity, providing an estimate of the speed of selection at each of the eccentricities. The saccadic latency distributions from this same-eccentricity condition were then used to predict the selection bias when both targets were presented at different eccentricities. The results show that when targets are presented at different eccentricities, participants are biased to select the item closest to fixation. This eccentricity-based bias was considerably stronger than predicted on the basis of saccadic latency distributions in the same-eccentricity condition. This rules out speed of processing per se as a sole explanation for such a bias. Instead, the results are consistent with attentional competition being weighted in favour of items close to fixation. |
Valldeflors Vinuela-Navarro; Joan Goset; Mikel Aldaba; Clara Mestre; Cristina Rovira-Gay; Neus Cano; Mar Ariza; Bàrbara Delàs; Maite Garolera; Meritxell Vilaseca Eye movements in patients with post-COVID condition Journal Article In: Biomedical Optics Express, vol. 14, no. 8, pp. 1–14, 2023. @article{VinuelaNavarro2023,Eye movement control is impaired in some neurological conditions, but the impact of COVID-19 on eye movements remains unknown. This study aims to investigate differences in oculomotor function and pupil response in individuals who suffer post-COVID-19 condition (PCC) with cognitive deficits. Saccades, smooth pursuit, fixation, vergence and pupillary response were recorded using an eye tracker. Eye movements and pupil response parameters were computed. Data from 16 controls, 38 COVID mild (home recovery) and 19 COVID severe (hospital admission) participants were analyzed. Saccadic latencies were shorter in controls (183 ± 54 ms) than in COVID mild (236 ± 83 ms) and COVID severe (227 ± 42 ms) participants (p = 0.017). Fixation stability was poorer in COVID mild participants (Bivariate Contour Ellipse Area of 0.80 ± 1.61° 2 vs 0.36 ± 0.65 ° 2 for controls |
A. C. L. Vrijling; M. J. Boer; R. J. Renken; J. B. C. Marsman; A. Grillini; C. E. Petrillo; J. Heutink; N. M. Jansonius; F. W. Cornelissen Stimulus contrast, pursuit mode, and age strongly influence tracking performance on a continuous visual tracking task Journal Article In: Vision Research, vol. 205, pp. 1–11, 2023. @article{Vrijling2023,Human observers tend to naturally track moving stimuli. This tendency may be exploited towards an intuitive means of screening visual function as an impairment induced reduction in stimulus visibility will decrease tracking performance. Yet, to be able to detect subtle impairments, stimulus contrast is critical. If too high, the decrease in performance may remain undetected. Therefore, for this approach to become reliable and sensitive, we need a detailed understanding of how age, stimulus contrast, and the type of stimulus movement affect continuous tracking performance. To do so, we evaluated how well twenty younger and twenty older participants tracked a semi-randomly moving stimulus (Goldmann size III, 0.43 degrees of visual angle), presented at five contrast levels (5%-10%-20%-40%-80%). The stimulus could move smoothly only (smooth pursuit mode) or in alternation with displacements (saccadic pursuit mode). Additionally, we assessed static foveal and peripheral contrast thresholds. For all participants, tracking performance improved with increasing contrast in both pursuit modes. To reach threshold performance levels, older participants required about twice as much contrast (20% vs. 10% and 40% vs. 20% in smooth and saccadic modes respectively). Saccadic pursuit detection thresholds correlated significantly with static peripheral contrast thresholds (rho = 0.64). Smooth pursuit detection thresholds were uncorrelated with static foveal contrast thresholds (rho = 0.29). We conclude that continuous visual stimulus tracking is strongly affected by stimulus contrast, pursuit mode, and age. This provides essential insights that can be applied towards new and intuitive approaches of screening visual function. |
Ilja Wagner; Alexander C. Sch€utz Interaction of dynamic error signals in saccade adaptation Journal Article In: Journal of Neurophysiology, vol. 129, no. 3, pp. 717–732, 2023. @article{Wagner2023,Motor adaptation maintains movement accuracy. To evaluate movement accuracy, motor adaptation relies on an error signal, generated by the movement target, while suppressing error signals from irrelevant objects in the vicinity. Previous work used static testing environments, where all information required to evaluate movement accuracy was available simultaneously. Using saccadic eye movements as a model for motor adaptation, we tested how movement accuracy is maintained in dynamic environments, where the availability of conflicting error signals varied over time. Participants made a vertical saccade toward a target (either a small square or a large ring). Upon saccade detection, two candidate stimuli were shown left and right of the target, and participants were instructed to discriminate a feature on one of the candidates. Critically, candidate stimuli were presented sequentially, and saccade adaptation, thus, had to resolve a conflict between a task-relevant and a task-irrelevant error signal that were separated in space and time. We found that the saccade target influenced several aspects of oculomotor learning. In presence of a small target, saccade adaptation evaluated movement accuracy based on the first available error signal after the saccade, irrespective of its task relevance. However, a large target not only allowed for greater flexibility when evaluating movement accuracy, but it also promoted a stronger contribution of strategic behavior when compensating inaccurate saccades. Our results demonstrate how motor adaptation maintains movement accuracy in dynamic environments, and how properties of the visual environment modulate the relative contribution of different learning processes. |
Sonja Walcher; Živa Korda; Christof Körner; Mathias Benedek The effects of type and workload of internal tasks on voluntary saccades in a targetdistractor saccade task Journal Article In: PLoS ONE, vol. 18, pp. 1–27, 2023. @article{Walcher2023,When we engage in internally directed cognition, like doing mental arithmetic or mind wandering, fewer cognitive resources are assigned for other activities like reacting to perceptual input-an effect termed perceptual decoupling. However, the exact conditions under which perceptual decoupling occurs and its underlying cognitive mechanisms are still unclear. Hence, the present study systematically manipulated the task type (arithmetic, visuospatial) and workload (control, low, high) of the internal task in a within-subject design and tested its effects on voluntary saccades in a target-distractor saccade task. As expected, engagement in internal tasks delayed saccades to the target. This effect was moderated by time, task, and workload: The delay was largest right after internal task onset and then decreased, potentially reflecting the intensity of internal task demands. Saccades were also more delayed for the high compared to the low workload condition in the arithmetic task, whereas workload conditions had similarly high effects in the visuospatial task. Findings suggests that perceptual decoupling of eye behavior gradually increases with internal demands on general resources and that perceptual decoupling is specifically sensitive to internal demands on visuospatial resources. The latter may be mediated by interference due to eye behavior elicited by the internal task itself. Internal tasks did not affect the saccade latencydeviation trade-off, indicating that while the internal tasks delayed the execution of the saccade, the perception of the saccade stimuli and spatial planning of the saccade continued unaffected in parallel to the internal tasks. Together, these findings shed further light on the specific mechanisms underlying perceptual decoupling by suggesting that perceptual decoupling of eye behavior increases as internal demands on cognitive resources overlap more strongly with demands of the external task. |
Josefine Waldthaler; Lena Stock; Charlotte Krüger-Zechlin; Zain Deeb; Lars Timmermann Cluster analysis reveals distinct patterns of saccade impairment and their relation to cognitive profiles in Parkinson's disease Journal Article In: Journal of Neuropsychology, vol. 17, no. 2, pp. 251–263, 2023. @article{Waldthaler2023b,Saccade performance has been reported to be altered in Parkinson's disease (PD), however, with a large variability between studies as both motor and cognitive impairment interfere with oculomotor control. The aim of this study was to identify different patterns in saccade alterations in PD using a data-driven approach and to explore their relationship with cognitive phenotypes. Sixty-one participants with PD and 25 controls performed eye-tracking (horizontal and vertical prosaccades, antisaccades) and neuropsychological testing. Hierarchical cluster analysis was applied to the eye-tracking data to subsequently compare the clusters based on demographical, clinical and cognitive characteristics. The three identified clusters of saccade alterations differed in cognitive profiles from healthy controls, but not in PD-related motor symptoms or demographics. The rate of directive errors in the antisaccade task was increased in clusters 1 and 2. Further, cluster 1 was defined by a general disinhibition of reflexive saccades and executive dysfunction in the neuropsychological evaluation. In cluster 2, prolonged saccade latencies and hypometria were accompanied by multidomain cognitive impairment. The cluster 3 showed increased antisaccade latency and vertical hypometria despite lack of evidence for cognitive impairment. Our results suggest that there may be at least two opposing patterns of saccade alterations associated with cognitive impairment in PD, which may explain some of the contradictory results of previous studies. |
Chin-An Wang; Neil G. Muggleton; Yi-Hsuan Chang; Cesar Barquero; Ying-Chun Kuo Time-on-task effects on human pupillary and saccadic metrics after theta burst transcranial magnetic stimulation over the frontal eye field Journal Article In: IBRO Neuroscience Reports, vol. 15, pp. 364–375, 2023. @article{Wang2023c,Pupil size undergoes constant changes primarily influenced by ambient luminance. These changes are referred to as the pupillary light reflex (PLR), where the pupil transiently constricts in response to light. PLR kinematics provides valuable insights into autonomic nervous system function and have significant clinical applications. Recent research indicates that attention plays a role in modulating the PLR, and the circuit involving the frontal eye field (FEF) and superior colliculus is causally involved in controlling this pupillary modulation. However, there is limited research exploring the role of the human FEF in these pupillary responses, and its impact on PLR metrics remains unexplored. Additionally, although the protocol of continuous theta-burst stimulation (cTBS) is well-established, the period of disruption after cTBS is yet to be examined in pupillary responses. Our study aimed to investigate the effects of FEF cTBS on pupillary and saccadic metrics in relation to time spent performing a task (referred to as time-on-task). We presented a bright stimulus to induce the PLR in visual- and memory-delay saccade tasks following cTBS over the right FEF or vertex. FEF cTBS, compared to vertex cTBS, resulted in decreased baseline pupil size, peak constriction velocities, and amplitude. Furthermore, the time-on-task effects on baseline pupil size, peak amplitude, and peak time differed between the two stimulation conditions. In contrast, the time-on-task effects on saccadic metrics were less pronounced between the two conditions. In summary, our study provides the first evidence that FEF cTBS affects human PLR metrics and that these effects are modulated by time-on-task. |
Scott N. J. Watamaniuk; Jeremy B. Badler; Stephen J. Heinen Peripheral targets attenuate miniature eye movements during fixation Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 1–9, 2023. @article{Watamaniuk2023,Fixating a small dot is a universal technique for stabilizing gaze in vision and eye movement research, and for clinical imaging of normal and diseased retinae. During fixation, microsaccades and drifts occur that presumably benefit vision, yet microsaccades compromise image stability and usurp task attention. Previous work suggested that microsaccades and smooth pursuit catch-up saccades are controlled by similar mechanisms. This, and other previous work showing fewer catch-up saccades during smooth pursuit of peripheral targets suggested that a peripheral target might similarly mitigate microsaccades. Here, human observers fixated one of three stimuli: a small central dot, the center of a peripheral, circular array of small dots, or a central/peripheral stimulus created by combining the two. The microsaccade rate was significantly lower with the peripheral array than with the dot. However, inserting the dot into the array increased the microsaccade rate to single-dot levels. Drift speed also decreased with the peripheral array, both with and without the central dot. Eye position variability was higher with the array than with the composite stimulus. The results suggest that analogous to the foveal pursuit, foveating a stationary target engages the saccadic system likely compromising retinal-image stability. In contrast, fixating a peripheral stimulus improves stability, thereby affording better retinal imaging and releasing attention for experimental tasks. |
Carola Bloch; Shivakumar Viswanathan; Ralf Tepest; Mathis Jording; Christine M. Falter-Wagner; Kai Vogeley Differentiated, rather than shared, strategies for time-coordinated action in social and non-social domains in autistic individuals Journal Article In: Cortex, vol. 166, pp. 207–232, 2023. @article{Bloch2023,Autism spectrum disorder (ASD) is a neurodevelopmental condition with a highly heterogeneous adult phenotype that includes social and non-social behavioral characteristics. The link between the characteristics assignable to the different domains remains unresolved. One possibility is that social and non-social behaviors in autism are modulated by a common underlying deficit. However, here we report evidence supporting an alternative concept that is individual-centered rather than deficit-centered. Individuals are assumed to have a distinctive style in the strategies they adopt to perform social and non-social tasks with these styles presumably being structured differently between autistic individuals and typically-developed (TD) individuals. We tested this hypothesis for the execution of time-coordinated (synchronized) actions. Participants performed (i) a social task that required synchronized gaze and pointing actions to interact with another person, and (ii) a non-social task that required finger-tapping actions synchronized to periodic stimuli at different time-scales and sensory modalities. In both tasks, synchronization behavior differed between ASD and TD groups. However, a principal component analysis of individual behaviors across tasks revealed associations between social and non-social features for the TD persons but such cross–domain associations were strikingly absent for autistic individuals. The highly differentiated strategies between domains in ASD are inconsistent with a general synchronization deficit and instead highlight the individualized developmental heterogeneity in the acquisition of domain-specific behaviors. We propose a cognitive model to help disentangle individual-centered from deficit-centered effects in other domains. Our findings reinforce the importance to identify individually differentiated phenotypes to personalize autism therapies. |
Florence Blondiaux; Louisien Lebrun; Bernard J. Hanseeuw; Frédéric Crevecoeur Impairments of saccadic and reaching adaptation in essential tremor are linked to movement execution Journal Article In: Journal of Neurophysiology, vol. 130, no. 5, pp. 1092–1102, 2023. @article{Blondiaux2023,Essential tremor (ET) is a neurological disorder characterized by involuntary oscillations of the limbs. Previous studies have hypothesized that ET is a cerebellar disorder and reported impairments in motor adaptation. However, recent advances have highlighted that motor adaptation involves several components linked to anticipation and control, all dependent on cerebellum. We studied the contribution of both components in adaptation to better understand the adaptation impairments observed in ET from a behavioral perspective. To address this question, we investigated behavioral markers of adaptation in ET patients (n = 20) and age-matched neurologically intact volunteers (n = 20) in saccadic and upper limb adaptation tasks, probing compensation for target jumps and for velocity-dependent force fields, respectively. We found that both groups adapted their movements to the novel contexts; however, ET patients adapted to a lesser extent compared with neurologically intact volunteers. Importantly, components of the movement linked to anticipation were preserved in the ET group, whereas components linked to movement execution appeared responsible for the adaptation deficit in this group. Altogether, our results suggest that execution deficits may be a specific functional consequence of the alteration of neural pathways associated with ET.NEW & NOTEWORTHY We tested essential tremor patients' adaptation abilities in classical tasks including saccadic adaptation to target jumps and reaching adaptation to force field disturbances. Patients' adaptation was present but impaired in both tasks. Interestingly, the deficits were mainly present during movement execution, whereas the anticipatory components of movements were similar to neurologically intact volunteers. These findings reinforce the hypothesis of a cerebellar origin for essential tremor and detail the motor adaptation impairments previously found in this disorder. |
Zoé Bollen; Louise Kauffmann; Nathalie Guyader; Carole Peyrin; Pierre Maurage Does alcohol automatically capture drinkers' attention? Exploration through an eye-tracking saccadic choice task Journal Article In: Psychopharmacology, vol. 240, no. 2, pp. 271–282, 2023. @article{Bollen2023,Rationale: Dominant theoretical models postulate the presence of an automatic attentional bias (AB) towards alcohol-related stimuli in alcohol use disorder, such AB constituting a core feature of this disorder. An early alcohol AB has been documented in subclinical populations such as binge drinking (i.e., a drinking pattern prevalent in youth and characterized by repeated alternation between alcohol intoxications and withdrawals, generating cerebral consequences). However, the automatic nature of AB remains to be established. Objectives: We investigated the automatic nature of AB in binge drinkers through the saccadic choice task. This eye-tracking paradigm consistently highlights the extremely fast and involuntary saccadic responses elicited by faces in humans, relative to other object categories. Through an alcohol-related adaptation of the saccadic choice task, we tested whether the early and automatic capture of attentional resources elicited by faces can also be found for alcohol-related stimuli in binge drinkers, as predicted by theoretical models. Methods: Forty-three binge drinkers and 44 control participants performed two versions of the saccadic choice task. In the original version, two images (a face, a vehicle) were displayed on the left and right side of the screen respectively. Participants had to perform a saccade as fast as possible towards the target stimulus (either face or vehicle). In the alcohol-related version, the task was identical, but the images were an alcoholic beverage and a non-alcoholic stimulus. Results: We replicated the automatic attraction towards faces in both groups, as faces generated higher saccadic accuracy, speed, and amplitude than vehicles, as well as higher corrective saccade proportion. Concerning the alcohol-related adaptation of the task, groups did not differ for the accuracy, speed, and amplitude of the first saccade towards alcohol. However, binge drinkers differed from controls regarding the proportion of corrective saccade towards non-alcoholic stimuli after an error saccade towards alcohol, suggesting the presence of an alcohol disengagement bias specific to binge drinkers. Conclusions: Alcohol-related AB in binge drinkers is not characterized by an early and automatic hijacking of attention towards alcohol. This AB rather relies on later and more controlled processing stages, namely a difficulty to disengage attentional resources from alcohol-related stimuli. |
Zoé Bollen; Arthur Pabst; Nicolas Masson; Samuel Suárez-Suárez; Carina Carbia; Pierre Maurage Tell me how you feel, I will tell you what you look at: Impact of mood and craving on alcohol attentional bias in binge drinking Journal Article In: Journal of Psychopharmacology, vol. 37, no. 5, pp. 498–509, 2023. @article{Bollen2023a,Background: Alcohol-related attentional bias (AB) is thought to play a key role in the emergence and maintenance of excessive alcohol use. Recent models suggest that AB, classically considered as a permanent feature in alcohol use disorders, is rather modulated by temporary motivational states. Aims: We explored the influence of current mood and craving on AB in binge drinking, through a mood induction procedure combined with eye-tracking measures of AB. Methods: In Experiment 1, we measured AB (visual probe task with eye-tracking measures) among binge drinkers (n = 48) and light drinkers (n = 32) following positive, negative and neutral mood inductions. Participants reported subjective craving and mood before/after induction. In Experiment 2, we measured AB among the same binge drinkers compared with 29 moderate drinkers following alcohol-related negative, non-alcohol-related negative and neutral mood inductions. Results: In Experiment 1, induced negative mood and group positively predicted subjective craving, which was positively associated with AB. We found no effect of induced positive mood nor a direct mood-AB association. In Experiment 2, the relationships AB presented with both induced negative mood and group were again mediated by craving. Inducing alcohol-related negative mood did not modify the mood-craving association. Conclusions: Alcohol-related AB is not a stable binge drinking characteristic but rather varies according to transient motivational (i.e., craving) and emotional (i.e., negative mood) states. This study provides important insights to better understand AB in subclinical populations and emphasizes the importance of considering motivational and affective states as intercorrelated, to offer multiple ways to reduce excessive alcohol use. |
Lou Anne E. Boyd; Jazette Johnson; Franceli Cibrian; Deanna Hughes; Eliza Delpizzo-Cheng; Karen Lotich; Sara Jones; Hollis Pass; Viseth Sean; Gillian Hayes Global filter: Augmenting images to support seeing the "big picture" for people with local lnterference Journal Article In: ACM Transactions on Computer-Human Interaction, vol. 30, no. 3, pp. 1–28, 2023. @article{Boyd2023,Some neurodivergent people prioritize visual details over the "big picture". While excellent attention to detail has many advantages, some contexts require the rapid integration of global and local information. A local processing style can be so strong that local details interfere with the fluid integration of global information required for processing of information rapidly displayed on user interfaces. This disconnect between context of an interaction and processing style can be termed local interference. Personalization of visual stimuli can promote a more accessible computing experience. We describe how technological interventions can support shifting of visual attention from local to global features to make them more accessible. We present two empirical studies. One study with one autistic adult revealed a significant shift in eye gaze fixation, and the other study with 20 autistic children revealed filters that visually emphasize primary aspects encouraged more global comments about the image content. |
Laura B. Bragdon; Jacob A. Nota; Goi Khia Eng; Nicolette Recchia; Pearl Kravets; Katherine A. Collins; Emily R. Stern Failures of urge suppression in obsessive-compulsive disorder: Behavioral modeling using a blink suppression task Journal Article In: Journal of Obsessive-Compulsive and Related Disorders, vol. 38, pp. 1–10, 2023. @article{Bragdon2023,Many individuals with obsessive-compulsive disorder (OCD) report sensory-based urges (e.g. ‘not-just-right experiences') in addition to, or instead of, concrete fear-based obsessions. These sensations may be comparable to normative “urges-for-action” (UFA), such as the urge to blink. While research has identified altered functioning of brain regions related to UFA in OCD, little is known about behavioral patterns of urge suppression in the disorder. Using an urge-to-blink task as a model for sensory-based urges, this study compared failures of urge suppression between OCD patients and controls by measuring eyeblinks during 60-s blocks of instructed blink suppression. Cox shared frailty models estimated the hazard of first blinks during each 60-s block and recurrent blinks following each initial erroneous blink. OCD patients demonstrated a higher hazard of first and recurrent blinks compared to controls, suggesting greater difficulty resisting repetitive sensory-based urges. Within OCD, relationships between task outcomes and symptom severity were inconsistent. Findings provide support for a deficit in delaying initial urge-induced actions and terminating subsequent actions in OCD, which is not clearly related to clinical heterogeneity. Elucidating the nature of behavioral resistance to urges is relevant for informing conceptualizations of obsessive-compulsive psychopathology and optimizing treatment outcomes. |
Christina Buhl; Anca Sfärlea; Johanna Loechner; Kornelija Starman-Wöhrle; Elske Salemink; Gerd Schulte-Körne; Belinda Platt Biased maintenance of attention on sad faces in Clinically depressed youth: An eye-tracking study Journal Article In: Child Psychiatry and Human Development, vol. 54, no. 1, pp. 189–201, 2023. @article{Buhl2023,The role of negative attention biases (AB), central to cognitive models of adult depression, is yet unclear in youth depression. We investigated negative AB in depressed compared to healthy youth and tested whether AB are more pronounced in depressed than at-risk youth. Negative AB was assessed for sad and angry faces with an eye-tracking paradigm [Passive Viewing Task (PVT)] and a behavioural task [Visual Search Task (VST)], comparing three groups of 9–14-year-olds: youth with major depression (MD; n = 32), youth with depressed parents (high-risk; HR; n = 49) and youth with healthy parents (low-risk; LR; n = 42). The PVT revealed MD participants to maintain attention longer on sad faces compared to HR, but not LR participants. This AB correlated positively with depressive symptoms. The VST revealed no group differences. Our results provide preliminary evidence for a negative AB in maintenance of attention on disorder-specific emotional information in depressed compared to at-risk youth. |
Olivia G. Calancie; Ashley C. Parr; Don C. Brien; Jeff Huang; Isabell C. Pitigoi; Brian C. Coe; Linda Booij; Sarosh Khalid-Khan; Douglas P. Munoz In: Frontiers in Neuroscience, vol. 17, pp. 1–18, 2023. @article{Calancie2023,Shifting motor actions from reflexively reacting to an environmental stimulus to predicting it allows for smooth synchronization of behavior with the outside world. This shift relies on the identification of patterns within the stimulus – knowing when a stimulus is predictable and when it is not – and launching motor actions accordingly. Failure to identify predictable stimuli results in movement delays whereas failure to recognize unpredictable stimuli results in early movements with incomplete information that can result in errors. Here we used a metronome task, combined with video-based eye-tracking, to quantify temporal predictive learning and performance to regularly paced visual targets at 5 different interstimulus intervals (ISIs). We compared these results to the random task where the timing of the target was randomized at each target step. We completed these tasks in female pediatric psychiatry patients (age range: 11–18 years) with borderline personality disorder (BPD) symptoms, with (n = 22) and without (n = 23) a comorbid attention-deficit hyperactivity disorder (ADHD) diagnosis, against controls (n = 35). Compared to controls, BPD and ADHD/BPD cohorts showed no differences in their predictive saccade performance to metronome targets, however, when targets were random ADHD/BPD participants made significantly more anticipatory saccades (i.e., guesses of target arrival). The ADHD/BPD group also significantly increased their blink rate and pupil size when initiating movements to predictable versus unpredictable targets, likely a reflection of increased neural effort for motor synchronization. BPD and ADHD/BPD groups showed increased sympathetic tone evidenced by larger pupil sizes than controls. Together, these results support normal temporal motor prediction in BPD with and without ADHD, reduced response inhibition in BPD with comorbid ADHD, and increased pupil sizes in BPD patients. Further these results emphasize the importance of controlling for comorbid ADHD when querying BPD pathology. |
Devonte Campbell; Bernadette Ann Murphy; James Burkitt; Nicholas La Delfa; Praveen Sanmugananthan; Ushani Ambalavanar; Paul Yielder Cervico-ocular and vestibulo-ocular reflexes in subclinical neck pain and healthy individuals: A cross-sectional study Journal Article In: Brain Sciences, vol. 13, no. 11, pp. 1–15, 2023. @article{Campbell2023,Alterations in neck sensory input from recurrent neck pain (known as subclinical neck pain (SCNP)) result in disordered sensorimotor integration (SMI). The cervico-ocular (COR) and vestibulo-ocular (VOR) reflexes involve various neural substrates but are coordinated by the cerebellum and reliant upon proprioceptive feedback. Given that proprioception and cerebellar processing are impaired in SCNP, we sought to determine if COR or VOR gain is also altered. COR and VOR were assessed using an eye-tracking device in 20 SCNP (9 M and 11 F; 21.8 (SD = 2.35) years) and 17 control (7 M and 10 F; 22.40 (SD = 3.66) years) participants. COR gain (10 trials): A motorized chair rotated the trunk at a frequency of 0.04 Hz and an amplitude of 5° while participants gazed at a circular target that disappeared after three seconds. VOR gain (30 trials): Rapid bilateral head movements away from a disappearing circular target while eyes fixated on the last observed target. Independent t-tests on COR and VOR gain were performed. SCNP had a significantly larger COR gain (p = 0.006) and smaller VOR gain (p = 0.487) compared to healthy controls. The COR group differences suggest an association between proprioceptive feedback and SMI, indicating COR may be a sensitive marker of altered cerebellar processing. |
Dinis Catronas; José Sousa; Ana Rita Batista; Nathércia Lima Torres; Ana Mesquita; Vasiliki Folia; Susana Silva Duration perception for visual stimuli is impaired in dyslexia but deficits in visual processing may not be the culprits Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 1–13, 2023. @article{Catronas2023,Dyslexics underperform controls in estimating and comparing time intervals defined by visual stimuli. Accuracy in vision-based duration perception requires efficient processing of visual events because these will define the onset and offset of time intervals. Since dyslexics have difficulties processing dimensions of visual stimuli like luminance contrasts and motion, we do not know the extent to which these visual deficits are responsible for their difficulties in judging time intervals. To address this gap, we asked adults with dyslexia and matched controls to perform an interval comparison task involving five different types of visual stimuli with different levels of challenge regarding luminance contrasts and motion. If the expected disadvantage of dyslexics in visual duration perception increased for stimuli requiring increased luminance or motion processing, this would indicate that visual processing plays a role. Results showed poorer time discrimination in dyslexics, but this disadvantage did not change according to stimulus type. Complementary analyses of oculomotor behavior during the task suggested that the poorer timing performance of dyslexics may relate instead to attention and/or engagement with the task. Our findings strengthen the evidence in favor of visual duration perception deficits in dyslexia, but not the hypothesis that these result from purely visual problems. |
Melinda Y. Chang; Mark S. Borchert Comparison of eye tracking and Teller acuity cards for visual acuity assessment in pediatric cortical/cerebral visual impairment (CVI) Journal Article In: American Journal of Ophthalmology, vol. 260, pp. 115–121, 2023. @article{Chang2023,•PURPOSE: To compare eye tracking and Teller acuity cards (TAC) for assessment of visual acuity in children with cortical, or cerebral, visual impairment (CVI). •DESIGN: Reliability and validity study. • METHODS: We recruited 41 children with CVI from a single academic pediatric neuro-ophthalmology clinic. All children performed eye tracking to measure visual acuity, and 26 children completed TAC assessment by a masked examiner. Additionally, 2 pediatric neuro- ophthalmologists graded visual behavior using the 6-level Visual Behavior Scale (VBS). Eye tracking and TAC were performed at baseline and at 1 month. Test–retest reliability of eye tracking and TAC were assessed using the intraclass correlation coefficient (ICC). Eye tracking and TAC visual acuities were correlated with one another and VBS scores using the Spearman correlation coeffi- cient. • RESULTS: Test–retest reliability was excellent for eye tracking measurement of visual acuity (ICC = 0.81, P < .0001). For pediatric CVI, TAC test–retest reliability was fair (ICC = 0.42 |
Dong-Yang Chen; Qi Wang; Ning-Bo Yang; Xiao-Jing Qin; Hang Li; Wen-Peng Hou; Yu-Shen Ding; Wei-Wei Hou; Ya Wang; Fu-Chun Zhou; Chuan-Yue Wang In: Schizophrenia, vol. 9, no. 1, pp. 1–7, 2023. @article{Chen2023b,The study aimed to investigate the cognitive processing of prospective memory (PM) in patients with schizophrenia spectrum disorders (SSDs) by using an eye-tracking paradigm. In addition, the facilitating effects of prosocial intention (the desire to help others) on PM in SSDs were also examined. In phase 1, 26 patients (group1) and 25 healthy controls (HCs) were compared in an eye-tracking PM paradigm in terms of the PM accuracy and eye-tracking indices. In phase 2, 21 more patients (group2) were recruited, and a prosocial intention was introduced in the eye-tracking PM paradigm. Their PM accuracy and eye-tracking indices were compared with those in group1. The PM cue monitoring was indicated by the total fixation counts and fixation time on distractor words. In phase 1, group1 showed lower PM accuracy, fewer fixation counts and less fixation time on distractor words than HCs. In phase 2, group2 (with prosocial intention) performed significantly better than group1 (with typical instruction) on both PM accuracy and fixation time on distractor words. In both groups of SSDs, the PM accuracy was significantly correlated with both the fixation counts and the fixation time of distractor words. After controlling for the cue monitoring indices, the difference in PM accuracy remained significant between group1 and HCs but disappeared between group1 and group2. The cue monitoring deficit contributes to the PM impairment in SSDs. The facilitating effect of prosocial intention disappears after the control of cue monitoring, also indicating its critical role in PM. |
Christoforos Christoforou; Maria Theodorou; Argyro Fella; Timothy C. Papadopoulos RAN-related neural-congruency: A machine learning approach toward the study of the neural underpinnings of naming speed Journal Article In: Frontiers in Psychology, vol. 14, pp. 1–15, 2023. @article{Christoforou2023,Objective: Naming speed, behaviorally measured via the serial Rapid automatized naming (RAN) test, is one of the most examined underlying cognitive factors of reading development and reading difficulties (RD). However, the unconstrained-reading format of serial RAN has made it challenging for traditional EEG analysis methods to extract neural components for studying the neural underpinnings of naming speed. The present study aims to explore a novel approach to isolate neural components during the serial RAN task that are (a) informative of group differences between children with dyslexia (DYS) and chronological age controls (CAC), (b) improve the power of analysis, and (c) are suitable for deciphering the neural underpinnings of naming speed. Methods: We propose a novel machine-learning-based algorithm that extracts spatiotemporal neural components during serial RAN, termed RAN-related neural-congruency components. We demonstrate our approach on EEG and eye-tracking recordings from 60 children (30 DYS and 30 CAC), under phonologically or visually similar, and dissimilar control tasks. Results: Results reveal significant differences in the RAN-related neural-congruency components between DYS and CAC groups in all four conditions. Conclusion: Rapid automatized naming-related neural-congruency components capture the neural activity of cognitive processes associated with naming speed and are informative of group differences between children with dyslexia and typically developing children. Significance: We propose the resulting RAN-related neural-components as a methodological framework to facilitate studying the neural underpinnings of naming speed and their association with reading performance and related difficulties. |
Carmen Julia Coloma; Ernesto Guerra; Zulema De Barbieri; Andrea Helo; Zulema De Barbieri; Andrea Helo; Carmen Julia; Ernesto Guerra; Zulema De Barbieri; Andrea Helo Article comprehension in monolingual Spanish-speaking children with developmental language disorder: A longitudinal eye tracking study Journal Article In: International Journal of Speech-Language Pathology, pp. 1–13, 2023. @article{Coloma2023,Purpose: Article-noun disagreement in spoken language is a marker of children with developmental language disorder (DLD). However, the evidence is less clear regarding article comprehension. This study investigates article comprehension in monolingual Spanish-speaking children with and without DLD. Method: Eye tracking methodology used in a longitudinal experimental design enabled the examination of real time article comprehension. The children at the time 1 were 40 monolingual Spanish-speaking preschoolers (20 with DLD and 20 with typical language development [TLD]). A year later (time 2), 27 of these children (15 with DLD and 12 with TLD) were evaluated. Children listened to simple phrases while inspecting a four object visual context. The article in the phrase agreed in number and gender with only one of the objects. Result: At the time 1, children with DLD did not use articles to identify the correct image, while children with TLD anticipated the correct picture. At the time 2, both groups used the articles' morphological markers, but children with DLD showed a slower and weaker preference for the correct referent compared to their age-matched peers. Conclusion: These findings suggest a later emergence, but a similar developmental trajectory, of article comprehension in children with DLD compared to their peers with TLD. |
Rebekka Schröder; Kristof Keidel; Peter Trautner; Alexander Radbruch; Ulrich Ettinger Neural mechanisms of background and velocity effects in smooth pursuit eye movements Journal Article In: Human Brain Mapping, vol. 44, no. 3, pp. 1–17, 2023. @article{Schroeder2023a,Smooth pursuit eye movements (SPEM) are essential to guide behaviour in complex visual environments. SPEM accuracy is known to be degraded by the presence of a structured visual background and at higher target velocities. The aim of this preregistered study was to investigate the neural mechanisms of these robust behavioural effects. N = 33 participants performed a SPEM task with two background conditions (present and absent) at two target velocities (0.4 and 0.6 Hz). Eye movement and BOLD data were collected simultaneously. Both the presence of a structured background and faster target velocity decreased pursuit gain and increased catch-up saccade rate. Faster targets additionally increased position error. Higher BOLD response with background was found in extensive clusters in visual, parietal, and frontal areas (including the medial frontal eye fields; FEF) partially overlapping with the known SPEM network. Faster targets were associated with higher BOLD response in visual cortex and left lateral FEF. Task-based functional connectivity analyses (psychophysiological interactions; PPI) largely replicated previous results in the basic SPEM network but did not yield additional information regarding the neural underpinnings of the background and velocity effects. The results show that the presentation of visual background stimuli during SPEM induces activity in a widespread visuo-parieto-frontal network including areas contributing to cognitive aspects of oculomotor control such as medial FEF, whereas the response to higher target velocity involves visual and motor areas such as lateral FEF. Therefore, we were able to propose for the first time different functions of the medial and lateral FEF during SPEM. |
Werner Seitz; Artyom Zinchenko; Hermann J. Müller; Thomas Geyer Contextual cueing of visual search reflects the acquisition of an optimal, one-for-all oculomotor scanning strategy Journal Article In: Communications Psychology, vol. 1, no. 1, pp. 1–12, 2023. @article{Seitz2023,Visual search improves when a target is encountered repeatedly at a fixed location within a stable distractor arrangement (spatial context), compared to non-repeated contexts. The standard account attributes this contextual-cueing effect to the acquisition of display-specific long-term memories, which, when activated by the current display, cue attention to the target location. Here we present an alternative, procedural-optimization account, according to which contextual facilitation arises from the acquisition of generic oculomotor scanning strategies, optimized with respect to the entire set of displays, with frequently searched displays accruing greater weight in the optimization process. To decide between these alternatives, we examined measures of the similarity, across time-on-task, of the spatio-temporal sequences of fixations through repeated and non-repeated displays. We found scanpath similarity to increase generally with learning, but more for repeated versus non-repeated displays. This pattern contradicts display-specific guidance, but supports one-for-all scanpath optimization. |
Anaïs Servais; Noémie Préa; Christophe Hurter; Emmanuel J. Barbeau In: Acta Psychologica, vol. 240, pp. 1–13, 2023. @article{Servais2023,It is common to look away while trying to remember specific information, for example during autobiographical memory retrieval, a behavior referred to as gaze aversion. Given the competition between internal and external attention, gaze aversion is assumed to play a role in visual decoupling, i.e., suppressing environmental distractors during internal tasks. This suggests a link between gaze aversion and the attentional switch from the outside world to a temporary internal mental space that takes place during the initial stage of memory retrieval, but this assumption has never been verified so far. We designed a protocol where 33 participants answered 48 autobiographical questions while their eye movements were recorded with an eye-tracker and a camcorder. Results indicated that gaze aversion occurred early (median 1.09 s) and predominantly during the access phase of memory retrieval—i.e., the moment when the attentional switch is assumed to take place. In addition, gaze aversion lasted a relatively long time (on average 6 s), and was notably decoupled from concurrent head movements. These results support a role of gaze aversion in perceptual decoupling. Gaze aversion was also related to higher retrieval effort and was rare during memories which came spontaneously to mind. This suggests that gaze aversion might be required only when cognitive effort is required to switch the attention toward the internal world to help retrieving hard-to-access memories. Compared to eye vergence, another visual decoupling strategy, the association with the attentional switch seemed specific to gaze aversion. Our results provide for the first time several arguments supporting the hypothesis that gaze aversion is related to the attentional switch from the outside world to memory. |
Yijing Shan; Jay A. Edelman The reduction of saccadic inhibition by distractor repetition Journal Article In: Journal of Neurophysiology, vol. 130, no. 3, pp. 619–627, 2023. @article{Shan2023,When visual distractors are presented far from the goal of an impending voluntary saccadic eye movement, saccade execution will occur less frequently about 90 ms after distractor appearance, a phenomenon known as saccadic inhibition. However, it is also known that neural responses in visual and visuomotor areas of the brain will be attenuated if a visual stimulus appears several times in the same location in rapid succession. In particular, such visual adaptation can affect neurons in the mammalian superior colliculus (SC). As the SC is known to be intimately involved in the production of saccadic eye movements, and thus perhaps in saccadic inhibition, we used a memory-guided saccade task to test whether saccadic inhibition in humans would diminish if a distractor appeared several times in quick succession. We found that distractor repetition reduced saccadic inhibition considerably when distractors appeared opposite in space to the goal of the impending saccade. In addition, when three distractors appeared in quick succession but in different, spatially disparate locations, with only the final distractor appearing opposite the saccade goal, saccadic inhibition was reduced by an intermediate level, suggesting that its reduction due to distractor inhibition spatially generalizes. This suggests that distractor suppression can help reduce the impact that suddenly appearing visual stimuli have on purposive eye movement behavior.NEW & NOTEWORTHY This work combines approaches studying saccadic inhibition and visual adaptation to demonstrate that saccadic inhibition is largely eliminated with stimulus repetition. This is likely to be the largest demonstrated effect of visual stimulus context on saccadic inhibition. It also provides evidence for the existence of a mechanism that acts to suppress the effect of frequently appearing visual stimuli on purposive eye movement behavior in dynamic visual environments. |
Tarkeshwar Singh; John-Ross Rizzo; Cédrick Bonnet; Jennifer A. Semrau; Troy M. Herter Enhanced cognitive interference during visuomotor tasks may cause eye–hand dyscoordination Journal Article In: Experimental Brain Research, vol. 241, no. 2, pp. 547–558, 2023. @article{Singh2023,In complex visuomotor tasks, such as cooking, people make many saccades to continuously search for items before and during reaching movements. These tasks require cognitive resources, such as short-term memory and task-switching. Cognitive load may impact limb motor performance by increasing demands on mental processes, but mechanisms remain unclear. The Trail-Making Tests, in which participants sequentially search for and make reaching movements to 25 targets, consist of a simple numeric variant (Trails-A) and a cognitively challenging variant that requires alphanumeric switching (Trails-B). We have previously shown that stroke survivors and age-matched controls make many more saccades in Trails-B, and those increases in saccades are associated with decreases in speed and smoothness of reaching movements. However, it remains unclear how patients with neurological injuries, e.g., stroke, manage progressive increases in cognitive load during visuomotor tasks, such as the Trail-Making Tests. As Trails-B trial progresses, switching between numbers and letters leads to progressive increases in cognitive load. Here, we show that stroke survivors with damage to frontoparietal areas and age-matched controls made more saccades and had longer fixations as they progressed through the 25 alphanumeric targets in Trails-B. Furthermore, when stroke survivors made saccades during reaching movements in Trails-B, their movement speed slowed down significantly. Thus, damage to frontoparietal areas serving cognitive motor functions may cause interference between oculomotor, visual, and limb motor functions, which could lead to significant disruptions in activities of daily living. These findings augment our understanding of the mechanisms that underpin cognitive-motor interference during complex visuomotor tasks. |
Maverick E. Smith; Lester C. Loschky; Heather R. Bailey Eye movements and event segmentation: Eye movements reveal age-related differences in event model updating Journal Article In: Psychology and Aging, pp. 1–8, 2023. @article{Smith2023,People spontaneously segment continuous ongoing actions into sequences of events. Prior research found that gaze similarity and pupil dilation increase at event boundaries and that older adults segmentmore idiosyncratically than do young adults.We used eye tracking to explore age-related differences in gaze similarity (i.e., the extent to which individuals look at the same places at the same time as others) and pupil dilation at event boundaries. Older and young adults watched naturalistic videos of actors performing everyday activities while we tracked their eye movements. Afterward, they segmented the videos into subevents. Replicating prior work, we found that pupil size and gaze similarity increased at event boundaries. Thus, there were fewer individual differences in eye position at boundaries.We also found that young adults had higher gaze similarity than older adults throughout an entire video and at event boundaries. This study is the first to show that age-related differences in how people parse continuous everyday activities into events may be partially explained by individual differences in gaze patterns. Those who segment less normatively may do so because they fixate less normative regions. Results have implications for future interventions designed to improve encoding in older adults. |
Emma J. Solly; Meaghan Clough; Allison M. McKendrick; Owen B. White; Joanne Fielding Eye movement characteristics are not significantly influenced by psychiatric comorbidities in people with visual snow syndrome Journal Article In: Brain Research, vol. 1804, pp. 1–5, 2023. @article{Solly2023,Visual snow syndrome (VSS) is a neurological disorder primarily affecting the processing of visual information. Using ocular motor (OM) tasks, we previously demonstrated that participants with VSS exhibit altered saccade profiles consistent with visual attention impairments. We subsequently proposed that OM assessments may provide an objective measure of dysfunction in these individuals. However, VSS participants also frequently report significant psychiatric symptoms. Given that that these symptoms have been shown previously to influence performance on OM tasks, the objective of this study was to investigate whether psychiatric symptoms (specifically: depression, anxiety, fatigue, sleep difficulties, and depersonalization) influence the OM metrics found to differ in VSS. Sixty-one VSS participants completed a battery of four OM tasks and a series of online questionnaires assessing psychiatric symptomology. We revealed no significant relationship between psychiatric symptoms and OM metrics on any of the tasks, demonstrating that in participants with VSS, differences in OM behaviour are a feature of the disorder. This supports the utility of OM assessment in characterising deficit in VSS, whether supporting a diagnosis or monitoring future treatment efficacy. |
Sangkyu Son; Joonsik Moon; Yee-Joon Kim; Min-Suk Kang; Joonyeol Lee Frontal-to-visual information flow explains predictive motion tracking Journal Article In: NeuroImage, vol. 269, pp. 1–11, 2023. @article{Son2023,Predictive tracking demonstrates our ability to maintain a line of vision on moving objects even when they temporarily disappear. Models of smooth pursuit eye movements posit that our brain achieves this ability by directly streamlining motor programming from continuously updated sensory motion information. To test this hypothesis, we obtained sensory motion representation from multivariate electroencephalogram activity while human participants covertly tracked a temporarily occluded moving stimulus with their eyes remaining stationary at the fixation point. The sensory motion representation of the occluded target evolves to its maximum strength at the expected timing of reappearance, suggesting a timely modulation of the internal model of the visual target. We further characterize the spatiotemporal dynamics of the task-relevant motion information by computing the phase gradients of slow oscillations. We discovered a predominant posterior-to-anterior phase gradient immediately after stimulus occlusion; however, at the expected timing of reappearance, the axis reverses the gradient, becoming anterior-to-posterior. The behavioral bias of smooth pursuit eye movements, which is a signature of the predictive process of the pursuit, was correlated with the posterior division of the gradient. These results suggest that the sensory motion area modulated by the prediction signal is involved in updating motor programming. |
David Souto; Jennifer Sudkamp; Kyle Nacilla; Mateusz Bocian Tuning in to a hip-hop beat: Pursuit eye movements reveal processing of biological motion Journal Article In: Human Movement Science, vol. 91, pp. 1–12, 2023. @article{Souto2023,Smooth pursuit eye movements are mainly driven by motion signals to achieve their goal of reducing retinal motion blur. However, they can also show anticipation of predictable movement patterns. Oculomotor predictions may rely on an internal model of the target kinematics. Most investigations on the nature of those predictions have concentrated on simple stimuli, such as a decontextualized dot. However, biological motion is one of the most important visual stimuli in regulating human interaction and its perception involves integration of form and motion across time and space. Therefore, we asked whether there is a specific contribution of an internal model of biological motion in driving pursuit eye movements. Unlike previous contributions, we exploited the cyclical nature of walking to measure eye movement's ability to track the velocity oscillations of the hip of point-light walkers. We quantified the quality of tracking by cross-correlating pursuit and hip velocity oscillations. We found a robust correlation between signals, even along the horizontal dimension, where changes in velocity during the stepping cycle are very subtle. The inversion of the walker and the presentation of the hip-dot without context incurred the same additional phase lag along the horizontal dimension. These findings support the view that information beyond the hip-dot contributes to the prediction of hip kinematics that controls pursuit. We also found a smaller phase lag in inverted walkers for pursuit along the vertical dimension compared to upright walkers, indicating that inversion does not simply reduce prediction. We suggest that pursuit eye movements reflect the visual processing of biological motion and as such could provide an implicit measure of higher-level visual function. |
Maximilian Stefani; Marian Sauter Relative contributions of oculomotor capture and disengagement to distractor-related dwell times in visual search Journal Article In: Scientific Reports, vol. 13, no. 1, pp. 1–10, 2023. @article{Stefani2023,In visual search, attention is reliably captured by salient distractors and must be actively disengaged from them to reach the target. In such attentional capture paradigms, dwell time is measured on distractors that appear in the periphery (e.g., on a random location on a circle). Distractor-related dwell time is typically thought to be largely due to stimulus-driven processes related to oculomotor capture dynamics. However, the extent to which oculomotor capture and oculomotor disengagement contribute to distractor dwell time has not been known because standard attentional capture paradigms cannot decouple these processes. In the present study, we used a novel paradigm combining classical attentional capture trials and delayed disengagement trials. We measured eye movements to dissociate the capture and disengagement mechanisms underlying distractor dwell time. We found that only two-thirds of distractor dwell time (~ 52 ms) can be explained by oculomotor capture, while one-third is explained by oculomotor disengagement (~ 18 ms), which has been neglected or underestimated in previous studies. Thus, oculomotor disengagement (goal-directed) processes play a more significant role in distractor dwell times than previously thought. |
Moritz Stolte; Leon Kraus; Ulrich Ansorge Visual attentional guidance during smooth pursuit eye movements: Distractor interference is independent of distractor-target similarity Journal Article In: Psychophysiology, vol. 60, no. 12, pp. 1–11, 2023. @article{Stolte2023,In the current study, we used abrupt-onset distractors similar and dissimilar in luminance to the target of a smooth pursuit eye-movement to test if abrupt-onset distractors capture attention in a top-down or bottom-up fashion while the eyes track a moving object. Abrupt onset distractors were presented at different positions relative to the current position of a pursuit target during the closed-loop phase of smooth pursuit. Across experiments, we varied the duration of the distractors, their motion direction, and task-relevance. We found that abrupt-onset distractors decreased the gain of horizontally directed smooth-pursuit eye-movements. This effect, however, was independent of the similarity in luminance between distractor and target. In addition, distracting effects on horizontal gain were the same, regardless of the exact duration and position of the distractors, suggesting that capture was relatively unspecific and short-lived (Experiments 1 and 2). This was different with distractors moving in a vertical direction, perpendicular to the horizontally moving target. In line with past findings, these distractors caused suppression of vertical gain (Experiment 3). Finally, making distractors task-relevant by asking observers to report distractor positions increased the pursuit gain effect of the distractors. This effect was also independent of target-distractor similarity (Experiment 4). In conclusion, the results suggest that a strong location signal exerted by the pursuit targets led to very brief and largely location-unspecific interference through the abrupt onsets and that this interference was bottom-up, implying that the control of smooth pursuit was independent of other target features besides its motion signal. |
Georgia F. Symons; William T. O'Brien; Larry Abel; Zhibin Chen; Daniel M. Costello; Terence J. O'Brien; Scott Kolbe; Joanne Fielding; Sandy R. Shultz; Meaghan Clough; William T. O'Brien; Larry Abel; Zhibin Chen; Daniel M. Costello; Terence J. O'brien; Scott Kolbe; Joanne Fielding; Sandy R. Shultz; Meaghan Clough Monitoring the acute and subacute recovery of cognitive ocular motor changes after a sports-related concussion Journal Article In: Cerebral Cortex, vol. 33, no. 9, pp. 5276–5288, 2023. @article{Symons2023,Identifying when recovery from a sports-related concussion (SRC) has occurred remains a challenge in clinical practice. This study investigated the utility of ocular motor (OM) assessment to monitor recovery post-SRC between sexes and compared to common clinical measures. From 139 preseason baseline assessments (i.e. before they sustained an SRC), 18 (12 males, 6 females) consequent SRCs were sustained and the longitudinal follow-ups were collected at 2, 6, and 13 days post-SRC. Participants completed visually guided, antisaccade (AS), and memory-guided saccade tasks requiring a saccade toward, away from, and to a remembered target, respectively. Changes in latency (processing speed), visual-spatial accuracy, and errors were measured. Clinical measures included The Sports Concussion Assessment Tool, King-Devick test, Stroop task, and Digit span. AS latency was significantly longer at 2 days and returned to baseline by 13-days post-SRC in females only (P < 0.001). Symptom numbers recovered from 2 to 6 days and 13 days (P < 0.05). Persistently poorer AS visual-spatial accuracy was identified at 2, 6 and 13 days post-SRC (P < 0.05) in both males and females but with differing trajectories. Clinical measures demonstrated consistent improvement reminiscent of practice effects. OM saccade assessment may have improved utility in tracking recovery compared to conventional measures and between sexes. |
Noam Tal-Perry; Shlomit Yuval-Greenberg Sequential effect and temporal orienting in prestimulus oculomotor inhibition Journal Article In: Journal of Vision, vol. 23, no. 14, pp. 1–13, 2023. @article{TalPerry2023,When faced with unfamiliar circumstances, we often turn to our past experiences with similar situations to shape our expectations. This results in the well-established sequential effect, in which previous trials influence the expectations of the current trial. Studies have revealed that, in addition to the classical behavioral metrics, the inhibition of eye movement could be used as a biomarker to study temporal expectations. This prestimulus oculomotor inhibition is found a few hundred milliseconds prior to predictable events, with a stronger inhibition for predictable than unpredictable events. The phenomenon has been found to occur in various temporal structures, such as rhythms, cue-association, and conditional probability, yet it is still unknown whether it reflects local sequential information of the previous trial. To explore this, we examined the relationship between the sequential effect and the prestimulus oculomotor inhibition. Our results (N = 40) revealed that inhibition was weaker when the previous trial was longer than the current trial, in line with findings of behavioral metrics. These findings indicate that the prestimulus oculomotor inhibition covaries with expectation based on local sequential information, demonstrating the tight connection between this phenomenon and expectation and providing a novel measurement for studying sequential effects in temporal expectation. |
Pin Kwang Tan; Cheng Tang; Roger Herikstad; Arunika Pillay; Camilo Libedinsky Distinct lateral prefrontal regions are organized in an anterior-posterior functional gradient Journal Article In: Journal of Neuroscience, vol. 43, no. 38, pp. 6564–6572, 2023. @article{Tan2023a,The dorsolateral prefrontal cortex (dlPFC) is composed of multiple anatomically-defined regions involved in higher-order cognitive processes, including working memory and selective attention. It is organized in an anterior-posterior global gradient where posterior regions track changes in the environment while anterior regions support abstract neural representations. However, it remains unknown if such a global gradient results from a smooth gradient that spans regions, or an emergent property arising from functionally distinct regions, i.e. an areal gradient. Here, we recorded single-neurons in the dlPFC of non-human primates trained to perform a memory-guided saccade task with an interfering distractor, and analyzed their physiological properties along the anterior-posterior axis. We found that these physiological properties were best described by an areal gradient. Further, population analyses revealed that there is a distributed representation of spatial information across the dlPFC. Our results validate the functional boundaries between anatomically-defined dlPFC regions and highlight the distributed nature of computations underlying working memory across the dlPFC. Significance Statement Activity of frontal lobe regions is known to possess an anterior-posterior functional gradient. However, it is not known whether this gradient is the result of individual brain regions organized in a gradient (like a staircase), or a smooth gradient that spans regions (like a slide). Analysis of physiological properties of individual neurons in the primate frontal regions suggest that individual regions are organized as a gradient, rather than a smooth gradient. At the population level, working memory was more prominent in posterior regions, even though it was also present in anterior regions. This is consistent with the functional segregation of brain regions that is also observed in other systems (i.e. the visual system). |
Junru Wu; Min Li; Wenbo Ma; Zhihao Zhang; Mingsha Zhang; Xuemei Li In: Gerontology, vol. 69, no. 3, pp. 321–335, 2023. @article{Wu2023d,Background: Among the elderly, dementia is a common and disabling disorder with primary manifestations of cognitive impairments. Diagnosis and intervention in its early stages is the key to effective treatment. Nowadays, the test of cognitive function relies mainly on neuropsychological tests, such as the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). However, they have noticeable shortcomings, e.g., the biases of subjective judgments from physicians and the cost of the labor of these well-trained physicians. Thus, advanced and objective methods are urgently needed to evaluate cognitive functions. Methods: We developed a cognitive assessment system through measuring the saccadic eye movements in three tasks. The cognitive functions were evaluated by both our system and the neuropsychological tests in 310 subjects, and the evaluating results were directly compared. Results: In general, most saccadic parameters correlate well with the MMSE and MoCA scores. Moreover, some subjects with high MMSE and MoCA scores have high error rates in performing these three saccadic tasks due to various errors. The primary error types vary among tasks, indicating that different tasks assess certain specific brain functions preferentially. Thus, to improve the accuracy of evaluation through saccadic tasks, we built a weighted model to combine the saccadic parameters of the three saccadic tasks, and our model showed a good diagnosis performance in detecting patients with cognitive impairment. Conclusion: The comprehensive analysis of saccadic parameters in multiple tasks could be a reliable, objective, and sensitive method to evaluate cognitive function and thus to help diagnose cognitive impairments. |
Ji Su Yeon; Ha Na Jung; Jae-Young Kim; Kyong In Jung; Hae Young Lopilly Park; Chan Kee Park; Hyo Won Kim; Man Soo Kim; Yong Chan Kim Deviated saccadic trajectory as a biometric signature of glaucoma Journal Article In: Translational Vision Science & Technology, vol. 12, no. 7, pp. 1–12, 2023. @article{Yeon2023,Purpose: To investigate whether the trajectories of saccadic eye movements (SEMs) significantly differ between glaucoma patients and controls. Methods: SEMs were recorded by video-based infrared oculography in 53 patients with glaucoma and 41 age-matched controls. Participants were asked to bilaterally view 24°-horizontal, 14°-vertical, and 20°-diagonal eccentric Goldmann III-sized stimuli. SEMs were evaluated with respect to the saccadic reaction time (SRT), the mean velocity, amplitude, and two novel measures: departure angle (DA) and arrival angle (AA). These parameters were compared between the groups and the associations of SEM parameters with glaucoma parameters and integrated visual field defects were investigated. Results: Glaucoma patients exhibited increased mean SRT, DA, and AA values compared with controls for 14°-vertical visual targets (P = 0.05, P < 0.01, and P < 0.01, respectively). The SRT, DA, and AA were significantly associated with the mean and pattern standard deviations of perimetry and with the mean RNFL thickness by OCT (all P < 0.001). Glaucoma was associated with the AA (P = 0.05) and both the SRT (P = 0.01) and DA (P = 0.04) were associated with integrated visual field defects. Conclusions: The saccadic trajectories of glaucoma patients depart in an erroneous path and compensate the disparity by deviating the trajectory at arrival. Translational Relevance: The initial deviation that we observed (despite continuous exposure to the stimulus) suggests the disoriented spatial perception of glaucoma patients which may be relevant to difficulties encountered daily. |
Dan Zhang; Lihua Xu; Yuou Xie; Xiaochen Tang; Yegang Hu; Xu Liu; Guisen Wu; Zhenying Qian; Yingying Tang; Zhi Liu; Tao Chen; HaiChun Liu; Tianhong Zhang; Jijun Wang Eye movement indices as predictors of conversion to psychosis in individuals at clinical high risk Journal Article In: European Archives of Psychiatry and Clinical Neuroscience, vol. 273, no. 3, pp. 553–563, 2023. @article{Zhang2023i,Eye movement abnormalities have been established as an “endophenotype” of schizophrenia. However, less is known about the possibility of these abnormalities as biomarkers for psychosis conversion among clinical high risk (CHR) populations. In the present study, 108 CHR individuals and 70 healthy controls (HC) underwent clinical assessments and eye-tracking tests, comprising fixation stability and free-viewing tasks. According to three-year follow-up outcomes, CHR participants were further stratified into CHR-converter (CHR-C; n = 21) and CHR-nonconverter (CHR-NC; n = 87) subgroups. Prediction models were constructed using Cox regression and logistic regression. The CHR-C group showed more saccades of the fixation stability test (no distractor) and a reduced saccade amplitude of the free-viewing test than HC. Moreover, the CHR-NC group exhibited excessive saccades and an increased saccade amplitude of the fixation stability test (no distractor; with distractor) compared with HC. Furthermore, two indices could effectively discriminate CHR-C from CHR-NC with an area under the receiver-operating characteristic (ROC) curve of 0.80, including the saccade number of the fixation stability test (no distractor) and the saccade amplitude of the free-viewing test. Combined with negative symptom scores of the Scale of Prodromal Symptoms, the area was 0.81. These findings support that eye movement alterations might emerge before the onset of clinically overt psychosis and could assist in predicting psychosis transition among CHR populations. |