EyeLink fMRI / MEG Publications
All EyeLink fMRI and MEG research publications (with concurrent eye tracking) up until 2023 (with some early 2024s) are listed below by year. You can search the publications using keywords such as Visual Cortex, Neural Plasticity, MEG, etc. You can also search for individual author names. If we missed any EyeLink fMRI or MEG articles, please email us!
2022 |
Sinem B. Beylergil; Camilla Kilbane; Aasef G. Shaikh; Fatema F. Ghasia Eye movements in Parkinson's disease during visual search Journal Article In: Journal of the Neurological Sciences, vol. 440, pp. 1–16, 2022. @article{Beylergil2022, Visual spatial dysfunction is not uncommon in Parkinson's disease. We hypothesized that visual search behavior is impaired in Parkinson's disease and the deficits correlate with changes in the amplitudes and frequency of fixational and non-fixational rapid eye movements. We measured eye movements, the horizontal and vertical angular position vectors of the right and left eye using high-resolution video oculography, in the Parkinsonian cohort who viewed a blank scene and pictures with real-life scene. Latter was associated with a task of searching an object hidden in a clutter, either at an expected or an unexpected location. Parkinsonian cohort took longer initial time to reach the region of interest. The ultimate response time was comparable in both Parkinson's disease and their healthy peers. The fixation duration was comparable in two cohorts but there was a trend wise decline for the ones located at unexpected locations. Parkinson's disease participants made more fixational saccades with significantly larger amplitude and less non-fixational saccades with significantly smaller amplitude during blank scene viewing. However, overall scanned area of the blank scene was not affected in Parkinson's disease. The Parkinson's disease participants made less non-fixational saccades with amplitudes comparable to healthy control during the visual search of a target object. Fixational saccades during visual search were larger in Parkinson's disease particularly when target was placed at an unexpected location, but the frequency was unchanged. |
Sinem Balta Beylergil; Jordan Murray; Angela M. Noecker; Palak Gupta; Camilla Kilbane; Cameron C. McIntyre; Fatema F. Ghasia; Aasef G. Shaikh Temporal patterns of spontaneous fixational eye movements: The influence of basal ganglia Journal Article In: Journal of Neuro-Ophthalmology, vol. 42, no. 1, pp. 45–55, 2022. @article{Beylergil2022a, Background:Spontaneity is a unique feature of the nervous system. One of the fundamentally critical and recognized forms of spontaneous motor activity is witnessed in the visuomotor system. Microsaccades, the miniature spontaneous eye movements, are critical for the visual perception. We hypothesized that microsaccades follow specific temporal patterns that are modulated by the basal ganglia output.Methods:We used high-resolution video-oculography to capture microsaccades in 48 subjects (31 healthy and 17 with Parkinson's disease) when subjects were asked to hold their gaze on a straight-ahead target projected on white background. We analyzed spontaneous discharge patterns of microsaccades.Results:The first analysis considering coefficient of variation in intersaccadic interval distribution demonstrated that microsaccades in Parkinson's disease are more dispersed than the control group. The second analysis scrutinized microsaccades' temporal variability and revealed 3 distinct occurrence patterns: regular rhythmic, clustered, and randomly occurring following a Poisson-like process. The regular pattern was relatively more common in Parkinson's disease. Subthalamic DBS modulated this temporal pattern. The amount of change in the temporal variability depended on the DBS-induced volume of tissue activation and its overlap with the subthalamic nucleus. The third analysis determined the autocorrelations of microsaccades within 2-second time windows. We found that Parkinson's disease altered local temporal organization in microsaccade generation, and DBS had a modulatory effect.Conclusion:The microsaccades occur in 3 temporal patterns. The basal ganglia are one of the modulators of the microsaccade spontaneity. |
Isha Bhutada; Peggy Skelly; Jonathan Jacobs; Jordan Murray; Aasef G. Shaikh; Fatema F. Ghasia Reading difficulties in amblyopia: Consequence of visual sensory and oculomotor dysfunction Journal Article In: Journal of the Neurological Sciences, vol. 442, pp. 1–13, 2022. @article{Bhutada2022, Introduction: Reading is a vision-reliant task, requiring sequential eye movements. Binocularly discordant input results in visual sensory and oculomotor dysfunction in amblyopia, which may contribute to reading difficulties. This study aims to determine the contributions of fixation eye movement (FEM) abnormalities, clinical type and severity of amblyopia to reading performance under binocular and monocular viewing conditions. Methods: Twenty-three amblyopic patients and nine healthy controls were recruited. Eye movements elicited during fixation and reading of preselected passages were collected for each subject using infrared video- oculography. Subjects were classified as having no nystagmus (n = 9), fusion maldevelopment nystagmus (FMN |
Carola Bloch; Ralf Tepest; Mathis Jording; Kai Vogeley; Christine M. Falter-Wagner Intrapersonal synchrony analysis reveals a weaker temporal coherence between gaze and gestures in adults with autism spectrum disorder Journal Article In: Scientific Reports, vol. 12, no. 1, pp. 1–12, 2022. @article{Bloch2022, The temporal encoding of nonverbal signals within individuals, referred to as intrapersonal synchrony (IaPS), is an implicit process and essential feature of human communication. Based on existing evidence, IaPS is thought to be a marker of nonverbal behavior characteristics in autism spectrum disorders (ASD), but there is a lack of empirical evidence. The aim of this study was to quantify IaPS in adults during an experimentally controlled real-life interaction task. A sample of adults with a confirmed ASD diagnosis and a matched sample of typically-developed adults were tested (N = 48). Participants were required to indicate the appearance of a target invisible to their interaction partner nonverbally through gaze and pointing gestures. Special eye-tracking software allowed automated extraction of temporal delays between nonverbal signals and their intrapersonal variability with millisecond temporal resolution as indices for IaPS. Likelihood ratio tests of multilevel models showed enlarged delays between nonverbal signals in ASD. Larger delays were associated with greater intrapersonal variability in delays. The results provide a quantitative constraint on nonverbal temporality in typically-developed adults and suggest weaker temporal coherence between nonverbal signals in adults with ASD. The results provide a potential diagnostic marker and inspire predictive coding theories about the role of IaPS in interpersonal synchronization processes. |
Ariel Boyle; Aaron Johnson; Mark Ellenbogen Intranasal oxytocin alters attention to emotional facial expressions, particularly for males and those with depressive symptoms Journal Article In: Psychoneuroendocrinology, vol. 142, pp. 1–13, 2022. @article{Boyle2022, Intranasal oxytocin (OT) can enhance emotion recognition, perhaps by promoting increased attention to social cues. Some studies indicate that individuals with difficulties processing social information, including those with psychopathology, show more pronounced effects in response to OT. As such, there is interest in the potential therapeutic use of OT in populations with deficits in social cognition. The present study examined the effects of intranasal OT on the processing of facial features and selective attention to emotional facial expressions, as well as whether individual differences in depressive symptom severity predict sensitivity to intranasal OT. In a double-blind placebo-controlled within-subject design, eye tracking was used to measure attention to facial features in an emotional expression appraisal task, and attention to emotional expressions in a free-viewing task with a quadrant of multiple faces. OT facilitated the processing of positive cues, enhancing the maintenance of attention to the mouth region of happy faces and to happy faces within a quadrant, with similar effect sizes, despite the latter effect not being statistically significant. Further, persons with depressive symptoms, and particularly males, were sensitive to OT's effects. For males only, OT, relative to placebo, increased attentional focus to the mouth region of all faces. Individuals with depressive symptoms showed less attentional focus on angry (males only) and sad facial expressions, and more attention to happy faces (particularly for males). Results indicate increased sensitivity to OT in males and persons at risk for depression, with OT administration promoting a positive bias in selective attention to social stimuli. |
Sven Braeutigam; Jessica Clare Scaife; Tipu Aziz; Rebecca J. Park A longitudinal magnetoencephalographic study of the effects of deep brain stimulation on neuronal dynamics in severe anorexia nervosa Journal Article In: Frontiers in Behavioral Neuroscience, vol. 16, pp. 1–12, 2022. @article{Braeutigam2022, Anorexia Nervosa (AN) is a debilitating psychiatric disorder characterized by the relentless pursuit of thinness, leading to severe emaciation. Magnetoencephalography (MEG)was used to record the neuronal response in seven patients with treatment-resistant AN while completing a disorder-relevant food wanting task. The patients underwent a 15-month protocol, where MEG scans were conducted pre-operatively, post-operatively prior to deep brain stimulation (DBS) switch on, twice during a blind on/off month and at protocol end. Electrodes were implanted bilaterally into the nucleus accumbens with stimulation at the anterior limb of the internal capsule using rechargeable implantable pulse generators. Three patients met criteria as responders at 12 months of stimulation, showing reductions of eating disorder psychopathology of over 35%. An increase in alpha power, as well as evoked power at latencies typically associated with visual processing, working memory, and contextual integration was observed in ON compared to OFF sessions across all seven patients. Moreover, an increase in evoked power at P600-like latencies as well as an increase in γ-band phase-locking over anterior-to-posterior regions were observed for high- compared to low-calorie food image only in ON sessions. These findings indicate that DBS modulates neuronal process in regions far outside the stimulation target site and at latencies possibly reflecting task specific processing, thereby providing further evidence that deep brain stimulation can play a role in the treatment of otherwise intractable psychiatric disorders. |
Jana Bretthauer; Daniela Canu; Ulf Thiemann; Christian Fleischhaker; Heike Brauner; Katharina Müller; Nikolaos Smyrnis; Monica Biscaldi; Stephan Bender; Christoph Klein Attention for emotion—How young adults with neurodevelopmental disorders look at facial expressions of affect Journal Article In: Frontiers in Psychiatry, vol. 13, pp. 1–17, 2022. @article{Bretthauer2022, While Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD) and Schizophrenia (SCZ) differ in many clinically relevant features such as symptomatology and course, they may also share genetic underpinnings, affective problems, deviancies in social interactions, and are all characterized by some kind of cognitive impairment. This situation calls for a joint investigation of the specifics of cognitive (dys-)functions of the three disorders. Such endeavor should focus, among other domains, on the intersection of processing cognitive, affective and social information that is crucial in effective real-life interactions and can be accomplished when attentional preferences for human facial expressions of emotions is studied. To that end, attention to facial expressions of basic emotions was examined in young adults with ASD, ADHD, or SCZ in the present study. The three clinical groups were compared with an age-matched group of typically-developing participants (TD) during the free contemplation of five different facial emotions presented simultaneously, by varying identities, through the registration of eye movements. We showed, that dwell times and fixation counts differed for the different emotions in TD and in a highly similar way in ADHD. Patients with ASD differed from TD by showing a stronger differentiation between emotions and partially different attentional preferences. In contrast, the SCZ group showed an overall more restricted scanning behavior and a lack of differentiation between emotions. The ADHD group, showed an emotion-specific gazing pattern that was highly similar to that of controls. Thus, by analyzing eye movements, we were able to differentiate three different viewing patterns that allowed us to distinguish between the three clinical groups. This outcome suggests that attention for emotion may not tap into common pathophysiological processes and argues for a multi-dimensional approach to the grouping of disorders with neurodevelopmental etiology. |
Amanda Fernandez; Leanne Quigley; Keith Dobson; Christopher Sears Coherence of attention and memory biases in currently and previously depressed women Journal Article In: Cognition and Emotion, pp. 1–16, 2022. @article{Fernandez2022, Previous research has found that depression is characterised by biased processing of emotional information. Although most studies have examined cognitive biases in isolation, simultaneous examination of multiple biases is required to understand how they may interact and influence one another to produce depression vulnerability. In this study, the attention and memory biases of currently depressed, previously depressed, and never depressed women were examined using the same stimuli and a unified methodology. Participants viewed negative, positive, and neutral words while their eye gaze was tracked and recorded. After a distraction task, participants completed an incidental recognition test that included words from the eye-tracking task and new words. The results supported the hypothesised mediation model for positive words: currently depressed women had a reduced attention bias for positive words and, in turn, had poorer memory for positive words relative to never depressed women. Previously depressed women, however, showed a lack of coherence between attention and memory biases for positive words. The groups did not differ in their attention or memory biases for negative words. The findings provide novel evidence in support of a causal link between the absence of protective attention and memory biases for positive information in clinical depression. |
Julia Fietz; Dorothee Pöhlchen; Florian P. Binder; Michael Czisch; Philipp G. Sämann; Victor I. Spoormaker Pupillometry tracks cognitive load and salience network activity in a working memory functional magnetic resonance imaging task Journal Article In: Human Brain Mapping, vol. 43, no. 2, pp. 665–680, 2022. @article{Fietz2022, The diameter of the human pupil tracks working memory processing and is associated with activity in the frontoparietal network. At the same time, recent neuroimaging research has linked human pupil fluctuations to activity in the salience network. In this combined functional magnetic resonance imaging (fMRI)/pupillometry study, we recorded the pupil size of healthy human participants while they performed a blockwise organized working memory task (N-back) inside an MRI scanner in order to monitor the pupil fluctuations associated neural activity during working memory processing. We first confirmed that mean pupil size closely followed working memory load. Combining this with fMRI data, we focused on blood oxygen level dependent (BOLD) correlates of mean pupil size modeled onto the task blocks as a parametric modulation. Interrogating this modulated task regressor, we were able to retrieve the frontoparietal network. Next, to fully exploit the within-block dynamics, we divided the blocks into 1 s time bins and filled these with corresponding pupil change values (first-order derivative of pupil size). We found that pupil change within N-back blocks was positively correlated with BOLD amplitudes in the areas of the salience network (namely bilateral insula, and anterior cingulate cortex). Taken together, fMRI with simultaneous measurement of pupil parameters constitutes a valuable tool to dissect working memory subprocesses related to both working memory load and salience of the presented stimuli. |
Cecilia E. García Cena; David Gómez-Andrés; Irene Pulido-Valdeolivas; Victoria Galán Sánchez-Seco; Angela Domingo-Santos; Sara Moreno-García; Julián Benito-León Toward an automatic assessment of cognitive dysfunction in relapsing–remitting multiple sclerosis patients using eye movement analysis Journal Article In: Sensors, vol. 22, pp. 1–18, 2022. @article{GarciaCena2022, Despite the importance of cognitive function in multiple sclerosis, it is poorly represented in the Expanded Disability Status Scale (EDSS), the commonly used clinical measure to assess disability, suggesting that an analysis of eye movement, which is generated by an extensive and well-coordinated functional network that is engaged in cognitive function, could have the potential to extend and complement this more conventional measure. We aimed to measure the eye movement of a case series of MS patients with relapsing–remitting MS to assess their cognitive status using a conventional gaze tracker. A total of 41 relapsing–remitting MS patients and 43 age-matched healthy controls were recruited for this study. Overall, we could not find a clear common pattern in the eye motor abnormalities. Vertical eye movement was more impaired in MS patients than horizontal movement. Increased latencies were found in the prosaccades and reflexive saccades of antisaccade tests. The smooth pursuit was impaired with more corrections (backup and catchup movements, p<0.01). No correlation was found between eye movement variables and EDSS or disease duration. Despite significant alterations in the behavior of the eye movements in MS patients, which are compatible with altered cognitive status, there is no common pattern of these alterations. We interpret this as a consequence of the patchy, heterogeneous distribution of white matter involvement in MS that provokes multiple combinations of impairment at different points in the different networks involved in eye motor control. Further studies are therefore required. |
Nora Geiser; Brigitte Charlotte Kaufmann; Henrik Rühe; Noortje Maaijwee; Tobias Nef; Dario Cazzoli; Thomas Nyffeler Visual neglect after PICA stroke—A case study Journal Article In: Brain Sciences, vol. 12, pp. 1–10, 2022. @article{Geiser2022, After cerebellar stroke, cognition can be impaired, as described within the framework of the so-called Cerebellar Cognitive Affective Syndrome (CCAS). However, it remains unclear whether visual neglect can also be part of CCAS. We describe the case of a patient with a subacute cerebellar stroke after thrombosis of the left posterior inferior cerebellar artery (PICA), who showed a left-sided visual neglect, indicating that the cerebellum also has a modulatory function on visual attention. The neglect, however, was mild and only detectable when using the sensitive neuro-psychological Five-Point Test as well as video-oculography assessment, yet remained unnoticed when evaluated with common neglect-specific paper-pencil tests. Three weeks later, follow-up assessments revealed an amelioration of neglect symptoms. Therefore, these findings suggest that visual neglect may be a part of CCAS, but that the choice of neglect assessments and the time delay since stroke onset may be crucial. Although the exact underlying pathophysiological mechanisms remain unclear, we propose cerebellar–cerebral diaschisis as a possible explanation of why neglect can occur on the ipsilateral side. Further research applying sensitive assessment tools at different post-stroke stages is needed to investigate the incidence, lesion correlates, and pathophysiology of neglect after cerebellar lesions. |
Emma Gowen; Ellen Poliakoff; Hayley Shepherd; Waltraud Stadler Measuring the prediction of observed actions using an occlusion paradigm: Comparing autistic and non-autistic adults Journal Article In: Autism Research, vol. 15, pp. 1636–1648, 2022. @article{Gowen2022, Action prediction involves observing and predicting the actions of others and plays an important role in social cognition and interacting with others. It is thought to use simulation, whereby the observers use their own motor system to predict the observed actions. As individuals diagnosed with autism are characterized by difficulties understanding the actions of others and motor coordination issues, it is possible that action prediction ability is altered in this population. This study compared action prediction ability between 20 autistic and 22 non-autistic adults using an occlusion paradigm. Participants watched different videos of a female actor carrying out everyday actions. During each video, the action was transiently occluded by a gray rectangle for 1000 ms. During occlusions, the video was allowed to continue as normal or was moved forward (i.e., appearing to continue too far ahead) or moved backwards (i.e., appearing to continue too far behind). Participants were asked to indicate after each occlusion whether the action continued with the correct timing or was too far ahead/behind. Autistic individuals were less accurate than non-autistic individuals, particularly when the video was too far behind. A trend analysis suggested that autistic participants were more likely to judge too far behind occlusions as being in time. These preliminary results suggest that prediction ability may be altered in autistic adults, potentially due to slower simulation or a delayed onset of these processes. Lay Summary: When we observe other people performing everyday actions, we use their movements to help us understand and predict what they are doing. In this study, we found that autistic compared to non-autistic adults were slightly less accurate at predicting other people's actions. These findings help to unpick the different ways that social understanding is affected in autism. |
Junyi Zhou; Lulu Wang Differences in the effects of reading and aerobic exercise interventions on inhibitory control of college students with mobile phone addiction Journal Article In: Frontiers in Psychiatry, vol. 13, pp. 1–9, 2022. @article{Zhou2022c, Although many previous studies have shown that short-time moderate-intensity aerobic exercise can improve one's inhibitory control, some researchers suggested that its effect on inhibitory control is small. Meanwhile, some studies have shown that reading has a positive effect on inhibitory control. Since many studies examining the effect of exercise on inhibitory control used reading as a filler task, it is important to compare their effects. The present study used the antisaccade task as a tool to examine the differences in the effects of aerobic exercise and reading on inhibitory control of college students with mobile phone addiction. Thirty healthy college students with mobile phone addiction (range: 17–20 years, mean: 19.2 years) took part in the experiment. Participants were randomly assigned to an aerobic exercise group and a reading group. For the aerobic exercise group, participants were asked to perform moderate-intensity aerobic exercise for 15 min. For the reading group, participants were asked to sit quietly and read articles from newspapers for 15 min. Each participant's inhibitory control was examined pre- and post-intervention using the antisaccade task. In the antisaccade task, they have to direct their gaze toward the mirror image location of the target appearing parafoveally as quickly and as accurately as possible. The results showed significant main effects of Time (pre-test vs. post-test) on antisaccade latency and error rate. More importantly, a significant interaction of Time (pre-test vs. post-test) and Group (aerobic exercise vs. reading) was found on antisaccade latency. Specifically, the antisaccade latencies in the post-test were significantly shorter than those in the pre-test for the reading group, but the antisaccade latencies in the post-test and pre-test were comparable for the aerobic exercise group. The results of the present study imply that although both exercise and reading have effects on inhibitory control of college students with mobile phone addiction, the effect of reading may be somehow superior to exercise. Moreover, the current results also imply that researchers should be cautious when using reading as a filler task in future studies regarding the effect of aerobic exercise. The limitations of the present study were discussed. |
Chen Xing; Yajuan Zhang; Hongliang Lu; Xia Zhu; Danmin Miao Trait anxiety affects attentional bias to emotional stimuli across time: A growth curve analysis Journal Article In: Frontiers in Neuroscience, vol. 16, pp. 1–22, 2022. @article{Xing2022, Many studies have illustrated the close relationship between anxiety disorders and attentional functioning, but the relationship between trait anxiety and attentional bias remains controversial. This study examines the effect of trait anxiety on the time course of attention to emotional stimuli using materials from the International Affective Picture System. Participants with high vs. low trait anxiety (HTA vs. LTA) viewed four categories of pictures simultaneously: dysphoric, threatening, positive, and neutral. Their eye-movements for each emotional stimulus were recorded for static and dynamic analysis. Data were analyzed using a mixed linear model and growth curve analysis. Specifically, the HTA group showed a greater tendency to avoid threatening stimuli and more pupil diameter variation in the early period of stimulus presentation (0–7.9 s). The HTA group also showed a stronger attentional bias toward positive and dysphoric stimuli in the middle and late period of stimulus presentation (7.9–30 s). These results suggest that trait anxiety has a significant temporal effect on attention to emotional stimuli, and that this effect mainly manifests after 7 s. In finding stronger attentional avoidance of threatening stimuli and more changes in neural activity, as well as a stronger attentional bias toward positive stimuli, this study provides novel insights on the relationship between trait anxiety and selective attention. |
Farnaz Zamani Esfahlani; Lisa Byrge; Jacob Tanner; Olaf Sporns; Daniel P. Kennedy; Richard F. Betzel Edge-centric analysis of time-varying functional brain networks with applications in autism spectrum disorder Journal Article In: NeuroImage, vol. 263, pp. 1–12, 2022. @article{ZamaniEsfahlani2022, The interaction between brain regions changes over time, which can be characterized using time-varying functional connectivity (tvFC). The common approach to estimate tvFC uses sliding windows and offers limited temporal resolution. An alternative method is to use the recently proposed edge-centric approach, which enables the tracking of moment-to-moment changes in co-fluctuation patterns between pairs of brain regions. Here, we first examined the dynamic features of edge time series and compared them to those in the sliding window tvFC (sw-tvFC). Then, we used edge time series to compare subjects with autism spectrum disorder (ASD) and healthy controls (CN). Our results indicate that relative to sw-tvFC, edge time series captured rapid and bursty network-level fluctuations that synchronize across subjects during movie-watching. The results from the second part of the study suggested that the magnitude of peak amplitude in the collective co-fluctuations of brain regions (estimated as root sum square (RSS) of edge time series) is similar in CN and ASD. However, the trough-to-trough duration in RSS signal is greater in ASD, compared to CN. Furthermore, an edge-wise comparison of high-amplitude co-fluctuations showed that the within-network edges exhibited greater magnitude fluctuations in CN. Our findings suggest that high-amplitude co-fluctuations captured by edge time series provide details about the disruption of functional brain dynamics that could potentially be used in developing new biomarkers of mental disorders. |
Dan Zhang; Qian Guo; Lihua Xu; Xu Liu; Tian Hong Zhang; Xiaohua Liu; Haiying Chen; Guanjun Li; Jijun Wang The impact of COVID-19 pandemic on individuals at clinical high-risk for psychosis: Evidence from eye-tracking measures Journal Article In: Progress in Neuro-Psychopharmacology and Biological Psychiatry, vol. 118, pp. 1–8, 2022. @article{Zhang2022b, Emerging evidence suggested that people with severe mental disorders were more vulnerable to the negative effects of the COVID-19 pandemic. However, few researches investigated the influence of global pandemics on people at clinical high risk (CHR) for psychosis. This study aimed to investigate the impact of the COVID-19 pandemic on clinical symptoms, psychological distress, and eye-tracking characteristics in CHR individuals and healthy participants. Forty-nine CHR individuals and 50 healthy controls (HC) were assessed by PTSD Checklist for DSM-5 (PCL-5), Perceived Stress Scale, 10-item version (PSS-10), and Coronavirus Impact Scale (CIS). Eye movement performances were measured by the tests of fixation stability, free-viewing, and anti-saccade. According to the mean score of CIS, participants were stratified into high-impact (n = 35) and low-impact (n = 64) subgroups. Compared with the HC group, CHR participants reported significantly higher levels of post-traumatic symptoms caused by the COVID-19 pandemic and showed abnormalities in most of the eye movement indexes. Among the altered indexes, the saccade amplitude of fixation stability test (far distractor), the scan path length of free-viewing test, and the accuracy of anti-saccade test were negatively affected by the severity of impact level in the CHR group. Moreover, the altered eye movement indexes were significantly associated with the total scores of CIS, PCL-5, and subscales of the Scale of Prodromal Syndromes (SOPS) among CHR individuals. Overall, our findings suggested the negative impact of the COVID-19 pandemic on the eye movement characteristics of CHR individuals. The present study provides valuable information on physiological distress related to the COVID-19 pandemic and sensitive neuropsychological biomarkers that interacted with social and environment stress in the CHR population. |
Dan Zhang; Xu Liu; Lihua Xu; Yu Li; Yangyang Xu; Mengqing Xia; Zhenying Qian; Yingying Tang; Zhi Liu; Tao Chen; HaiChun Liu; TianHong Zhang; Jijun Wang Effective differentiation between depressed patients and controls using discriminative eye movement features Journal Article In: Journal of Affective Disorders, vol. 307, pp. 237–243, 2022. @article{Zhang2022c, Background: Depression is a common debilitating mental disorder caused by various factors. Identifying and diagnosing depression are challenging because the clinical evaluation of depression is mainly subjective, lacking objective and quantitative indicators. The present study investigated the value and significance of eye movement measurements in distinguishing depressed patients from controls. Methods: Ninety-five depressed patients and sixty-nine healthy controls performed three eye movement tests, including fixation stability, free-viewing, and anti-saccade tests, and eleven eye movement indexes were obtained from these tests. The independent t-test was adopted for group comparisons, and multiple logistic regression analysis was employed to identify diagnostic biomarkers. Support vector machine (SVM), quadratic discriminant analysis (QDA), and Bayesian (BYS) algorithms were applied to build the classification models. Results: Depressed patients exhibited eye movement anomalies, characterized by increased saccade amplitude in the fixation stability test; diminished saccade velocity in the anti-saccade test; and reduced saccade amplitude, shorter scan path length, lower saccade velocity, decreased dynamic range of pupil size, and lower pupil size ratio in the free-viewing test. Four features mentioned above entered the logistic regression equation. The classification accuracies of SVM, QDA, and BYS models reached 86.0%, 81.1%, and 83.5%, respectively. Conclusions: Depressed patients exhibited abnormalities across multiple tests of eye movements, assisting in differentiating depressed patients from healthy controls in a cost-effective and non-invasive manner. |
Jing Zhu; Changlin Yang; Xiannian Xie; Shiqing Wei; Yizhou Li; Xiaowei Li; Bin Hu Mutual Information Based Fusion Model (MIBFM): Mild depression recognition using EEG and pupil area signals Journal Article In: Journal of LATEX Class Files, vol. 3045, pp. 1–14, 2022. @article{Zhu2022b, The detection of mild depression is conducive to the early intervention and treatment of depression. This study explored the fusion of electroencephalography (EEG) and pupil area signals to build an effective and convenient mild depression recognition model. We proposed Mutual Information Based Fusion Model (MIBFM), which innovatively used pupil area signals to select EEG electrodes based on mutual information. Then we extracted features from EEG and pupil area signals in different bands, and fused bimodal features using the denoising autoencoder. Experimental results showed that MIBFM could obtain the highest accuracy of 87.03%. And MIBFM exhibited better performance than other existing methods. Our findings validate the effectiveness of the use of pupil area as signals, which makes eye movement signals can be easily obtained using high resolution camera, and the EEG electrode selection scheme based on mutual information is also proved to be an applicable solution for data dimension reduction and multimodal complementary information screening. This study casts a new light for mild depression recognition using multimodal data of EEG and pupil area signals, and provides a theoretical basis for the development of portable and universal application systems. |
Jing Zhu; Shiqing Wei; Xiannian Xie; Changlin Yang; Yizhou Li; Xiaowei Li; Bin Hu Content-based multiple evidence fusion on EEG and eye movements for mild depression recognition Journal Article In: Computer Methods and Programs in Biomedicine, vol. 226, pp. 1–11, 2022. @article{Zhu2022a, Background and objective: Depression is a serious neurological disorder that has become a major health problem worldwide. The detection of mild depression is important for the diagnosis of depression in early stages. This research seeks to find a more accurate fusion model which can be used for mild depression detection using Electroencephalography and eye movement data. Methods: This study proposes a content-based multiple evidence fusion (CBMEF) method, which fuses EEG and eye movement data at decision level. The method mainly includes two modules, the classification performance matrix module and the dual-weight fusion module. The classification performance matrices of different modalities are estimated by Bayesian rule based on confusion matrix and Mahalanobis distance, and the matrices were used to correct the classification results. Then the relative conflict degree of each modality is calculated, and different weights are assigned to the above modalities at the decision fusion layer according to this conflict degree. Results: The experimental results show that the proposed method outperforms other fusion methods as well as the single modality results. The highest accuracies achieved 91.12%, and sensitivity, specificity and precision were 89.20%, 93.03%, 92.76%. Conclusions: The promising results showed the potential of the proposed approach for the detection of mild depression. The idea of introducing the classification performance matrix and the dual-weight model to multimodal biosignals fusion casts a new light on the researches of depression recognition. |
Jaimie C. Wilkie; Nathan A. Ryckman; Lynette J. Tippett; Anthony J. Lambert A test of the unified model of vision and attention: Effects of parietal-occipital damage on visual orienting Journal Article In: Neuropsychologia, vol. 168, pp. 1–12, 2022. @article{Wilkie2022, Visual orienting was studied in a patient (FM) with parietal-occipital damage due to oligodendroglioma and associated surgery, and in eighteen control participants. The ability of FM and control participants to shift attention in response to spatial landmark cues, and in response to cues that recruit endogenous orienting via encoding of cue identity, were assessed. According to the unified model of vision and attention (Lambert, A. et al., Journal of Experimental Psychology: Human Perception & Performance, 44, 412–432) FM should find it difficult to orient attention in response to spatial landmarks due to impaired functioning of the dorsal visual stream; but shifting attention in response to cue identity, encoded via the ventral visual stream, should be spared. Consistent with these predictions, FM was unable to shift attention in the landmark cueing task, but shifted attention effectively in response to identity cues; and her visual orienting performance differed reliably from controls. These findings complement our earlier observation of preserved orienting towards landmark cues in a patient with bilateral damage to the ventral visual stream, and add to a growing body of evidence in support of the unified model of vision and attention. |
TianHong Zhang; YingYu Yang; LiHua Xu; XiaoChen Tang; YeGang Hu; Xin Xiong; YanYan Wei; HuiRu Ru Cui; YingYing Tang; HaiChun Liu; Tao Chen; Zhi Liu; Li Hui; ChunBo Li; XiaoLi Guo; JiJun Wang Inefficient integration during multiple facial processing in pre-morbid and early phases of psychosis Journal Article In: The World Journal of Biological Psychiatry, vol. 23, no. 5, pp. 1–13, 2022. @article{Zhang2022j, Objectives: We used eye-tracking to evaluate multiple facial context processing and event-related potential (ERP) to evaluate multiple facial recognition in individuals at clinical high risk (CHR) for psychosis. Methods: In total, 173 subjects (83 CHRs and 90 healthy controls [HCs]) were included and their emotion perception performances were accessed. A total of 40 CHRs and 40 well-matched HCs completed an eye-tracking task where they viewed pictures depicting a person in the foreground, presented as context-free, context-compatible, and context-incompatible. During the two-year follow-up, 26 CHRs developed psychosis, including 17 individuals who developed first-episode schizophrenia (FES). Eighteen well-matched HCs were made to complete the face number detection ERP task with image stimuli of one, two, or three faces. Results: Compared to the HC group, the CHR group showed reduced visual attention to contextual processing when viewing multiple faces. With the increasing complexity of contextual faces, the differences in eye-tracking characteristics also increased. In the ERP task, the N170 amplitude decreased with a higher face number in FES patients, while it increased with a higher face number in HCs. Conclusions: Individuals in the very early phase of psychosis showed facial processing deficits with supporting evidence of different scan paths during context processing and disruption of N170 during multiple facial recognition. |
Hong Zhou; Yunchuang Sun; Luhua Wei; Xia Wang; Yanyan Jiang; Fan Li; Jing Chen; Wei Sun; Lin Zhang; Guiping Zhao; Zhaoxia Wang Quantitative assessment of oculomotor function by videonystagmography in multiple system atrophy Journal Article In: Clinical Neurophysiology, vol. 141, pp. 15–23, 2022. @article{Zhou2022b, Objective: To quantitatively assess oculomotor impairments in multiple system atrophy (MSA) and to explore their correlation with clinical characteristics. Methods: We recruited 45 patients with MSA, including 21 with dominant ataxia (MSA-C), 24 with dominant parkinsonism (MSA-P), and 40 age-matched healthy controls. Detailed oculomotor performance in the horizontal direction was measured using videonystagmography (VNG). Results: We found that the proportion of abnormal eye movements in patients with MSA was 93.3% (37.7%, 51.1%, 73.3%, 71.1%, and 37.8% on fixation and gaze-holding, without fixation, saccade, smooth pursuit, and optokinetic nystagmus tests, respectively). Patients with MSA-C showed significantly lower gains in smooth pursuit test and optokinetic nystagmus test, and a higher incidence of hypermetria in the saccade test than patients with MSA-P (all P < 0.05). No oculomotor deficits were correlated with age, age of onset, sex, disease duration, or Unified Multiple System Atrophy Rating Scale (USMARS) (all r < 0.25, P > 0.1). Conclusions: An extremely high incidence of oculomotor impairments could be observed using VNG in both the MSA-C and MSA-P subtypes, although there were some differences between them. Significance: A comprehensive oculomotor examination could serve as a valuable tool in the diagnostic workup of patients with MSA. |
Chrysanthi Leonidou; Elena Constantinou; Maria Panteli; Georgia Panayiotou Attentional processing of unpleasant stimuli in alexithymia: Early avoidance followed by attention maintenance bias Journal Article In: Cogent Psychology, vol. 9, pp. 1–16, 2022. @article{Leonidou2022, Alexithymia is a multifaceted personality trait linked to increased risk for psychological, psychosomatic, and physical health problems. One hypothesized mechanism through which alexithymia predisposes individuals to such problems is the interference of alexithymic characteristics in processing affective, particularly unpleasant content. This study aimed to investigate the relationship between alexithymia and biases in attentional processing of threatening vs. neutral pictorial stimuli, disentangling early (vigilance) from late (maintenance) attentional biases. One hundred participants (77 female; 18–35 years old) completed the Toronto Alexithymia Scale and underwent a free viewing task with picture pairs presenting illness, fear and neutral content, during which dwell time on each picture was recorded at time intervals of 0–500 ms, 501–1000 ms and 1001–6500 ms of exposure. Results from multilevel modeling showed that alexithymia interacted with time interval and picture type. Higher alexithymia scores were related to less dwell time towards fear pictures at 501 ms-1000 ms, but more dwell time at 1001 ms-6500 ms after stimulus onset. This effect was particularly observed for the externally oriented thinking and the difficulty in describing feelings facets of alexithymia, but not the difficulty in identifying feelings. There was no effect of alexithymia on early vigilance at 0–500 ms. This study provides evidence on the association between alexithymic traits and early avoidance, along with late maintenance bias to fear, which appears consistent with the view that alexithymia is associated with avoidant emotion regulation processes, but also greater requirements of cognitive resources for processing affective information. |
Astar Lev; Yoram Braw; Tomer Elbaum; Michael Wagner; Yuri Rassovsky Eye tracking during a continuous performance test: Utility for assessing ADHD patients Journal Article In: Journal of Attention Disorders, vol. 26, no. 2, pp. 245–255, 2022. @article{Lev2022, Objective: The use of continuous performance tests (CPTs) for assessing ADHD related cognitive impairment is ubiquitous. Novel psychophysiological measures may enhance the data that is derived from CPTs and thereby improve clinical decision-making regarding diagnosis and treatment. As part of the current study, we integrated an eye tracker with the MOXO-dCPT and assessed the utility of eye movement measures to differentiate ADHD patients and healthy controls. Method: Adult ADHD patients and gender/age-matched healthy controls performed the MOXO-dCPT while their eye movements were monitored (n = 33 per group). Results: ADHD patients spent significantly more time gazing at irrelevant regions, both on the screen and outside of it, than healthy controls. The eye movement measures showed adequate ability to classify ADHD patients. Moreover, a scale that combined eye movement measures enhanced group prediction, compared to the sole use of conventional MOXO-dCPT indices. Conclusions: Integrating an eye tracker with CPTs is a feasible way of enhancing diagnostic precision and shows initial promise for clarifying the cognitive profile of ADHD patients. Pending replication, these findings point toward a promising path for the evolution of existing CPTs. |
Astar Lev; Tomer Elbaum; Corinne Berger; Yoram Braw Feigned ADHD associated cognitive impairment: Utility of integrating an eye-tracker and the MOXO-dCPT Journal Article In: Journal of Attention Disorders, vol. 26, no. 9, pp. 1–11, 2022. @article{Lev2022a, Objective: The current study assessed the utility of eye-movements measures, gathered while participants performed a commercially available Continuous Performance Test (CPT), to detect feigned ADHD-associated cognitive impairment. Method: Healthy simulators (n = 37), ADHD patients (n = 33), and healthy controls (n = 36) performed an eye-tracker integrated MOXO-dCPT and a stand-alone validity indicator. Results: Simulators gazed significantly longer at regions that were irrelevant for successful MOXO-dCPT performance compared to ADHD patients and healthy controls. This eye-movement measure, however, had lower sensitivity than traditional MOXO-dCPT indices. Discussion: Gaze direction measures, gathered while performing a CPT, show initial promise as validity indicators. Traditional CPT measures, however, are more sensitive and therefore offer a more promising path for the establishment of CPT-based validity indicators. The current study is an initial exploration of the issue and further evaluation of both theoretical and practical aspects is mandated. |
Wei Li; Hannah Rohde; Martin Corley Veritable untruths: Autistic traits and the processing of deception Journal Article In: Journal of Autism and Developmental Disorders, vol. 52, pp. 4921–4930, 2022. @article{Li2022g, How do we decide whether a statement is literally true? Here, we contrast participants' eventual evaluations of a speaker's meaning with the real-time processes of comprehension. We record participants' eye movements as they respond to potentially misleading instructions to click on one of two objects which might be concealing treasure (the treasure is behind thee, uh, hat). Participants are less likely to click on the named object when the instructions are disfluent. However, when hearing disfluent utterances, a tendency to fixate the named object early increases with participants' autism quotient scores. This suggests that, even where utterances are equivalently understood, the processes by which interpretations are achieved vary across individuals. |
Jia Liu; Jinsheng Hu; Qi Li; Xiaoning Zhao; Ying Liu; Shuqing Liu Atypical processing pattern of gaze cues in dynamic situations in autism spectrum disorders Journal Article In: Scientific Reports, vol. 12, pp. 1–11, 2022. @article{Liu2022b, Psychological studies have generally shown that individuals with Autism Spectrum Disorder (ASD) have particularity in the processing of social information by using static or abstract images. Yet, a recent study showed that there was no difference in their use of social or non-social cues in dynamic interactive situations. To establish the cause of the inconsistent results, we added gaze cues in different directions to the chase detection paradigm to explore whether they would affect the performance of participants with ASD. Meanwhile, eye-tracking methodology was used to investigate whether the processing patterns of gaze cues were different between individuals with ASD and TD. In this study, unlike typical controls, participants with ASD showed no detection advantage when the direction of gaze was consistent with the direction of movement (oriented condition). The results suggested that individuals with ASD may utilize an atypical processing pattern, which makes it difficult for them to use social information contained in oriented gaze cues in dynamic interactive situations. |
Floor C. Loonstra; Lodewijk R. J. De Ruiter; Djoeke Doesburg; Ka-Hoo Lam; Zoe Y. G. J. Van Lierop; Bastiaan Moraal; Eva M. M. Strijbis; Joep Killestein; Bernard M. J. Uitdehaag Project Y: The search for clues explaining phenotype variability in MS Journal Article In: Multiple Sclerosis and Related Disorders, vol. 57, pp. 1–8, 2022. @article{Loonstra2022, Background: To study phenotypic variability in MS patients, well-defined unbiased cohort studies are necessary. The most common and probably most important confounding factor when studying disease phenotype in MS is age. Objective: To describe study design and subject characteristics of a unique birth cohort (Project Y). The overall aim of Project Y is to identify determinants associated with phenotypic variability in MS, eliminating the possibility of confounding by age. Methods: Project Y is a population-based cross-sectional study of all people with MS born in the Netherlands in 1966. Patients and healthy controls were subjected to comprehensive examinations: functional and static imaging, physical and cognitive measurements, and lifestyle factors early and later in life. In addition body fluids were collected and stored for future biomarker research. Results: 452 eligible MS patients were identified. Between December 2017 and January 2021, 367 MS patients and 125 healthy controls participated. The total number of identified cases results in a current prevalence of at least 189/100.000 for people born in the year 1966 in The Netherlands. Conclusion: Project Y is a unique cohort designed to identify factors associated with phenotypic variability in MS patients without the confounding effects of age. This first description of the Project Y cohort indicates that the prevalence of MS in the Netherlands might be higher than previously presumed. Various studies using Project Y data are ongoing and results will be published in upcoming years. |
Joel T. Martin; Annalise H. Whittaker; Stephen J. Johnston Pupillometry and the vigilance decrement: Task-evoked but not baseline pupil measures reflect declining performance in visual vigilance tasks Journal Article In: European Journal of Neuroscience, vol. 55, no. 3, pp. 778–799, 2022. @article{Martin2022, Baseline and task-evoked pupil measures are known to reflect the activity of the nervous system's central arousal mechanisms. With the increasing availability, affordability and flexibility of video-based eye tracking hardware, these measures may one day find practical application in real-time biobehavioural monitoring systems to assess performance or fitness for duty in tasks requiring vigilant attention. But real-world vigilance tasks are predominantly visual in their nature and most research in this area has taken place in the auditory domain. Here, we explore the relationship between pupil size—both baseline and task-evoked—and behavioural performance measures in two novel vigilance tasks requiring visual target detection: (1) a traditional vigilance task involving prolonged, continuous and uninterrupted performance (n = 28) and (2) a psychomotor vigilance task (n = 25). In both tasks, behavioural performance and task-evoked pupil responses declined as time spent on task increased, corroborating previous reports in the literature of a vigilance decrement with a corresponding reduction in task-evoked pupil measures. Also in line with previous findings, baseline pupil size did not show a consistent relationship with performance measures. Our data offer novel insights into the complex interplay of brain systems involved in vigilant attention and question the validity of the assumption that baseline (prestimulus) pupil size and task-evoked (poststimulus) pupil measures reflect the tonic and phasic firing modes of the locus coeruleus. |
Walker S. McKinney; Shannon E. Kelly; Kathryn E. Unruh; Robin L. Shafer; John A. Sweeney; Martin Styner; Matthew W. Mosconi Cerebellar volumes and sensorimotor behavior in autism spectrum disorder Journal Article In: Frontiers in Integrative Neuroscience, vol. 16, pp. 1–16, 2022. @article{McKinney2022, Background: Sensorimotor issues are common in autism spectrum disorder (ASD), though their neural bases are not well understood. The cerebellum is vital to sensorimotor control and reduced cerebellar volumes in ASD have been documented. Our study examined the extent to which cerebellar volumes are associated with multiple sensorimotor behaviors in ASD. Materials and Methods: Fifty-eight participants with ASD and 34 typically developing (TD) controls (8–30 years) completed a structural MRI scan and precision grip testing, oculomotor testing, or both. Force variability during precision gripping as well as absolute error and trial-to-trial error variability of visually guided saccades were examined. Volumes of cerebellar lobules, vermis, and white matter were quantified. The relationships between each cerebellar region of interest (ROI) and force variability, saccade error, and saccade error variability were examined. Results: Relative to TD controls, individuals with ASD showed increased force variability. Individuals with ASD showed a reduced volume of cerebellar vermis VI-VII relative to TD controls. Relative to TD females, females with ASD showed a reduced volume of bilateral cerebellar Crus II/lobule VIIB. Increased volume of Crus I was associated with increased force variability. Increased volume of vermal lobules VI-VII was associated with reduced saccade error for TD controls but not individuals with ASD. Increased right lobule VIII and cerebellar white matter volumes as well as reduced right lobule VI and right lobule X volumes were associated with greater ASD symptom severity. Reduced volumes of right Crus II/lobule VIIB were associated with greater ASD symptom severity in only males, while reduced volumes of right Crus I were associated with more severe restricted and repetitive behaviors only in females. Conclusion: Our finding that increased force variability in ASD is associated with greater cerebellar Crus I volumes indicates that disruption of sensory feedback processing supported by Crus I may contribute to skeletomotor differences in ASD. Results showing that volumes of vermal lobules VI-VII are associated with saccade precision in TD but not ASD implicates atypical organization of the brain systems supporting oculomotor control in ASD. Associations between volumes of cerebellar subregions and ASD symptom severity suggest cerebellar pathological processes may contribute to multiple developmental challenges in ASD. |
Drew J. McLaughlin; Maggie E. Zink; Lauren Gaunt; Brent Spehar; Kristin J. Van Engen; Mitchell S. Sommers; Jonathan E. Peelle Pupillometry reveals cognitive demands of lexical competition during spoken word recognition in young and older adults Journal Article In: Psychonomic Bulletin & Review, vol. 29, no. 1, pp. 1–13, 2022. @article{McLaughlin2022, In most contemporary activation-competition frameworks for spoken word recognition, candidate words compete against phonological “neighbors” with similar acoustic properties (e.g., “cap” vs. “cat”). Thus, recognizing words with more competitors should come at a greater cognitive cost relative to recognizing words with fewer competitors, due to increased demands for selecting the correct item and inhibiting incorrect candidates. Importantly, these processes should operate even in the absence of differences in accuracy. In the present study, we tested this proposal by examining differences in processing costs associated with neighborhood density for highly intelligible items presented in quiet. A second goal was to examine whether the cognitive demands associated with increased neighborhood density were greater for older adults compared with young adults. Using pupillometry as an index of cognitive processing load, we compared the cognitive demands associated with spoken word recognition for words with many or fewer neighbors, presented in quiet, for young (n = 67) and older (n = 69) adult listeners. Growth curve analysis of the pupil data indicated that older adults showed a greater evoked pupil response for spoken words than did young adults, consistent with increased cognitive load during spoken word recognition. Words from dense neighborhoods were marginally more demanding to process than words from sparse neighborhoods. There was also an interaction between age and neighborhood density, indicating larger effects of density in young adult listeners. These results highlight the importance of assessing both cognitive demands and accuracy when investigating the mechanisms underlying spoken word recognition. |
Charlotte Elisabeth Piechaczek; Pia Theresa Schröder; Lisa Feldmann; Gerd Schulte-Körne; Ellen Greimel The effects of attentional deployment on reinterpretation in depressed adolescents: Evidence from an eye-tracking study Journal Article In: Cognitive Therapy and Research, vol. 46, pp. 967–982, 2022. @article{Piechaczek2022, Background: Individuals with major depression have difficulties employing cognitive reappraisal. Most prior studies have not accounted for attentional deployment, which seems to be involved in this process. Methods: We investigated the cognitive reappraisal tactic reinterpretation in 20 depressed and 28 healthy youths and assessed regulation success in response to negative pictures via self-report. To investigate attentional deployment during reinterpretation, we applied eye-tracking and manipulated gaze focus by instructing participants to direct their attention towards/away from emotional picture aspects. Results: Depressed adolescents, compared with healthy youths, had a diminished regulation success when their gaze was focused on emotional aspects. Both depressed and healthy adolescents spent less time fixating on emotional facets of negative pictures when using reinterpretation as compared with simply attending to the pictures. Conclusions: Results from this study suggest that adolescents with major depression have emotion regulation deficits when being confronted with negative emotional facets, while showing intact overt attentional processes. The findings provide important starting points for future research investigating the role of other factors which might impact on emotion regulation processes in this patient group, such as cognitive control deficits. |
Alessandro Piras; Aurelio Trofè; Andrea Meoni; Milena Raffi Influence of radial optic flow stimulation on static postural balance in Parkinson's disease: A preliminary study Journal Article In: Human Movement Science, vol. 81, pp. 1–11, 2022. @article{Piras2022, The role of optic flow in the control of balance in persons with Parkinson's disease (PD) has yet to be studied. Since basal ganglia are understood to have a role in controlling ocular fixation, we have hypothesized that persons with PD would exhibit impaired performance in fixation tasks, i.e., altered postural balance due to the possible relationships between postural disorders and visual perception. The aim of this preliminary study was to investigate how people affected by PD respond to optic flow stimuli presented with radial expanding motion, with the intention to see how the stimulation of different retinal portions may alter the static postural sway. We measured the body sway using center of pressure parameters recorded from two force platforms during the presentation of the foveal, peripheral and full field radial optic flow stimuli. Persons with PD had different visual responses in terms of fixational eye movement characteristics, with greater postural alteration in the sway area and in the medio-lateral direction than the age-matched control group. Balance impairment in the medio-lateral oscillation is often observed in persons with atypical Parkinsonism, but not in Parkinson's disease. Persons with PD are more dependent on visual feedback with respect to age-matched control subjects, and this could be due to their impaired peripheral kinesthetic feedback. Visual stimulation of standing posture would provide reliable signs in the differential diagnosis of Parkinsonism. |
Barbara L. Pitts; Michelle L. Eisenberg; Heather R. Bailey; Jeffrey M. Zacks PTSD is associated with impaired event processing and memory for everyday events Journal Article In: Cognitive Research: Principles and Implications, vol. 7, pp. 1–13, 2022. @article{Pitts2022, Current theories of posttraumatic stress disorder (PTSD) propose that memory abnormalities are central to the development and persistence of symptoms. While the most notable memory disturbances in PTSD involve memory for the trauma itself, individuals often have trouble remembering aspects of everyday life. Further, people with PTSD may have difficulty segmenting ongoing activity into discrete units, which is important for our perception and later memory of the activity. The current study investigated whether PTSD diagnosis and symptom severity predicted event segmentation and memory for everyday activities. To do so, 63 people with PTSD and 64 controls with a trauma history watched, segmented, and recalled videos of everyday activities. Viewers with higher PTSD symptom severity showed lower agreement on locations of event boundaries and recalled fewer fine-grained actions than did those with lower symptom severity. These results suggest that PTSD symptoms alter event segmentation, which may contribute to subsequent memory disturbances. |
Sophia Antonia Press; Stefanie C. Biehl; C. Carolyn Vatheuer; Gregor Domes; Jennifer Svaldi Neural correlates of body image processing in binge eating disorder Journal Article In: Journal of Psychopathology and Clinical Science, vol. 131, no. 4, pp. 350–364, 2022. @article{Press2022, Although body image disturbances play a central role in the development, maintenance and relapse of binge eating disorder (BED), studies investigating the neural basis underlying body processing in BED are still missing. To address this gap, we conducted a preregistered (German Clinical Trials Register [Deutsches Register Klinischer Studien; DRKS], Registration DRKS00008107) combined functional magnetic resonance (fMRI)/eye tracking study in which 38 women with BED and 22 healthy controls weight-matched for overall equivalence processed images of their own bodies, an unfamiliar weight- matched body, and visually matched nonbody control stimuli while performing a one-back task. Women with BED responded with higher left fusiform body area (FBA) activity than controls during body image processing. Despite higher levels of self-reported body dissatisfaction, women with BED did not show overactivation in emotion-processing areas in response to their own body. The eye-track- ing results indicated that visual attention toward the presented stimuli was associated with increased ac- tivity in the extrastriate body area (EBA) and FBA across groups. Our results thus provide evidence for an aberrant neural processing of body images in BED and highlight the importance of controlling for visual attention in future studies assessing neuronal body processing. |
Xiao-jing Qin; Jia-li Liu; Ji-fang Cui; Hai-song Shi; Jun-yan Ye; Tian-xiao Yang; Ya Wang Prospective memory performance and its improvement in individuals with high schizotypal traits: Evidence from eye-tracking studies Journal Article In: Clinical Neurophysiology, vol. 143, pp. 133–142, 2022. @article{Qin2022, Objective: This study aimed to examine prospective memory (PM) performance and the potential effect of implementation intention on PM performance and the underlying mechanisms in individuals with high schizotypyal traits (HSTs) using eye-tracking paradigms. Methods: In Experiment 1, 30 individuals with HSTs and 30 individuals with low schizotypal traits (LSTs) underwent a visual search task that involved PM cues, and participants' eye movements were recorded. In Experiment 2, 50 individuals with HSTs were randomly assigned to the implementation intention group and typical instruction group. Results: In Experiment 1, individuals with HSTs had a lower PM accuracy and performed less PM cue monitoring (indicated by fewer total fixation counts on distractor words) than individuals with LSTs. In Experiment 2, implementation intention significantly improved PM accuracy and increased total fixation counts on distractor words in individuals with HSTs compared to the HST group with typical instruction. Conclusions: Individuals with HSTs were impaired in PM and showed reduced cue monitoring compared to individuals with LSTs. Implementation intention improved PM performance and facilitated cue monitoring in individuals with HSTs. Significance: Our findings indicate that cue monitoring may be an important process of intervention target for PM for individuals in the schizophrenia spectrum. |
Hanane Ramzaoui; Sylvane Faure; Renaud David; Sara Spotorno Top-down and bottom-up sources of eye-movement guidance during realistic scene search in Alzheimer's disease Journal Article In: Neuropsychology, vol. 36, no. 7, pp. 597–613, 2022. @article{Ramzaoui2022, Objective: Visual search is a crucial task in daily life, but in Alzheimer's disease (AD) it has usually been investigated using simple arrays. Here, we used scenes depicting real environments and studied the time course of attentional guidance. Method: We analyzed eye-movement differences between mild AD patients and age-matched healthy controls during search. We examined top-down guidance, manipulating the target template (precise picture vs. word cue) and the target-scene semantic consistency (consistent vs. inconsistent), and bottom-up guidance, manipulating the perceptual salience (high vs. low) of targets and distractors. Results: During scene scanning, AD patients had longer search times, made more fixations before the first target fixation, and showed a greater probability of distractor selection, with longer distractor fixation. AD also led to longer target fixation. In patients and controls, picture cues and highly salient targets improved all search phases, whereas consistent targets only improved search initiation (first saccade). Moreover, topdown and bottom-up guidance interacted in initiation and scanning, and this did not differ between the two groups of participants. However, AD led to a smaller picture cue benefit in shortening distractor fixation and greater bottom-up search facilitation during scanning, where a high-salience target reduced the performance gap between patients and controls. Conclusions: Our study shows the importance of top-down and bottomup guidance, and their integration, in improving search in AD patients. It suggests that precise target cues and, even more, highly salient targets may act as environmental supports that enhance attentional processing and search performance. |
Ileana Ratiu; Schea Fissel-Brannick; Miyka Whiting; Lindsay Murnion; Tamiko Azuma The impact of mild traumatic brain injury on reading comprehension and eye movements: preliminary results Journal Article In: Journal of Communication Disorders, vol. 96, pp. 1–18, 2022. @article{Ratiu2022, Introduction: Individuals who sustain a mild traumatic brain injury (mTBI) can suffer from executive function, working memory, and attention deficits, which can impact functional task performance, including reading comprehension. Individuals with mTBI commonly report reading difficulties, but such difficulties have been historically difficult to capture using behavioral measures. The current study examined reading performance in those with and without mTBI using eye-tracking measures, which may be more sensitive to reading impairment in mTBI. Method/Results: In Experiment 1, 26 participants with a history of mTBI and 26 healthy control participants completed working memory (WM) and reading comprehension tasks. We found no differences in behavioral measures but found that spontaneous eye-blinking frequency was lower during the reading task in the mTBI group. In Experiment 2, we explored the impact of auditory distraction (e.g., multi-talker babble) on reading and memory performance. Twenty-three new participants with a history of mTBI and 26 healthy control participants completed a short-term memory (STM) task, a WM task, and a reading comprehension task under two distraction conditions. As in Experiment 1, we found no differences on behavioral measures, but observed significant differences on spontaneous eye-blinking frequency between those with and without mTBI. Group differences in distraction effects were also observed and performance on the WM task predicted reading comprehension performance. Conclusions: The lack of differences on behavioral measures between groups, but lower frequencies of spontaneous eye blinking in the mTBI group suggests that while these individuals successfully completed the reading comprehension task, they may require more cognitive resources to do so. |
Mariel Roberts; Marisa Carrasco Exogenous attention generalizes location transfer of perceptual learning in adults with amblyopia Journal Article In: iScience, vol. 25, no. 3, pp. 1–29, 2022. @article{Roberts2022, Visual perceptual learning (VPL) is a behavioral manifestation of brain neuroplasticity. However, its practical effectiveness is limited because improvements are often specific to the trained conditions and require significant time and effort. It is critical to understand the conditions that promote learning and transfer. Covert endogenous (voluntary) and exogenous (involuntary) spatial attention help overcome VPL location specificity in neurotypical adults, but whether they also do so for people with atypical visual development is unknown. This study investigates the role of exogenous attention during VPL in adults with amblyopia, an ideal population given their asymmetrically developed, but highly plastic, visual cortex. Here we show that training on a discrimination task leads to improvements in foveal contrast sensitivity, acuity, and stereoacuity. Notably, exogenous attention helps generalize learning beyond trained spatial locations. Future large-scale studies can verify the extent to which attention enhances the effectiveness of perceptual learning during rehabilitation of visual disorders. |
Oded Rock; Andrea Albonico; Farnaz Javadian; Mohammad Ashkanani; Alisdair J. G. Taylor; Michael Dreyer; Jason J. S. Barton Oblique saccades in internuclear ophthalmoplegia Journal Article In: Experimental Brain Research, vol. 240, no. 3, pp. 861–869, 2022. @article{Rock2022, Purpose: Oblique saccades often display component stretching, in which the shorter vector in one cardinal direction is slowed so that its duration matches that of the longer vector in the orthogonal direction, resulting in a straighter trajectory. In internuclear ophthalmoplegia, adducting saccades are typically slowed while vertical saccades are unaffected. It is not known whether these slowed adducting movements are accompanied by adaptive component stretching of the vertical vector during oblique saccades. This was a cross-sectional study. We recorded the saccadic eye movement in 5 patients with right or bilateral internuclear ophthalmoplegia from multiple sclerosis and 17 healthy controls, using an EyeLink 1000 machine. The target stimulus was located at varying angles (0–360) and amplitudes (4, 8, 12 degrees). For each saccade we have calculated the curvature index as the main outcome measure, which is the area between the actual and ideal straight trajectory for oblique saccadic eye movements, divided by the square of the length of the straight trajectory, to give a unit-less metric for curvature. In the 17 control subjects, curvature showed a strong positive correlation between adducting saccades and the yoked abducting saccades of the other eye. In internuclear ophthalmoplegia, adducting saccades showed a strong curvature concave to the horizontal meridian, indicating inadequate component stretching, while abducting saccades did not differ from controls. This new sign of oblique saccadic curvature in internuclear ophthalmoplegia indicates a limitation of the range of central adaptive changes in response to distal lesions affecting transmission of the saccadic command. |
Anat Rudich-Strassler; Nimrod Hertz-Palmor; Amit Lazarov Looks interesting: Attention allocation in depression when using a news website – An eye tracking study Journal Article In: Journal of Affective Disorders, vol. 304, pp. 113–121, 2022. @article{RudichStrassler2022, Background: Eye-tracking-based attention research has shown attentional biases toward dysphoric and away from positive stimuli in depression. However, most research used prototypical stimuli (co-presented contrasting emotional faces/pictures), less reflective of real-life situations. The current study addressed this limitation by examining participants' attentional allocation patterns while freely viewing a news website containing dysphoric and positive news articles. Methods: Participants with high levels of depression (HD; n = 30) and with minimal levels of depression (MD; n = 30) freely viewed a fictitious news website for 3.5 min, containing six articles (picture + text) with dysphoric content and six with positive content. Gaze patterns on corresponding areas of interest (AOIs) were compared. Following the task, participants rated each article's valence, authenticity, and interest. Results: Compared to MD participants, HD participants spent more time dwelling on dysphoric articles and less time dwelling on positive articles. Within group analyses showed that while HD participants spent more time dwelling on dysphoric compared to positive articles, MD participants showed no preference, allocating their attention equally to both article types. Echoing within-group gaze patterns, HD participants rated the dysphoric articles as being more interesting than the positive articles, while MD participants rated both types of articles as being equally interesting. Conclusion: Attentional biases in depression were also evident when using a more ecologically valid task such as viewing a news website, manifesting as increase attention allocation to dysphoric over positive content. This attention pattern may be related to corresponding differences in the level of interest participants found in each article type. |
Uzma Samadani; Robert J. Spinner; Gerard Dynkowski; Susan Kirelik; Tory Schaaf; Stephen P. Wall; Paul Huang Eye tracking for classification of concussion in adults and pediatrics Journal Article In: Frontiers in Neurology, vol. 13, no. 2, pp. 1–6, 2022. @article{Samadani2022, INTRODUCTION In order to obtain FDA Marketing Authorization for aid in the diagnosis of concussion, an eye tracking study in an intended use population was conducted. METHODS Potentially concussed subjects recruited in emergency department and concussion clinic settings prospectively underwent eye tracking and a subset of the Sport Concussion Assessment Tool 3 at 6 sites. The results of an eye tracking-based classifier model were then validated against a pre-specified algorithm with a cutoff for concussed vs. non-concussed. The sensitivity and specificity of eye tracking were calculated after plotting of the receiver operating characteristic curve and calculation of the AUC (area under curve). RESULTS When concussion is defined by SCAT3 subsets, the sensitivity and specificity of an eye tracking algorithm was 80.4 and 66.1%, The AUC was 0.718. The misclassification rate (n = 282) was 31.6%. CONCLUSION A pre-specified algorithm and cutoff for diagnosis of concussion vs. non-concussion has a sensitivity and specificity that is useful as a baseline-free aid in diagnosis of concussion. Eye tracking has potential to serve as an objective "gold-standard" for detection of neurophysiologic disruption due to brain injury. |
Arunava Samaddar; Brooke S. Jackson; Christopher J. Helms; Nicole A. Lazar; Jennifer E. McDowell; Cheolwoo Park A group comparison in fMRI data using a semiparametric model under shape invariance Journal Article In: Computational Statistics and Data Analysis, vol. 167, pp. 1–18, 2022. @article{Samaddar2022, In the analysis of functional magnetic resonance imaging (fMRI) data, a common type of analysis is to compare differences across scanning sessions. A challenge to direct comparisons of this type is the low signal-to-noise ratio in fMRI data. By using the property that brain signals from a task-related experiment may exhibit a similar pattern in regions of interest across participants, a semiparametric approach under shape invariance to quantify and test the differences in sessions and groups is developed. The common function is estimated with local polynomial regression and the shape invariance model parameters are estimated using evolutionary optimization methods. The efficacy of the semi-parametric approach is demonstrated on a study of brain activation changes across two sessions associated with practice-related cognitive control. The objective of the study is to evaluate neural circuitry supporting a cognitive control task, and associated practice-related changes via acquisition of blood oxygenation level dependent (BOLD) signal collected using fMRI. By using the proposed approach, BOLD signals in multiple regions of interest for control participants and participants with schizophrenia are compared as they perform a cognitive control task (known as the antisaccade task) at two sessions, and the effects of task practice in these groups are quantified. |
Daniela Canu; Chara Ioannou; Katarina Müller; Berthold Martin; Christian Fleischhaker; Monica Biscaldi; André Beauducel; Nikolaos Smyrnis; Ludger Tebartz Elst; Christoph Klein Visual search in neurodevelopmental disorders: Evidence towards a continuum of impairment Journal Article In: European Child and Adolescent Psychiatry, vol. 31, no. 8, pp. 1–18, 2022. @article{Canu2022a, Disorders with neurodevelopmental aetiology such as Attention-Deficit/Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD) and Schizophrenia share commonalities at many levels of investigation despite phenotypic differences. Evidence of genetic overlap has led to the concept of a continuum of neurodevelopmental impairment along which these disorders can be positioned in aetiological, pathophysiological and developmental features. This concept requires their simultaneous comparison at different levels, which has not been accomplished so far. Given that cognitive impairments are core to the pathophysiology of these disorders, we provide for the first time differentiated head-to-head comparisons in a complex cognitive function, visual search, decomposing the task with eye movement-based process analyses. N = 103 late-adolescents with schizophrenia, ADHD, ASD and healthy controls took a serial visual search task, while their eye movements were recorded. Patients with schizophrenia presented the greatest level of impairment across different phases of search, followed by patients with ADHD, who shared with patients with schizophrenia elevated intra-subject variability in the pre-search stage. ASD was the least impaired group, but similar to schizophrenia in post-search processes and to schizophrenia and ADHD in pre-search processes and fixation duration while scanning the items. Importantly, the profiles of deviancy from controls were highly correlated between all three clinical groups, in line with the continuum idea. Findings suggest the existence of one common neurodevelopmental continuum of performance for the three disorders, while quantitative differences appear in the level of impairment. Given the relevance of cognitive impairments in these three disorders, we argue in favour of overlapping pathophysiological mechanisms. |
Daniela Canu; Chara Ioannou; Katarina Müller; Berthold Martin; Christian Fleischhaker; Monica Biscaldi; André Beauducel; Nikolaos Smyrnis; Ludger Tebartz Elst; Christoph Klein Evidence towards a continuum of impairment across neurodevelopmental disorders from basic ocular-motor tasks Journal Article In: Scientific Reports, vol. 12, no. 1, pp. 1–17, 2022. @article{Canu2022, Findings of genetic overlap between Schizophrenia, Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) contributed to a renewed conceptualization of these disorders as laying on a continuum based on aetiological, pathophysiological and neurodevelopmental features. Given that cognitive impairments are core to their pathophysiology, we compared patients with schizophrenia, ADHD, ASD, and controls on ocular-motor and manual-motor tasks, challenging crucial cognitive processes. Group comparisons revealed inhibition deficits common to all disorders, increased intra-subject variability in schizophrenia and, to a lesser extent, ADHD as well as slowed processing in schizophrenia. Patterns of deviancies from controls exhibited strong correlations, along with differences that posited schizophrenia as the most impaired group, followed by ASD and ADHD. While vector correlations point towards a common neurodevelopmental continuum of impairment, vector levels suggest differences in the severity of such impairment. These findings argue towards a dimensional approach to Neurodevelopmental Disorders' pathophysiological mechanisms. |
Matthew R. Cavanaugh; Duje Tadin; Marisa Carrasco; Krystel R. Huxlin Benefits of endogenous spatial attention during visual double-training in cortically-blinded fields Journal Article In: Frontiers in Neuroscience, vol. 16, pp. 1–14, 2022. @article{Cavanaugh2022, Recovery of visual discrimination thresholds inside cortically-blinded (CB) fields is most commonly attained at a single, trained location at a time, with iterative progress deeper into the blind field as performance improves over several months. As such, training is slow, inefficient, burdensome, and often frustrating for patients. Here, we investigated whether double-location training, coupled with a covert spatial-attention (SA) pre-cue, could improve the efficiency of training. Nine CB participants completed a randomized, training assignment with either a spatial attention or neutral pre-cue. All trained for a similar length of time on a fine direction discrimination task at two blind field locations simultaneously. Training stimuli and tasks for both cohorts were identical, save for the presence of a central pre-cue, to manipulate endogenous (voluntary) SA, or a Neutral pre-cue. Participants in the SA training cohort demonstrated marked improvements in direction discrimination thresholds, albeit not to normal/intact-field levels; participants in the Neutral training cohort remained impaired. Thus, double-training within cortically blind fields, when coupled with SA pre-cues can significantly improve direction discrimination thresholds at two locations simultaneously, offering a new method to improve performance and reduce the training burden for CB patients. Double-training without SA pre-cues revealed a hitherto unrecognized limitation of cortically-blind visual systems' ability to improve while processing two stimuli simultaneously. These data could potentially explain why exposure to the typically complex visual environments encountered in everyday life is insufficient to induce visual recovery in CB patients. It is hoped that these new insights will direct both research and therapeutic developments toward methods that can attain better, faster recovery of vision in CB fields. |
Alexis Cheviet; Jana Masselink; Eric Koun; Roméo Salemme; Markus Lappe; Caroline Froment-Tilikete; Denis Pélisson Cerebellar signals drive motor adjustments and visual perceptual changes during forward and backward adaptation of reactive saccades Journal Article In: Cerebral Cortex, vol. 32, no. 18, pp. 3896–3916, 2022. @article{Cheviet2022, Saccadic adaptation (SA) is a cerebellar-dependent learning of motor commands (MC), which aims at preserving saccade accuracy. Since SA alters visual localization during fixation and even more so across saccades, it could also involve changes of target and/or saccade visuospatial representations, the latter (CDv) resulting from a motor-to-visual transformation (forward dynamics model) of the corollary discharge of the MC. In the present study, we investigated if, in addition to its established role in adaptive adjustment of MC, the cerebellum could contribute to the adaptation-associated perceptual changes. Transfer of backward and forward adaptation to spatial perceptual performance (during ocular fixation and trans-saccadically) was assessed in eight cerebellar patients and eight healthy volunteers. In healthy participants, both types of SA altered MC as well as internal representations of the saccade target and of the saccadic eye displacement. In patients, adaptation-related adjustments of MC and adaptation transfer to localization were strongly reduced relative to healthy participants, unraveling abnormal adaptation-related changes of target and CDv. Importantly, the estimated changes of CDv were totally abolished following forward session but mainly preserved in backward session, suggesting that an internal model ensuring trans-saccadic localization could be located in the adaptation-related cerebellar networks or in downstream networks, respectively. |
Amy Chow; Rajkumar Nallour Raveendran; Ian Erkelens; Raiju Babu; Benjamin Thompson Increased saccadic latency in Amblyopia: Oculomotor and attentional factors Journal Article In: Vision Research, vol. 197, pp. 1–11, 2022. @article{Chow2022, Amblyopia is a neurodevelopmental disorder of vision that arises from disrupted binocular vision during early childhood. Delayed initiation of saccadic eye movements is an established feature of amblyopia. The present study investigated whether oculomotor and/or attentional factors contribute to increased amblyopic eye saccadic latencies. Participants with normal vision (n = 10) and amblyopia (n = 10; 4 anisometropia, 6 strabismic/mixed) performed visually-guided saccades to targets presented via a mirror haploscope. Eye movements were recorded for both eyes even under monocular viewing conditions. In Experiment 1, we measured the latency, amplitude gain and peak velocity of saccades as targets were presented binocularly, or monocularly. Saccadic latencies were significantly longer for both eyes when targets were presented to only the amblyopic eye compared to all other conditions. Saccade gain and main sequence rate constants were similar across groups for all viewing conditions. In Experiment 2, we tested the hypothesis that shifts of overt attention may be deficient when viewing with the amblyopic eye. We presented the fixation target to one eye and the subsequent peripheral target (saccadic error signal) to the other eye. Shifting saccadic targets between the eyes expedited saccadic latencies irrespective of which eye viewed the target in the amblyopia group. These findings indicate that oculomotor factors related to saccade generation are unlikely to be responsible for amblyopic eye saccadic latency delays. We propose that an impairment in the ability to disengage attention from a fixation target and orient to a peripheral target when both targets are seen by the amblyopic eye may contribute to increased saccadic latency. |
Francesco Cimminella; Giorgia D'Innocenzo; Sergio Della Sala; Alessandro Iavarone; Caterina Musella; Moreno I. Coco Preserved extra-foveal processing of object semantics in Alzheimer's disease Journal Article In: Journal of Geriatric Psychiatry and Neurology, vol. 35, no. 3, pp. 418–433, 2022. @article{Cimminella2022, Alzheimer's disease (AD) patients underperform on a range of tasks requiring semantic processing, but it is unclear whether this impairment is due to a generalised loss of semantic knowledge or to issues in accessing and selecting such information from memory. The objective of this eye-tracking visual search study was to determine whether semantic expectancy mechanisms known to support object recognition in healthy adults are preserved in AD patients. Furthermore, as AD patients are often reported to be impaired in accessing information in extra-foveal vision, we investigated whether that was also the case in our study. Twenty AD patients and 20 age-matched controls searched for a target object among an array of distractors presented extra-foveally. The distractors were either semantically related or unrelated to the target (e.g., a car in an array with other vehicles or kitchen items). Results showed that semantically related objects were detected with more difficulty than semantically unrelated objects by both groups, but more markedly by the AD group. Participants looked earlier and for longer at the critical objects when these were semantically unrelated to the distractors. Our findings show that AD patients can process the semantics of objects and access it in extra-foveal vision. This suggests that their impairments in semantic processing may reflect difficulties in accessing semantic information rather than a generalised loss of semantic memory. |
Annabell Coors; Mohammed Aslam Imtiaz; Meta M. Boenniger; N. Ahmad Aziz; Ulrich Ettinger; Monique M. B. Breteler Associations of genetic liability for Alzheimer's disease with cognition and eye movements in a large, population-based cohort study Journal Article In: Translational Psychiatry, vol. 12, pp. 1–11, 2022. @article{Coors2022a, To identify cognitive measures that may be particularly sensitive to early cognitive decline in preclinical Alzheimer's disease (AD), we investigated the relation between genetic risk for AD and cognitive task performance in a large population-based cohort study. We measured performance on memory, processing speed, executive function, crystallized intelligence and eye movement tasks in 5182 participants of the Rhineland Study, aged 30 to 95 years. We quantified genetic risk for AD by creating three weighted polygenic risk scores (PRS) based on the genome-wide significant single-nucleotide polymorphisms coming from three different genetic association studies. We assessed the relation of AD PRS with cognitive performance using generalized linear models. Three PRS were associated with lower performance on the Corsi forward task, and two PRS were associated with a lower probability of correcting antisaccade errors, but none of these associations remained significant after correction for multiple testing. Associations between age and trail-making test A (TMT-A) performance were modified by AD genetic risk, with individuals at high genetic risk showing the strongest association. We conclude that no single measure of our cognitive test battery robustly captures genetic liability for AD as quantified by current PRS. However, Corsi forward performance and the probability of correcting antisaccade errors may represent promising candidates whose ability to capture genetic liability for AD should be investigated further. Additionally, our finding on TMT-A performance suggests that processing speed represents a sensitive marker of AD genetic risk in old age and supports the processing speed theory of age-related cognitive decline. |
Bing Dai; Kwang Meng Cham; Larry Allen Abel Perception of coherent motion in infantile nystagmus syndrome Journal Article In: Investigative Ophthalmology & Visual Science, vol. 63, no. 1, pp. 1–10, 2022. @article{Dai2022, PURPOSE. Research on infantile nystagmus syndrome (INS) and motion perception is limited. We investigated how individuals with INS perform coherent motion tasks. Particularly, we assessed how the null position affects their performance. METHODS. Subjects with INS and controls identified the direction of coherent motion stimuli (22 subjects with INS and 13 controls) in a two-alternative forced-choice design. For subjects with INS, testing was done at the null position and 15 degrees away from it. If there was no null, testing was done at primary gaze position and 15 degrees away from primary. For controls, testing was done at primary gaze position and 20 degrees away from primary. Horizontal and vertical motion coherence thresholds were determined. RESULTS. Subjects with INS showed significantly higher horizontal and vertical motion coherence thresholds compared with controls at both gaze positions (P < 0.001). Within the INS group, for 12 subjects with INS who had an identified null position, no differences in coherence thresholds were found between their null and 15 degrees away from it (P > 0.05). CONCLUSIONS. Coherent motion perception was impaired in subjects with INS. The null position did not significantly influence motion coherence thresholds for either horizontal or vertical motion. |
Kelly M. Dann; Aaron Veldre; Phillipa Hay; Stephen Touyz; Sally Andrews Assessing cognitive flexibility in anorexia nervosa using eye tracking: A registered report Journal Article In: International Journal of Eating Disorders, vol. 55, no. 10, pp. 1411–1417, 2022. @article{Dann2022, Objective: Cognitive flexibility research in anorexia nervosa (AN) has primarily focused on group differences between clinical and control participants, but research in the general population utilizing the mixed pro- anti-saccade flexibility task has demonstrated individual differences in trait anxiety are a determinant of switching performance, and switching impairments are more pronounced for keypress than saccadic (eye-movement) responses. The aim of the current research is to explore trait anxiety and differences in saccadic and keypress responding as potential determinants of performance on flexibility tasks in AN. Method: We will compare performance on the mixed pro- anti-saccade paradigm between female adult participants with a current diagnosis of AN and matched control participants, observing both saccadic and keypress responses while controlling for trait anxiety (State - Trait Anxiety Inventory) and spatial working memory (Corsi Block Tapping Test). Associations with eating disorder-related symptoms (Eating Disorder Examination Questionnaire), flexibility in everyday life (Eating Disorder Flexibility Index), and the Clinical Perfectionism Questionnaire will also be assessed. Results: Data which controls for individual differences in trait anxiety and assesses flexibility at both the task- and response-set level may be used to more accurately understand differences in performance on cognitive flexibility tasks by participants with AN. Discussion: Clarifying the effects of trait anxiety on flexibility, and differences between task- and response-set switching may advance our understanding of how cognitive flexibility relates to flexibility in everyday life and improve translation to therapeutic approaches. Public significance statement: This research will compare performance on a flexibility task between participants with anorexia nervosa (AN) and controls while observing their eye-movements to examine whether trait anxiety and type of response (eye-movement and keypress) are associated with performance. This data may improve our understanding of why participants with AN perform more poorly on cognitive flexibility tasks, and how poor cognitive flexibility relates to eating disorder-related issues with flexibility in everyday life. |
Bertrand Degos; Pierre Pouget; Marcus Missal From anticipation to impulsivity in Parkinson's disease Journal Article In: npj Parkinson's Disease, vol. 8, pp. 1–12, 2022. @article{Degos2022, Anticipatory actions require to keep track of elapsed time and inhibitory control. These cognitive functions could be impacted in Parkinson's disease (iPD). To test this hypothesis, a saccadic reaction time task was used where a visual warning stimulus (WS) predicted the occurrence of an imperative one (IS) appearing after a short delay. In the implicit condition, subjects were not informed about the duration of the delay, disfavoring anticipatory behavior but leaving inhibitory control unaltered. In the explicit condition, delay duration was cued. This should favor anticipatory behavior and perhaps alter inhibitory control. This hypothesis was tested in controls (N = 18) and age-matched iPD patients (N = 20; ON and OFF L-DOPA). We found that the latency distribution of saccades before the IS was bimodal. The 1st mode weakly depended on temporal information and was more prominent in iPD. Saccades in this mode were premature and could result of a lack of inhibition. The 2nd mode covaried with cued duration suggesting that these movements were genuine anticipatory saccades. The explicit condition increased the probability of anticipatory saccades before the IS in controls and iPDON but not iPDOFF patients. Furthermore, in iPD patients the probability of sequences of 1st mode premature responses increased. In conclusion, the triggering of a premature saccade or the initiation of a controlled anticipatory one could be conceptualized as the output of two independent stochastic processes. Altered time perception and increased motor impulsivity could alter the balance between these two processes in favor of the latter in iPD, particularly OFF L-Dopa. |
Daniel G. Dillon; Amit Lazarov; Sarah Dolan; Yair Bar-Haim; Diego A. Pizzagalli; Franklin R. Schneier Fast evidence accumulation in social anxiety disorder enhances decision making in a probabilistic reward task Journal Article In: Emotion, vol. 22, no. 1, pp. 1–18, 2022. @article{Dillon2022, Choices and response times in two-alternative decision-making tasks can be modeled by assuming that individuals steadily accrue evidence in favor of each alternative until a response boundary for one of them is crossed, at which point that alternative is chosen. Prior studies have reported that evidence accumulation during decision-making tasks takes longer in adults with psychopathology than in healthy controls, indicating that slow evidence accumulation may be transdiagnostic. However, few studies have examined perceptual decision making in anxiety disorders, where hypervigilance might enhance performance. Therefore, this study used the Hierarchical Drift Diffusion model to investigate evidence accumulation in adults with social anxiety disorder (SAD) and healthy controls as they performed a probabilistic reward task (PRT), in which social rewards were delivered for correct perceptual judgments. Adults with SAD completed the PRT before and after gaze-contingent music reward therapy (GCMRT), which trains attention allocation and has shown efficacy for SAD. Healthy controls also completed the PRT twice. Results revealed excellent performance in adults with SAD, especially after GCMRT: relative to controls, they showed faster evidence accumulation, better discriminability, and earned more rewards. These data highlight a positive effect of attention training on performance in anxious adults and show how a behavioral trait that is typically problematic-hypervigilance in SAD-can nevertheless confer advantages in certain contexts. The data also indicate that, in contrast to other forms of psychopathology, SAD is not characterized by slow evidence accumulation, at least in the context of the social PRT. |
2021 |
Sarah Chabal; Sayuri Hayakawa; Viorica Marian How a picture becomes a word: Individual differences in the development of language-mediated visual search Journal Article In: Cognitive Research: Principles and Implications, vol. 6, no. 2, pp. 1–10, 2021. @article{Chabal2021, Over the course of our lifetimes, we accumulate extensive experience associating the things that we see with the words we have learned to describe them. As a result, adults engaged in a visual search task will often look at items with labels that share phonological features with the target object, demonstrating that language can become activated even in non-linguistic contexts. This highly interactive cognitive system is the culmination of our linguistic and visual experiences—and yet, our understanding of how the relationship between language and vision develops remains limited. The present study explores the developmental trajectory of language-mediated visual search by examining whether children can be distracted by linguistic competitors during a non-linguistic visual search task. Though less robust compared to what has been previously observed with adults, we find evidence of phonological competition in children as young as 8 years old. Furthermore, the extent of language activation is predicted by individual differences in linguistic, visual, and domain-general cognitive abilities, with the greatest phonological competition observed among children with strong language abilities combined with weaker visual memory and inhibitory control. We propose that linguistic expertise is fundamental to the development of language-mediated visual search, but that the rate and degree of automatic language activation depends on interactions among a broader network of cognitive abilities. |
Jasmine R. Aziz; Samantha R. Good; Raymond M. Klein; Gail A. Eskes Role of aging and working memory in performance on a naturalistic visual search task Journal Article In: Cortex, vol. 136, pp. 28–40, 2021. @article{Aziz2021, Studying age-related changes in working memory (WM) and visual search can provide insights into mechanisms of visuospatial attention. In visual search, WM is used to remember previously inspected objects/locations and to maintain a mental representation of the target to guide the search. We sought to extend this work, using aging as a case of reduced WM capacity. The present study tested whether various domains of WM would predict visual search performance in both young (n = 47; aged 18–35 yrs) and older (n = 48; aged 55–78) adults. Participants completed executive and domain-specific WM measures, and a naturalistic visual search task with (single) feature and triple-conjunction (three-feature) search conditions. We also varied the WM load requirements of the search task by manipulating whether a reference picture of the target (i.e., target template) was displayed during the search, or whether participants needed to search from memory. In both age groups, participants with better visuospatial executive WM were faster to locate complex search targets. Working memory storage capacity predicted search performance regardless of target complexity; however, visuospatial storage capacity was more predictive for young adults, whereas verbal storage capacity was more predictive for older adults. Displaying a target template during search diminished the involvement of WM in search performance, but this effect was primarily observed in young adults. Age-specific interactions between WM and visual search abilities are discussed in the context of mechanisms of visuospatial attention and how they may vary across the lifespan. |
Aaron Veldre; Roslyn Wong; Sally Andrews Reading proficiency predicts the extent of the right, but not left, perceptual span in older readers Journal Article In: Attention, Perception, and Psychophysics, vol. 83, no. 1, pp. 18–26, 2021. @article{Veldre2021, The gaze-contingent moving-window paradigm was used to assess the size and symmetry of the perceptual span in older readers. The eye movements of 49 cognitively intact older adults (60–88 years of age) were recorded as they read sentences varying in difficulty, and the availability of letter information to the right and left of fixation was manipulated. To reconcile discrepancies in previous estimates of the perceptual span in older readers, individual differences in written language proficiency were assessed with tests of vocabulary, reading comprehension, reading speed, spelling ability, and print exposure. The results revealed that higher proficiency older adults extracted information up to 15 letter spaces to the right of fixation, while lower proficiency readers showed no additional benefit beyond 9 letters to the right. However, all readers showed improvements to reading with the availability of up to 9 letters to the left—confirming previous evidence of reduced perceptual span asymmetry in older readers. The findings raise questions about whether the source of age-related changes in parafoveal processing lies in the adoption of a risky reading strategy involving an increased propensity to both guess upcoming words and make corrective regressions. |
Mikael Rubin; Michael J. Telch Pupillary response to affective voices: Physiological responsivity and posttraumatic stress disorder Journal Article In: Journal of Traumatic Stress, vol. 34, no. 1, pp. 182–189, 2021. @article{Rubin2021a, Posttraumatic stress disorder (PTSD) is related to dysfunctional emotional processing, thus motivating the search for physiological indices that can elucidate this process. Toward this aim, we compared pupillary response patterns in response to angry and fearful auditory stimuli among 99 adults, some with PTSD (n = 14), some trauma-exposed without PTSD (TE; n = 53), and some with no history of trauma exposure (CON; n = 32). We hypothesized that individuals with PTSD would show more pupillary response to angry and fearful auditory stimuli compared to those in the TE and CON groups. Among participants who had experienced a traumatic event, we explored the association between PTSD symptoms and pupillary response; contrary to our prediction, individuals with PTSD displayed the least pupillary response to fearful auditory stimuli compared those in the TE |
Alessandro Piras; Matthew A. Timmis; Aurelio Trofè; Milena Raffi Visual strategies underpinning the spatiotemporal demands during visuomotor tasks in predicting ball direction Journal Article In: Journal of Sport and Exercise Psychology, vol. 43, no. 6, pp. 514–523, 2021. @article{Piras2021, We investigated gaze behavior of expert goalkeepers during the prediction of penalty kicks in different spatiotemporal constraints: penalties taken from 11 and 6 m. From 11 m, goalkeepers were more successful in predicting ball direction, with longer movement time initiation and a visual strategy with more fixations and greater saccade rates than penalties from 6 m, where they exhibited fewer fixations with higher microsaccade rates. As long as the opponent's distance is large and time pressure low, gaze can be frequently shifted between the kicker's body and the ball, due to the low cost of saccades. Conversely, when the objects are close, there is increased reliance on foveal and parafoveal information. In conclusion, when the spatiotemporal constraint is less severe, goalkeepers adopt a visual strategy with more fixations and small saccades. When the spatiotemporal constraint is more severe, they rely on peripheral vision to monitor kickers' movements through the use of microsaccades. |
Ella Podvalny; Leana E. King; Biyu J. He Spectral signature and behavioral consequence of spontaneous shifts of pupil-linked arousal in human Journal Article In: eLife, vol. 10, pp. e68265, 2021. @article{Podvalny2021, Arousal levels perpetually rise and fall spontaneously. How markers of arousal—pupil size and frequency content of brain activity—relate to each other and influence behavior in humans is poorly understood. We simultaneously monitored magnetoencephalography and pupil in healthy volunteers at rest and during a visual perceptual decision-making task. Spontaneously varying pupil size correlates with power of brain activity in most frequency bands across large-scale resting-state cortical networks. Pupil size recorded at prestimulus baseline correlates with subsequent shifts in detection bias (c) and sensitivity (d'). When dissociated from pupil-linked state, prestimulus spectral power of resting state networks still predicts perceptual behavior. Fast spontaneous pupil constriction and dilation correlate with large-scale brain activity as well but not perceptual behavior. Our results illuminate the relation between central and peripheral arousal markers and their respective roles in human perceptual decision-making. |
Dorothee Pöhlchen; Marthe Priouret; Miriam S. Kraft; Florian P. Binder; Deniz A. Gürsel; Götz Berberich; Kathrin Koch; Victor I. Spoormaker In: Frontiers in Psychiatry, vol. 12, pp. 730742, 2021. @article{Poehlchen2021, Obsessive-compulsive disorder (OCD) is characterized by recurrent, persistent thoughts and repetitive behaviors causing stress and anxiety. In the associative learning model of OCD, mechanisms of fear extinction are supposed to partly underlie symptom development, maintenance and treatment of OCD, proposing that OCD patients suffer from rigid memory associations and inhibitory learning deficits. To test these assumptions, previous studies have used skin conductance and subjective ratings as readouts in fear conditioning paradigms, finding impaired fear extinction learning, impaired fear extinction recall or no differences between individuals with OCD and healthy controls. Against this heterogeneous background, we tested fear acquisition and extinction in 37 OCD patients and 56 healthy controls, employing skin conductance as well as pupillometry and startle electromyography. Extinction recall was also included in a subsample. We did not observe differences between groups in any of the task phases, except a trend toward higher startle amplitudes during extinction for OCD. Overall, sensitive readouts such as pupillometry and startle responses did not provide evidence for moderate-to-large inhibitory learning deficits using classical fear conditioning, challenging the assumption of generically impaired extinction learning and memory in OCD. |
Brendan L. Portengen; Carlien Roelofzen; Giorgio L. Porro; Saskia M. Imhof; Alessio Fracasso; Marnix Naber Blind spot and visual field anisotropy detection with flicker pupil perimetry across brightness and task variations Journal Article In: Vision Research, vol. 178, pp. 79–85, 2021. @article{Portengen2021, The pupil can be used as an objective measure for testing sensitivities across the visual field (pupil perimetry; PP). The recently developed gaze-contingent flicker PP (gcFPP) is a promising novel form of PP, with improved sensitivity due to retinotopically stable and repeated flickering stimulations, in a short time span. As a diagnostic tool gcFPP has not yet been benchmarked in healthy individuals. The main aims of the current study were to investigate whether gcFPP has the sensitivity to detect the blind spot, and upper versus lower visual field differences that were found before in previous studies. An additional aim was to test for the effects of attentional requirements and background luminance. A total of thirty individuals were tested with gcFPP across two separate experiments. The results showed that pupil oscillation amplitudes were smaller for stimuli presented inside as compared to outside the blind spot. Amplitudes also decreased as a function of eccentricity (i.e., distance to fixation) and were larger for upper as compared to lower visual fields. We measured the strongest and most sensitive pupil responses to stimuli presented on dark- and mid-gray backgrounds, and when observers covertly focused their attention to the flickering stimulus. GcFPP thus evokes pupil responses that are sensitive enough to detect local, and global differences in pupil sensitivity. The findings further encourage (1) the use of a gray background to prevent straylight without affecting gcFPPs sensitivity and (2) the use of an attention task to enhance pupil sensitivity. |
Hamed Rahimi-Nasrabadi; Jianzhong Jin; Reece Mazade; Carmen Pons; Sohrab Najafian; Jose-Manuel Alonso Image luminance changes contrast sensitivity in visual cortex Journal Article In: Cell Reports, vol. 34, no. 5, pp. 1–21, 2021. @article{RahimiNasrabadi2021, Accurate measures of contrast sensitivity are important for evaluating visual disease progression and for navigation safety. Previous measures suggested that cortical contrast sensitivity was constant across widely different luminance ranges experienced indoors and outdoors. Against this notion, here, we show that luminance range changes contrast sensitivity in both cat and human cortex, and the changes are different for dark and light stimuli. As luminance range increases, contrast sensitivity increases more within cortical pathways signaling lights than those signaling darks. Conversely, when the luminance range is constant, light-dark differences in contrast sensitivity remain relatively constant even if background luminance changes. We show that a Naka-Rushton function modified to include luminance range and light-dark polarity accurately replicates both the statistics of light-dark features in natural scenes and the cortical responses to multiple combinations of contrast and luminance. We conclude that differences in light-dark contrast increase with luminance range and are largest in bright environments. |
Matti Rantanen; Jarkko Hautala; Otto Loberg; Jaakko Nuorva; Jari K. Hietanen; Lauri Nummenmaa; Piia Astikainen Attentional bias towards interpersonal aggression in depression - An eye movement study Journal Article In: Scandinavian Journal of Psychology, vol. 62, no. 5, pp. 639–647, 2021. @article{Rantanen2021, Depressed individuals exhibit an attentional bias towards mood-congruent stimuli, yet evidence for biased processing of threat-related information in human interaction remains scarce. Here, we tested whether an attentional bias towards interpersonally aggressive pictures over interpersonally neutral pictures could be observed to a greater extent in depressed participants than in control participants. Eye movements were recorded while the participants freely viewed visually matched interpersonally aggressive and neutral pictures, which were presented in pairs. Across the groups, participants spent more time looking at neutral pictures than at aggressive pictures, probably reflecting avoidance behavior. When the participants could anticipate the stimulus valence, depressed participants – but not controls – showed an early attentional bias towards interpersonally aggressive pictures, as indexed by their longer first fixation durations on aggressive pictures than on neutral pictures. Our results thus preliminarily suggest both an early attentional bias towards interpersonal aggression, which is present, in depressed participants, also when aggression contents are anticipated, and a later attentional avoidance of aggression. The early depression-related bias in information processing may have maladaptive effects on the way depressed individuals perceive and function in social interaction and can, therefore, maintain depressed mood. |
Ryan V. Raut; Abraham Z. Snyder; Anish Mitra; Dov Yellin; Naotaka Fujii; Rafael Malach; Marcus E. Raichle Global waves synchronize the brain's functional systems with fluctuating arousal Journal Article In: Science Advances, vol. 7, no. 30, pp. eabf2709, 2021. @article{Raut2021, We propose and empirically support a parsimonious account of intrinsic, brain-wide spatiotemporal organization arising from traveling waves linked to arousal. We hypothesize that these waves are the predominant physiological process reflected in spontaneous functional magnetic resonance imaging (fMRI) signal fluctuations. The correlation structure ("functional connectivity") of these fluctuations recapitulates the large-scale functional organization of the brain. However, a unifying physiological account of this structure has so far been lacking. Here, using fMRI in humans, we show that ongoing arousal fluctuations are associated with global waves of activity that slowly propagate in parallel throughout the neocortex, thalamus, striatum, and cerebellum. We show that these waves can parsimoniously account for many features of spontaneous fMRI signal fluctuations, including topographically organized functional connectivity. Last, we demonstrate similar, cortex-wide propagation of neural activity measured with electrocorticography in macaques. These findings suggest that traveling waves spatiotemporally pattern brain-wide excitability in relation to arousal. |
Gabrielle E. Reimann; Catherine Walsh; Kelsey D. Csumitta; Patrick McClure; Francisco Pereira; Alex Martin; Michal Ramot Gauging facial feature viewing preference as a stable individual trait in autism spectrum disorder Journal Article In: Autism Research, vol. 14, no. 8, pp. 1670–1683, 2021. @article{Reimann2021, Eye tracking provides insights into social processing deficits in autism spectrum disorder (ASD), especially in conjunction with dynamic, naturalistic free-viewing stimuli. However, the question remains whether gaze characteristics, such as preference for specific facial features, can be considered a stable individual trait, particularly in those with ASD. If so, how much data are needed for consistent estimations? To address these questions, we assessed the stability and robustness of gaze preference for facial features as incremental amounts of movie data were introduced for analysis. We trained an artificial neural network to create an object-based segmentation of naturalistic movie clips (14 s each, 7410 frames total). Thirty-three high-functioning individuals with ASD and 36 age- and IQ-equated typically developing individuals (age range: 12–30 years) viewed 22 Hollywood movie clips, each depicting a social interaction. As we evaluated combinations of one, three, five, eight, and 11 movie clips, gaze dwell times on core facial features became increasingly stable at within-subject, within-group, and between-group levels. Using a number of movie clips deemed sufficient by our analysis, we found that individuals with ASD displayed significantly less face-centered gaze (centralized on the nose; p < 0.001) but did not significantly differ from typically developing participants in eye or mouth looking times. Our findings validate gaze preference for specific facial features as a stable individual trait and highlight the possibility of misinterpretation with insufficient data. Additionally, we propose the use of a machine learning approach to stimuli segmentation to quickly and flexibly prepare dynamic stimuli for analysis. Lay Summary: Using a data-driven approach to segmenting movie stimuli, we examined varying amounts of data to assess the stability of social gaze in individuals with autism spectrum disorder (ASD). We found a reduction in social fixations in participants with ASD, driven by decreased attention to the center of the face. Our findings further support the validity of gaze preference for face features as a stable individual trait when sufficient data are used. |
Giulietta M. Riboldi; John Martone; John-Ross Rizzo; Todd E. Hudson; Janet C. Rucker; Steven J. Frucht Looking “cherry red spot myoclonus” in the eyes: clinical phenotype, treatment response, and eye movements in sialidosis type 1 Journal Article In: Tremor and Other Hyperkinetic Movements, vol. 11, no. 1, pp. 53, 2021. @article{Riboldi2021, Sialidosis type 1 is a rare lysosomal storage disorder caused by mutations of the neura-minidase gene. Specific features suggesting this condition include myoclonus, ataxia and macular cherry-red spots. However, phenotypic variability exists. Here, we present detailed clinical and video description of three patients with this rare condition. We also provide an in?depth characterization of eye movement abnormalities, as an additional tool to investigate pathophysiological mechanisms and to facilitate diagnosis. In our patients, despite phenotypic differences, eye movement deficits largely localized to the cerebellum. |
Samy Rima; Michael C. Schmid Reading specific small saccades predict individual phonemic awareness and reading speed Journal Article In: Frontiers in Neuroscience, vol. 15, pp. 663242, 2021. @article{Rima2021, Small fixational eye-movements are a fundamental aspect of vision and thought to reflect fine shifts in covert attention during active viewing. While the perceptual benefits of these small eye movements have been demonstrated during a wide range of experimental tasks including during free viewing, their function during reading remains surprisingly unclear. Previous research demonstrated that readers with increased microsaccade rates displayed longer reading speeds. To what extent increased fixational eye movements are, however, specific to reading and might be indicative of reading skill deficits remains, however, unknown. To address this topic, we compared the eye movement scan paths of 13 neurotypical individuals and 13 subjects diagnosed with developmental dyslexia during short story reading and free viewing of natural scenes. We found that during reading only, dyslexics tended to display small eye movements more frequently compared to neurotypicals, though this effect was not significant at the population level, as it could also occur in slow readers not diagnosed as dyslexics. In line with previous research, neurotypical readers had twice as many regressive compared to progressive microsaccades, which did not occur during free viewing. In contrast, dyslexics showed similar amounts of regressive and progressive small fixational eye movements during both reading and free viewing. We also found that participants with smaller fixational saccades from both neurotypical and dyslexic samples displayed reduced reading speeds and lower scores during independent tests of reading skill. Slower readers also displayed greater variability in the landing points and temporal occurrence of their fixational saccades. Both the rate and spatio-temporal variability of fixational saccades were associated with lower phonemic awareness scores. As none of the observed differences between dyslexics and neurotypical readers occurred during control experiments with free viewing, the reported effects appear to be directly related to reading. In summary, our results highlight the predictive value of small saccades for reading skill, but not necessarily for developmental dyslexia. |
Miriam Rivero-Contreras; Paul E. Engelhardt; David Saldaña An experimental eye-tracking study of text adaptation for readers with dyslexia: Effects of visual support and word frequency Journal Article In: Annals of Dyslexia, vol. 71, no. 1, pp. 170–187, 2021. @article{RiveroContreras2021, Easy-to-read guidelines recommend visual support and lexical simplification to facilitate text processing, but few empirical studies confirm a positive effect from these recommendations in individuals with dyslexia. This study examined the influence of the visual support and lexical simplification on sentence processing through eye movements at both the text- and word-level, and the differences between readers with and without dyslexia. Furthermore, we explored the influence of reading experience and vocabulary, as control variables. We tested 20 young adults with dyslexia and 20 chronological age-matched controls. Participants read 60 sentences in total. Half the sentences contained an image and the other half did not, and half contained a low-frequency word and half a high-frequency word. Results showed that visual support and lexical simplification facilitated sentence processing, potentially by jointly facilitating lexical semantic access. We also found that participants with lower print exposure and lower vocabulary benefited more from word-level lexical simplification. We conclude that both adaptations could benefit readers with low print exposure and smaller vocabularies, and therefore, to many dyslexic readers who show these characteristics. |
William Rosengren; Marcus Nyström; Björn Hammar; Martin Stridh Waveform characterisation and comparison of nystagmus eye-tracking signals Journal Article In: Physiological Measurement, vol. 42, pp. 015004, 2021. @article{Rosengren2021, Objective: Pathological nystagmus is a symptom of oculomotor disease where the eyes oscillate involuntarily. The underlying cause of the nystagmus and the characteristics of the oscillatory eye movements are patient specific. An important part of clinical assessment in nystagmus patients is therefore to characterise different recorded eye-tracking signals, i.e., waveforms. Approach: A method for characterisation of the nystagmus waveform morphology is proposed. The method extracts local morphologic characteristics based on a sinusoidal model, and clusters these into a description of the complete signal. The clusters are used to characterise and compare recordings within and between patients and tasks. New metrics are proposed that can measure waveform similarity at different scales; from short signal segments up to entire signals, both within and between patients. Main results: The results show that the proposed method robustly can find the most prominent nystagmus waveforms in a recording. The method accurately identifies different eye movement patterns within and between patients and across different tasks. Significance: In conclusion, by allowing characterisation and comparison of nystagmus waveform patterns, the proposed method opens up for investigation and identification of the underlying condition in the individual patient, and for quantifying eye movements during tasks. |
Kathryn M. Rothenhoefer; Tao Hong; Aydin Alikaya; William R. Stauffer Rare rewards amplify dopamine responses Journal Article In: Nature Neuroscience, vol. 24, no. 4, pp. 465–469, 2021. @article{Rothenhoefer2021, Dopamine prediction error responses are essential components of universal learning mechanisms. However, it is unknown whether individual dopamine neurons reflect the shape of reward distributions. Here, we used symmetrical distributions with differently weighted tails to investigate how the frequency of rewards and reward prediction errors influence dopamine signals. Rare rewards amplified dopamine responses, even when conventional prediction errors were identical, indicating a mechanism for learning the complexities of real-world incentives. |
Lucy L. Russell; Caroline V. Greaves; Rhian S. Convery; Martina Bocchetta; Jason D. Warren; Diego Kaski; Jonathan D. Rohrer Eye movements in frontotemporal dementia: Abnormalities of fixation, saccades and anti‐saccades Journal Article In: Alzheimer's & Dementia: Translational Research & Clinical Interventions, vol. 7, no. 1, pp. e12218, 2021. @article{Russell2021, Introduction: Oculomotor function has not been systematically studied in frontotemporal dementia (FTD) and yet may offer a simple target to monitor disease activity. Methods: We assessed fixation stability, smooth pursuit, pro-saccades, and anti- saccades using the Eyelink 1000-plus eye-tracker in 19 individuals with behavioral variantFTD (bvFTD) and22 controls.Neuroanatomical correlates were assessed using a region of interest magnetic resonance imaging (MRI) analysis. Results: Measures of fixation stability were impaired in the bvFTD group compared with controls. However, performance did not differ from controls in the pro-saccade tasks except in the vertical overlap condition. The bvFTD group performed worse in the anti-saccade task,which correlated strongly with executive function. Neural corre- lates included the orbitofrontal and ventromedial prefrontal cortices and striatum for fixation stability, and the dorsolateral prefrontal and parietal cortices and striatum for anti-saccades. Discussion: Overall, oculomotor function is abnormal in bvFTD, with performance likely related to impairment of inhibitory control and executive dysfunction. |
Lucy L. Russell; Caroline V. Greaves; Rhian S. Convery; Jennifer Nicholas; Jason D. Warren; Diego Kaski; Jonathan D. Rohrer Novel instructionless eye tracking tasks identify emotion recognition deficits in frontotemporal dementia Journal Article In: Alzheimer's Research and Therapy, vol. 13, pp. 39, 2021. @article{Russell2021a, Background: Current tasks measuring social cognition are usually ‘pen and paper' tasks, have ceiling effects and include complicated test instructions that may be difficult to understand for those with cognitive impairment. We therefore aimed to develop a set of simple, instructionless, quantitative, tasks of emotion recognition using the methodology of eye tracking, with the subsequent aim of assessing their utility in individuals with behavioural variant frontotemporal dementia (bvFTD). Methods: Using the Eyelink 1000 Plus eye tracker, 18 bvFTD and 22 controls completed tasks of simple and complex emotion recognition that involved viewing four images (one target face (simple) or pair of eyes (complex) and the others non-target) followed by a target emotion word and lastly the original four images alongside the emotion word. A dwell time change score was then calculated as the main outcome measure by subtracting the percentage dwell time for the target image before the emotion word appeared away from the percentage dwell time for the target image after the emotion word appeared. All participants also underwent a standard cognitive battery and volumetric T1-weighted magnetic resonance imaging. Results: Analysis using a mixed effects model showed that the average (standard deviation) mean dwell time change score in the target interest area was 35 (27)% for the control group compared with only 4 (18)% for the bvFTD group (p < 0.05) for the simple emotion recognition task, and 15 (26)% for the control group compared with only 2 (18)% for the bvFTD group (p < 0.05) for the complex emotion recognition task. Worse performance in the bvFTD group correlated with atrophy in the right ventromedial prefrontal and orbitofrontal cortices, brain regions previously implicated in social cognition. Conclusions: In summary, eye tracking is a viable tool for assessing social cognition in individuals with bvFTD, being well-tolerated and able to overcome some of the problems associated with standard psychometric tasks. |
Anthony J. Ryals; Megan E. Kelly; Anne M. Cleary Increased pupil dilation during tip-of-the-tongue states Journal Article In: Consciousness and Cognition, vol. 92, pp. 103152, 2021. @article{Ryals2021, Tip-of-the-tongue states (TOTs) are feelings of impending word retrieval success during a current failure to retrieve a target word. Though much is known and understood about TOT states from decades of research, research on potential psychophysiological correlates of the TOT state is still in its infancy, and existing studies point toward the involvement of neural processes that are associated with enhanced attention, motivation, and information-seeking. In the present study, we demonstrate that, during instances of target retrieval failure, TOT states are associated with greater pupillary dilation (i.e., autonomic arousal) in 91% of our sample. This is the first study to demonstrate a pupillometric correlate of the TOT experience, and this finding provides an important step toward understanding emotional attributes associated with TOT states. Mean pupil dilation also increased such that instances of target identification failure that were unaccompanied by TOT states < instances in which TOTs occurred < instances of target identification success. It is possible that TOTs reflect an intermediary state between complete target retrieval failure and full target retrieval. |
Giulia C. Salgari; Geoffrey F. Potts; Joseph Schmidt; Chi C. Chan; Christopher C. Spencer; Jeffrey S. Bedwell Event-related potentials to rare visual targets and negative symptom severity in a transdiagnostic psychiatric sample Journal Article In: Clinical Neurophysiology, vol. 132, no. 7, pp. 1526–1536, 2021. @article{Salgari2021, Objectives: Negative psychiatric symptoms are often resistant to treatments, regardless of the disorder in which they appear. One model for a cause of negative symptoms is impairment in higher-order cognition. The current study examined how particular bottom-up and top-down mechanisms of selective attention relate to severity of negative symptoms across a transdiagnostic psychiatric sample. Methods: The sample consisted of 130 participants: 25 schizophrenia-spectrum disorders, 26 bipolar disorders, 18 unipolar depression, and 61 nonpsychiatric controls. The relationships between attentional event-related potentials following rare visual targets (i.e., N1, N2b, P2a, and P3b) and severity of the negative symptom domains of anhedonia, avolition, and blunted affect were evaluated using frequentist and Bayesian analyses. Results: P3b and N2b mean amplitudes were inversely related to the Positive and Negative Syndrome Scale-Negative Symptom Factor severity score across the entire sample. Subsequent regression analyses showed a significant negative transdiagnostic relationship between P3b amplitude and blunted affect severity. Conclusions: Results indicate that negative symptoms, and particularly blunted affect, may have a stronger association with deficits in top-down mechanisms of selective attention. Significance: This suggests that people with greater severity of blunted affect, independent of diagnosis, do not allocate sufficient cognitive resources when engaging in activities requiring selective attention. |
Musa Basseer Sami; Luciano Annibale; Aisling O'Neill; Tracy Collier; Chidimma Onyejiaka; Savitha Eranti; Debasis Das; Marlene Kelbrick; Philip McGuire; Steve C. R. Williams; Anas Rana; Ulrich Ettinger; Sagnik Bhattacharyya Eye movements in patients in early psychosis with and without a history of cannabis use Journal Article In: npj Schizophrenia, vol. 7, pp. 24, 2021. @article{Sami2021, It is unclear whether early psychosis in the context of cannabis use is different from psychosis without cannabis. We investigated this issue by examining whether abnormalities in oculomotor control differ between patients with psychosis with and without a history of cannabis use. We studied four groups: patients in the early phase of psychosis with a history of cannabis use (EPC; n = 28); patients in the early phase of psychosis without (EPNC; n = 25); controls with a history of cannabis use (HCC; n = 16); and controls without (HCNC; n = 22). We studied smooth pursuit eye movements using a stimulus with sinusoidal waveform at three target frequencies (0.2, 0.4 and 0.6 Hz). Participants also performed 40 antisaccade trials. There were no differences between the EPC and EPNC groups in diagnosis, symptom severity or level of functioning. We found evidence for a cannabis effect (χ2 = 23.14, p < 0.001), patient effect (χ2 = 4.84 |
J. A. Elshout; D. P. Bergsma; A. V. Berg; K. V. Haak Functional MRI of visual cortex predicts training-induced recovery in stroke patients with homonymous visual field defects Journal Article In: NeuroImage: Clinical, vol. 31, pp. 102703, 2021. @article{Elshout2021, Post-chiasmatic damage to the visual system leads to homonymous visual field defects (HVDs), which can severely interfere with daily life activities. Visual Restitution Training (VRT) can recover parts of the affected visual field in patients with chronic HVDs, but training outcome is variable. An untested hypothesis suggests that training potential may be largest in regions with ‘neural reserve', where cortical responses to visual stimulation do not lead to visual awareness as assessed by Humphrey perimetry—a standard behavioural visual field test. Here, we tested this hypothesis in a sample of twenty-seven hemianopic stroke patients, who participated in an assiduous 80-hour VRT program. For each patient, we collected Humphrey perimetry and wide-field fMRI-based retinotopic mapping data prior to training. In addition, we used Goal Attainment Scaling to assess whether personal activities in daily living improved. After training, we assessed with a second Humphrey perimetry measurement whether the visual field was improved and evaluated which personal goals were attained. Confirming the hypothesis, we found significantly larger improvements of visual sensitivity at field locations with neural reserve. These visual field improvements implicated both regions in primary visual cortex and higher order visual areas. In addition, improvement in daily life activities correlated with the extent of visual field enlargement. Our findings are an important step toward understanding the mechanisms of visual restitution as well as predicting training efficacy in stroke patients with chronic hemianopia. |
Joris A. Elshout; Tanja C. W. Nijboer; Stefan Van der Stigchel Impaired pre-saccadic shifts of attention in neglect patients Journal Article In: Cortex, vol. 142, pp. 213–220, 2021. @article{Elshout2021a, Every saccade is generally preceded by a mandatory shift of attention to the saccade endpoint, allowing us to process visual information more effectively. Whether this ‘pre-saccadic shift of attention' is still intact in hemispatial neglect is unknown. Whereas neglect patients exhibit lateralized impairments of attention and often show impaired saccadic behaviour, it is not yet clear how the pre-saccadic shift of attention is affected during accurately executed eye movements. In this study, we used a gaze contingent visual discrimination task, in which neglect patients had to discriminate a probe presented before saccade onset. Results revealed an imbalance in discrimination performance between the two hemifields with poor performance to probes in the contralesional compared to the ipsilesional hemifield when accounting for saccadic impairments. These results suggest that attention and eye movements are both unique impairments of neglect patients. We hypothesize that the impaired pre-saccadic shift of attention could be one of the key problems of neglect and might underlie other spatial and non-spatial deficits often reported in neglect patients. |
Joris A. Elshout; Stefan Van der Stigchel; Tanja C. W. Nijboer Congruent movement training as a rehabilitation method to ameliorate symptoms of neglect–proof of concept Journal Article In: Cortex, vol. 142, pp. 84–93, 2021. @article{Elshout2021b, Stroke patients with visuospatial neglect (VSN) have difficulties responding to visual information located in the contralesional hemifield, affecting many daily life activities (ADL) such as eating, reading and mobility. Visual Scanning Therapy (VST) is widely used in clinical practice to ameliorate symptoms of VSN. Yet, not all patients benefit from this training and many training sessions are needed in order to achieve stable results. One potentially promising improvement to the VST is based on the theory that different effectors of the motor systems (e.g., eyes, hands) independently allocate attention during the programming of the movement (i.e., Pre Motor Theory of Attention (PMT)). Here, we studied this direct implementation of the PMT and tested whether a congruent movement training (CMT: congruent -i.e., executed at the same time to the same location-eye and pointing movements) is more effective to attenuate symptoms of neglect compared to VST. This study can be seen as a proof of concept. Attenuation of neglect symptoms was found in the CMT group after just 5 h of training in the subacute phase of neglect. In contrast, no training effects were found in the VST group. These findings indicate the potential of CMT which is a minimal –yet crucial-upgrade of the standard VST protocol that can be easily implemented in the clinic. |
Berkeley K. Fahrenthold; Matthew R. Cavanaugh; Subin Jang; Allison J. Murphy; Sara Ajina; Holly Bridge; Krystel R. Huxlin Optic tract shrinkage limits visual restoration after occipital stroke Journal Article In: Stroke, vol. 52, pp. 3642–3650, 2021. @article{Fahrenthold2021, BACKGROUND AND PURPOSE: Damage to the adult primary visual cortex (V1) causes vision loss in the contralateral visual hemifield, initiating a process of trans-synaptic retrograde degeneration. The present study examined functional implications of this process, asking if degeneration impacted the amount of visual recovery attainable from visual restoration training in chronic patients, and if restoration training impacted optic tract (OT) shrinkage. METHODS: Magnetic resonance imaging was used to measure OT volumes bilaterally in 36 patients with unilateral occipital stroke. From OT volumes, we computed laterality indices (LI), estimating the stroke-induced OT shrinkage in each case. A subset of these chronic patients (n=14, 13±6 months poststroke) underwent an average of nearly 1 year of daily visual restoration training, which repeatedly stimulated vision in their blind field. The amount of visual field recovery was quantified using Humphrey perimetry, and post training magnetic resonance imaging was used to assess the impact of training on OT shrinkage. RESULTS: OT LI was correlated with time since stroke: It was close to 0 (no measurable OT shrinkage) in subacute participants (<6 months poststroke) while chronic participants (>6 months poststroke) exhibited LI >0, but with significant variability. Visual training did not systematically alter LI, but chronic patients with baseline LI≈0 (no OT shrinkage) exhibited greater visual field recovery than those with LI>0. CONCLUSIONS: Unilateral OT shrinkage becomes detectable with magnetic resonance imaging by ≈7 months poststroke, albeit with significant interindividual variability. Although visual restoration training did not alter the amount of degeneration already sustained, OT shrinkage appeared to serve as a biomarker of the potential for training-induced visual recovery in chronic cortically blind patients. |
George D. Farmer; Paula Smith; Simon Baron-Cohen; William J. Skylark The effect of autism on information sampling during decision-making: An eye-tracking study Journal Article In: Judgment and Decision Making, vol. 16, no. 3, pp. 614–637, 2021. @article{Farmer2021, Recent research has highlighted a tendency for more rational and deliberative decision-making in individuals with autism. We tested this hypothesis by using eye-tracking to investigate the information processing strategies that underpin multiattribute choice in a sample of adults diagnosed with autism spectrum condition. We found that, as the number of attributes defining each option increased, autistic decision-makers were speedier, examined less of the available information, and spent a greater proportion of their time examining the option they eventually chose. Rather than indicating a more deliberative style, our results are consistent with a tendency for individuals with autism to narrow down the decision-space more quickly than does the neurotypical population. |
Gerardo Fernández; Mario A. Parra Oculomotor behaviors and integrative memory functions in the Alzheimer's Clinical Syndrome Journal Article In: Journal of Alzheimer's Disease, vol. 82, no. 3, pp. 1033–1044, 2021. @article{Fernandez2021, Background: Biological information drawn from eye-tracking metrics is providing evidence regarding drivers of cognitive decline in Alzheimer's disease. In particular, pupil size has proved useful to investigate cognitive performance during online activities. Objective: To investigate the oculomotor correlates of impaired performance of patients with mild Alzheimer's Clinical Syndrome (ACS) on a recently developed memory paradigm, namely the Short-Term Memory Binding Test (STMBT). Methods: We assessed a sample of eighteen healthy controls (HC) and eighteen patients with a diagnosis of mild ACS with the STMBT while we recorded their oculomotor behaviors using pupillometry and eye-tracking. Results: As expected, a group (healthy controls versus ACS) by condition (Unbound Colours versus Bound Colours) interaction was found whereby behavioral group differences were paramount in the Bound Colours condition. Healthy controls' pupils dilated significantly more in the Bound Colours than in the Unbound Colours condition, a discrepancy not observed in ACS patients. Furthermore, ROC analysis revealed the abnormal pupil behaviors distinguished ACS patients from healthy controls with values of sensitivity and specify of 100%, thus outperforming both recognition scores and gaze duration. Conclusion: The biological correlates of Short-Term Memory Binding impairments appear to involve a network much wider than we have thought to date, which expands across cortical and subcortical structures. We discuss these findings focusing on their implications for our understanding of neurocognitive phenotypes in the preclinical stages of Alzheimer's disease and potential development of cognitive biomarkers that can support ongoing initiatives to prevent dementia. |
Paige J. Foletta; Meaghan Clough; Allison M. McKendrick; Emma J. Solly; Owen B. White; Joanne Fielding Delayed onset of inhibition of return in visual snow syndrome Journal Article In: Frontiers in Neurology, vol. 12, pp. 738599, 2021. @article{Foletta2021, Visual snow syndrome (VSS) is a complex, sensory processing disorder. We have previously shown that visual processing changes manifest in significantly faster eye movements toward a suddenly appearing visual stimulus and difficulty inhibiting an eye movement toward a non-target visual stimulus. We propose that these changes reflect poor attentional control and occur whether attention is directed exogenously by a suddenly appearing event, or endogenously as a function of manipulating expectation surrounding an upcoming event. Irrespective of how attention is captured, competing facilitatory and inhibitory processes prioritise sensory information that is important to us, filtering out that which is irrelevant. A well-known feature of this conflict is the alteration to behaviour that accompanies variation in the temporal relationship between competing sensory events that manipulate facilitatory and inhibitory processes. A classic example of this is the “Inhibition of Return” (IOR) phenomenon that describes the relative slowing of a response to a validly cued location compared to invalidly cued location with longer cue/target intervals. This study explored temporal changes in the allocation of attention using an ocular motor version of Posner's IOR paradigm, manipulating attention exogenously by varying the temporal relationship between a non-predictive visual cue and target stimulus. Forty participants with VSS (20 with migraine) and 20 controls participated. Saccades were generated to both validly cued and invalidly cued targets with 67, 150, 300, and 500 ms cue/target intervals. VSS participants demonstrated delayed onset of IOR. Unlike controls, who exhibited IOR with 300 and 500 ms cue/target intervals, VSS participants only exhibited IOR with 500 ms cue/target intervals. These findings provide further evidence that attention is impacted in VSS, manifesting in a distinct saccadic behavioural profile, and delayed onset of IOR. Whether IOR is perceived as the build-up of an inhibitory bias against returning attention to an already inspected location or a consequence of a stronger attentional orienting response elicited by the cue, our results are consistent with the proposal that in VSS, a shift of attention elicits a stronger increase in saccade-related activity than healthy controls. This work provides a more refined saccadic behavioural profile of VSS that can be interrogated further using sophisticated neuroimaging techniques and may, in combination with other saccadic markers, be used to monitor the efficacy of any future treatments. |
Jolande Fooken; Pooja Patel; Christina B. Jones; Martin J. McKeown; Miriam Spering Preservation of eye movements in Parkinson's disease is stimulus and task specific Journal Article In: Journal of Neuroscience, vol. 42, no. 3, pp. 487–499, 2021. @article{Fooken2021, Parkinson's disease (PD) is a neurodegenerative disease that includes motor impairments, such as tremor, bradykinesia, and postural instability. Although eye movement deficits are commonly found in saccade and pursuit tasks, preservation of oculo- motor function has also been reported. Here we investigate specific task and stimulus conditions under which oculomotor function in PD is preserved. Sixteen PD patients and 18 healthy, age-matched controls completed a battery of movement tasks that included stationary or moving targets eliciting reactive or deliberate eye movements: pro-saccades, anti-saccades, visually guided pursuit, and rapid go/no-go manual interception. Compared with controls, patients demonstrated systematic impairments in tasks with stationary targets: pro-saccades were hypometric and anti-saccades were incorrectly initiated to- ward the cued target in ;35% of trials compared with 14% errors in controls. In patients, task errors were linked to short la- tency saccades, indicating abnormalities in inhibitory control. However, patients' eye movements in response to dynamic targets were relatively preserved. PD patients were able to track and predict a disappearing moving target and make quick go/no-go decisions as accurately as controls. Patients' interceptive hand movements were slower on average but initiated ear- lier, indicating adaptive processes to compensate for motor slowing. We conclude that PD patients demonstrate stimulus and task dependency of oculomotor impairments, and we propose that preservation of eye and hand movement function in PD is linked to a separate functional pathway through the superior colliculus-brainstem loop that bypasses the fronto-basal ganglia network. Our results demonstrate that studying oculomotor and hand movement function in PD can support disease diagno- sis and further our understanding of disease progression and dynamics. |
Léon Franzen; Zoey Stark; Aaron P. Johnson Individuals with dyslexia use a different visual sampling strategy to read text Journal Article In: Scientific Reports, vol. 11, pp. 6449, 2021. @article{Franzen2021, Individuals with dyslexia present with reading-related deficits including inaccurate and/or less fluent word recognition and poor decoding abilities. Slow reading speed and worse text comprehension can occur as secondary consequences of these deficits. Reports of visual symptoms such as atypical eye movements during reading gave rise to a search for these deficits' underlying mechanisms. This study sought to replicate established behavioral deficits in reading and cognitive processing speed while investigating their underlying mechanisms in more detail by developing a comprehensive profile of eye movements specific to reading in adult dyslexia. Using a validated standardized reading assessment, our findings confirm a reading speed deficit among adults with dyslexia. We observed different eye movements in readers with dyslexia across numerous eye movement metrics including the duration of a stop (i.e., fixation), the length of jumps (i.e., saccades), and the number of times a reader's eyes expressed a jump atypical for reading. We conclude that individuals with dyslexia visually sample written information in a laborious and more effortful manner that is fundamentally different from those without dyslexia. Our findings suggest a mix of aberrant cognitive linguistic and oculomotor processes being present in adults with dyslexia. |
Wendel M. Friedl; Andreas Keil Aversive conditioning of spatial position sharpens neural population-level tuning in visual cortex and selectively alters alpha-band activity Journal Article In: Journal of Neuroscience, vol. 41, no. 26, pp. 5723–5733, 2021. @article{Friedl2021, Processing capabilities for many low-level visual features are experientially malleable, aiding sighted organisms in adapting to dynamic environments. Explicit instructions to attend a specific visual field location influence retinotopic visuocortical activity, amplifying responses to stimuli appearing at cued spatial positions. It remains undetermined both how such prioritization affects surrounding nonprioritized locations, and if a given retinotopic spatial position can attain enhanced cortical representation through experience rather than instruction. The current report examined visuocortical response changes as human observers (N = 51, 19 male) learned, through differential classical conditioning, to associate specific screen locations with aversive outcomes. Using dense-array EEG and pupillometry, we tested the preregistered hypotheses of either sharpening or generalization around an aversively associated location following a single conditioning session. Competing hypotheses tested whether mean response changes would take the form of a Gaussian (generalization) or difference-of-Gaussian (sharpening) distribution over spatial positions, peaking at the viewing location paired with a noxious noise. Occipital 15 Hz steady-state visual evoked potential responses were selectively heightened when viewing aversively paired locations and displayed a nonlinear, difference-of-Gaussian profile across neighboring locations, consistent with suppressive surround modulation of nonprioritized positions. Measures of alpha-band (8-12 Hz) activity were differentially altered in anterior versus posterior locations, while pupil diameter exhibited selectively heightened responses to noise-paired locations but did not evince differences across the nonpaired locations. These results indicate that visuocortical spatial representations are sharpened in response to location-specific aversive conditioning, while top-down influences indexed by alpha-power reduction exhibit posterior generalization and anterior sharpening. |
R. Frömer; H. Lin; C. K. Dean Wolf; M. Inzlicht; A. Shenhav Expectations of reward and efficacy guide cognitive control allocation Journal Article In: Nature Communications, vol. 12, pp. 1030, 2021. @article{Froemer2021, The amount of mental effort we invest in a task is influenced by the reward we can expect if we perform that task well. However, some of the rewards that have the greatest potential for driving these efforts are partly determined by factors beyond one's control. In such cases, effort has more limited efficacy for obtaining rewards. According to the Expected Value of Control theory, people integrate information about the expected reward and efficacy of task performance to determine the expected value of control, and then adjust their control allocation (i.e., mental effort) accordingly. Here we test this theory's key behavioral and neural predictions. We show that participants invest more cognitive control when this control is more rewarding and more efficacious, and that these incentive components separately modulate EEG signatures of incentive evaluation and proactive control allocation. Our findings support the prediction that people combine expectations of reward and efficacy to determine how much effort to invest. |
Birte Gestefeld; Jan Bernard Marsman; Frans W. Cornelissen How free-viewing eye movements can be used to detect the presence of visual field defects in glaucoma patients Journal Article In: Frontiers in Medicine, vol. 8, pp. 689910, 2021. @article{Gestefeld2021, Purpose: There is a need for more intuitive perimetric screening methods, which can also be performed by elderly people and children currently unable to perform standard automated perimetry (SAP). Ideally, these methods should also be easier to administer, such that they may be used outside of a regular clinical environment. We evaluated the suitability of various methodological and analytical approaches for detecting and localizing VFD in glaucoma patients, based on eye movement recordings. Methods: The present study consisted of two experiments. In experiment 1, we collected data from 20 glaucoma patients and 20 age-matched controls, who monocularly viewed 28 1-min video clips while their eyes were being tracked. In experiment 2, we re-analyzed a published dataset, that contained data of 44 glaucoma patients and 32 age-matched controls who had binocularly viewed three longer-duration (3, 5, and 7 min) video clips. For both experiments, we first examined if the two groups differed in the basic properties of their fixations and saccades. In addition, we computed the viewing priority (VP) of each participant. Following a previously reported approach, for each participant, we mapped their fixation locations and used kernel Principal Component Analysis (kPCA) to distinguish patients from controls. Finally, we attempted to reconstruct the location of a patient's VFD by mapping the relative fixation frequency and the VP across their visual field. Results: We found direction dependent saccade amplitudes in glaucoma patients that often differed from those of the controls. Moreover, the kPCA indicated that the fixation maps of the two groups separated into two clusters based on the first two principal components. On average, glaucoma patients had a significantly lower VP than the controls, with this decrease depending on the specific video viewed. Conclusions: It is possible to detect the presence of VFD in glaucoma patients based on their gaze behavior made during video viewing. While this corroborates earlier conclusions, we show that it requires participants to view the videos monocularly. Nevertheless, we could not reconstruct the VFD with any of the evaluated methods, possibly due to compensatory eye movements made by the glaucoma patients. |
Anna C. Geuzebroek; Karlijn Woutersen; Albert V. Berg When you do not get the whole picture: Scene perception after occipital cortex lesions Journal Article In: Frontiers in Neuroscience, vol. 15, pp. 716273, 2021. @article{Geuzebroek2021, Background: Occipital cortex lesions (OCLs) typically result in visual field defects (VFDs) contralateral to the damage. VFDs are usually mapped with perimetry involving the detection of point targets. This, however, ignores the important role of integration of visual information across locations in many tasks of everyday life. Here, we ask whether standard perimetry can fully characterize the consequences of OCLs. We compare performance on a rapid scene discrimination task of OCL participants and healthy observers with simulated VFDs. While the healthy observers will only suffer the loss of part of the visual scene, the damage in the OCL participants may further compromise global visual processing. Methods: VFDs were mapped with Humphrey perimetry, and participants performed two rapid scene discrimination tasks. In healthy participants, the VFDs were simulated with hemi- and quadrant occlusions. Additionally, the GIST model, a computational model of scene recognition, was used to make individual predictions based on the VFDs. Results: The GIST model was able to predict the performance of controls regarding the effects of the local occlusion. Using the individual predictions of the GIST model, we can determine that the variability between the OCL participants is much larger than the extent of the VFD could account for. The OCL participants can further be categorized as performing worse, the same, or better as their VFD would predict. Conclusions: While in healthy observers the extent of the simulated occlusion accounts for their performance loss, the OCL participants' performance is not fully determined by the extent or shape of their VFD as measured with Humphrey perimetry. While some OCL participants are indeed only limited by the local occlusion of the scene, for others, the lesions compromised the visual network in a more global and disruptive way. Yet one outperformed a healthy observer, suggesting a possible adaptation to the VFD. Preliminary analysis of neuroimaging data suggests that damage to the lateral geniculate nucleus and corpus callosum might be associated with the larger disruption of rapid scene discrimination. We believe our approach offers a useful behavioral tool for investigating why similar VFDs can produce widely differing limitations in everyday life. |
Supriya Ghosh; John H. R. Maunsell Single trial neuronal activity dynamics of attentional intensity in monkey visual area V4 Journal Article In: Nature Communications, vol. 12, pp. 2003, 2021. @article{Ghosh2021, Understanding how activity of visual neurons represents distinct components of attention and their dynamics that account for improved visual performance remains elusive because single-unit experiments have not isolated the intensive aspect of attention from attentional selectivity. We isolated attentional intensity and its single trial dynamics as determined by spatially non-selective attentional performance in an orientation discrimination task while recording from neurons in monkey visual area V4. We found that attentional intensity is a distinct cognitive signal that can be distinguished from spatial selectivity, reward expectations and motor actions. V4 spiking on single trials encodes a combination of sensory and cognitive signals on different time scales. Attentional intensity and the detection of behaviorally relevant sensory signals are well represented, but immediate reward expectation and behavioral choices are poorly represented in V4 spiking. These results provide a detailed representation of perceptual and cognitive signals in V4 that are crucial for attentional performance. |
Steven M. Gillespie; Ian J. Mitchell; Anthony R. Beech; Pia Rotshtein Processing of emotional faces in sexual offenders with and without child victims: An eye-tracking study with pupillometry Journal Article In: Biological Psychology, vol. 163, pp. 108141, 2021. @article{Gillespie2021, Socio-affective dysfunction is a risk-factor for sexual offense recidivism. However, it remains unknown whether men who have sexually offended with and without child victims show differences in eye scan paths and autonomic responsivity while viewing facial expressions of emotion. We examined differences in accuracy of emotion recognition, eye movements, and pupil dilation responses between sex offenders with child victims, sex offenders without child victims, and a group of non-offenders living in the community. Sex offenders without child victims looked for longer at the eyes than sex offenders with child victims and non-offenders. Men without child victims also scored higher for psychopathy linked disinhibition, and these traits were associated with looking longer at the eyes of afraid faces. We found no evidence for group differences in accuracy, visual attention to the mouth, or pupil dilation responses. Our findings have implications for understanding the nature of socio-affective dysfunction in sexual offenders. |
Doria M. Gold; John-Ross Rizzo; Yuen Shan Christine Lee; Amanda Childs; Todd E. Hudson; John Martone; Yuka K. Matsuzawa; Felicia Fraser; Joseph H. Ricker; Weiwei Dai; Ivan Selesnick; Laura J. Balcer; Steven L. Galetta; Janet C. Rucker King-Devick test performance and cognitive dysfunction after concussion: A pilot eye movement study Journal Article In: Brain Sciences, vol. 11, pp. 1571, 2021. @article{Gold2021, (1) Background: The King-Devick (KD) rapid number naming test is sensitive for concussion diagnosis, with increased test time from baseline as the outcome measure. Eye tracking during KD performance in concussed individuals shows an association between inter-saccadic interval (ISI) (the time between saccades) prolongation and prolonged testing time. This pilot study retrospectively assesses the relation between ISI prolongation during KD testing and cognitive performance in persistently-symptomatic individuals post-concussion. (2) Results: Fourteen participants (median age 34 years; 6 women) with prior neuropsychological assessment and KD testing with eye tracking were included. KD test times (72.6 ± 20.7 s) and median ISI (379.1 ± 199.1 msec) were prolonged compared to published normative values. Greater ISI prolongation was associated with lower scores for processing speed (WAIS-IV Coding |
Edward J. Golob; Jeremy T. Nelson; Jaelle Scheuerman; Kristen B. Venable; Jeffrey R. Mock Auditory spatial attention gradients and cognitive control as a function of vigilance Journal Article In: Psychophysiology, vol. 58, no. 10, pp. e13903, 2021. @article{Golob2021, Selection and effort are central to attention, yet it is unclear whether they draw on a common pool of cognitive resources, and if so, whether there are differences for early versus later stages of cognitive processing. This study assessed effort by quantifying the vigilance decrement, and spatial processing at early and later stages as a function of time-on-task. Participants performed an auditory spatial attention task, with occasional “catch” trials requiring no response. Psychophysiological measures included bilateral cerebral blood flow (transcranial Doppler), pupil dilation, and blink rate. The shape of attention gradients using reaction time indexed early processing, and did not significantly vary over time. Later stimulus-response conflict was comparable over time, except for a reduction to left hemispace stimuli. Target and catch trial accuracy decreased with time, with a more abrupt decrease for catch versus target trials. Diffusion decision modeling found progressive decreases in information accumulation rate and non-decision time, and the adoption of more liberal response criteria. Cerebral blood flow increased from baseline and then decreased over time, particularly in the left hemisphere. Blink rate steadily increased over time, while pupil dilation increased only at the beginning and then returned towards baseline. The findings suggest dissociations between resources for selectivity and effort. Measures of high subjective effort and temporal declines in catch trial accuracy and cerebral blood flow velocity suggest a standard vigilance decrement was evident in parallel with preserved selection. Different attentional systems and classes of computations that may account for dissociations between selectivity versus effort are discussed. |
Jackson E. Graves; Paul Egré; Daniel Pressnitzer; Vincent Gardelle An implicit representation of stimulus ambiguity in pupil size Journal Article In: Proceedings of the National Academy of Sciences, vol. 118, no. 48, pp. e2107997118, 2021. @article{Graves2021, To guide behavior, perceptual systems must operate on intrinsically ambiguous sensory input. Observers are usually able to acknowledge the uncertainty of their perception, but in some cases, they critically fail to do so. Here, we show that a physiological correlate of ambiguity can be found in pupil dilation even when the observer is not aware of such ambiguity. We used a well-known auditory ambiguous stimulus, known as the tritone paradox, which can induce the perception of an upward or downward pitch shift within the same individual. In two experiments, behavioral responses showed that listeners could not explicitly access the ambiguity in this stimulus, even though their responses varied from trial to trial. However, pupil dilation was larger for the more ambiguous cases. The ambiguity of the stimulus for each listener was indexed by the entropy of behavioral responses, and this entropy was also a significant predictor of pupil size. In particular, entropy explained additional variation in pupil size independent of the explicit judgment of confidence in the specific situation that we investigated, in which the two measures were decoupled. Our data thus suggest that stimulus ambiguity is implicitly represented in the brain even without explicit awareness of this ambiguity. |
Michael A. Johns; Paola E. Dussias Of revistas and magacínes: Lexical competition in the online processing of established loanwords Journal Article In: Journal of Second Language Studies, vol. 4, no. 2, pp. 375–411, 2021. @article{Johns2021, The transfer of words from one language to another is ubiquitous in many of the world's languages. While loanwords have a rich literature in the fields of historical linguistics, language contact, and sociolinguistics, little work has been done examining how loanwords are processed by bilinguals with knowledge of both the source and recipient languages. The present study uses pupillometry to compare the online processing of established loanwords in Puerto Rican Spanish to native Spanish words by highly proficient Puerto Rican Spanish-English bilinguals. Established loanwords elicited a significantly larger pupillary response than native Spanish words, with the pupillary response modulated by both the frequency of the loanword itself and of the native Spanish counterpart. These findings suggest that established loanwords are processed differently than native Spanish words and compete with their native equivalents, potentially due to both intra- and inter-lingual effects of saliency. |
Tamás Káldi; Anna Babarczy Linguistic focus guides attention during the encoding and refreshing of working memory content Journal Article In: Journal of Memory and Language, vol. 116, pp. 104187, 2021. @article{Kaldi2021, Focus is a linguistic device that marks a piece of information within an utterance as most relevant, as when emphasis is placed by the speaker on a word using phonological stress, special intonation, or prosodic prominence. The question addressed in the present study is whether the use of linguistic focus is best seen as a means of directing the listener's attention. We investigated attention allocation on the part of the listener to linguistically focused elements in working memory in a series of eye-tracking experiments. We concentrated on two processes: the encoding of the focused element and its retention. Attentional load during encoding was measured by pupil dilation, and attention allocation during retention was estimated from fixations to locations of previously present visual stimuli on a blank screen. It was found that i) more attention was allocated during the processing of sentences with linguistic focus and ii) linguistically focused elements received more attention during memory retention. However, when the task demanded the sharing of attention, the advantage of the focused element during retention disappeared. Further experiments showed that when verbal stimuli whose prominence was not linguistically marked were presented, the patterns of attention allocation associated with linguistic focus during retention replicated. These results lend further support to the claim that linguistic focus is a grammaticalized means of expressing prominence, and as such, functions as an attention capturing device. |
Kei Kanari; Hirohiko Kaneko Pupil response is modulated with optokinetic nystagmus in transparent motion Journal Article In: Journal of the Optical Society of America A, vol. 38, no. 2, pp. 149–156, 2021. @article{Kanari2021, When two visual patterns moving in opposite directions are superimposed on the same depth plane, they appear to have two transparent surfaces moving independently (transparent motion). Additionally, the direction of the slowphase ofoptokinetic nystagmus (OKN) corresponds to the direction ofmotion that dominates the perceptual appearance. This study examines whether pupil changes correspond to the luminance of the dominated objects related to the transition of the slow-phase direction in OKN following objects. Stimuli consisted oftwo random dot patterns ofdifferent luminance that moved in opposite directions. The results showed that pupil size changed in accordance with the luminance ofthe pattern in the slowphase ofOKNimmediately after OKN transition. This suggests that pupil size is modulated withOKNin transparent motion. |
Elif Canseza Kaplan; Anita E. Wagner; Paolo Toffanin; Deniz Başkent Do musicians and non-musicians differ in speech-on-speech processing? Journal Article In: Frontiers in Psychology, vol. 12, pp. 623787, 2021. @article{Kaplan2021, Earlier studies have shown that musically trained individuals may have a benefit in adverse listening situations when compared to non-musicians, especially in speech-on-speech perception. However, the literature provides mostly conflicting results. In the current study, by employing different measures of spoken language processing, we aimed to test whether we could capture potential differences between musicians and non-musicians in speech-on-speech processing. We used an offline measure of speech perception (sentence recall task), which reveals a post-task response, and online measures of real time spoken language processing: gaze-tracking and pupillometry. We used stimuli of comparable complexity across both paradigms and tested the same groups of participants. In the sentence recall task, musicians recalled more words correctly than non-musicians. In the eye-tracking experiment, both groups showed reduced fixations to the target and competitor words' images as the level of speech maskers increased. The time course of gaze fixations to the competitor did not differ between groups in the speech-in-quiet condition, while the time course dynamics did differ between groups as the two-talker masker was added to the target signal. As the level of two-talker masker increased, musicians showed reduced lexical competition as indicated by the gaze fixations to the competitor. The pupil dilation data showed differences mainly in one target-to-masker ratio. This does not allow to draw conclusions regarding potential differences in the use of cognitive resources between groups. Overall, the eye-tracking measure enabled us to observe that musicians may be using a different strategy than non-musicians to attain spoken word recognition as the noise level increased. However, further investigation with more fine-grained alignment between the processes captured by online and offline measures is necessary to establish whether musicians differ due to better cognitive control or sound processing. |
Brigitte C. Kaufmann; Dario Cazzoli; Monica Koenig-Bruhin; René M. Müri; Tobias Nef; Thomas Nyffeler In: Frontiers in Neuroscience, vol. 15, pp. 640049, 2021. @article{Kaufmann2021, Spatial neglect has been shown to occur in 17–65% of patients after acute left-hemispheric stroke. One reason for this varying incidence values might be that left-hemispheric stroke is often accompanied by aphasia, which raises difficulties in assessing attention deficits with conventional neuropsychological tests entailing verbal instructions. Video-oculography during free visual exploration (FVE) requires only little understanding of simple non-verbal instruction and has been shown to be a sensitive and reliable tool to detect spatial neglect in patients with right-hemispheric stroke. In the present study, we aimed to investigate the feasibility of FVE to detect neglect in 10 left-hemispheric stroke patients with mild to severe aphasia as assessed by means of the Token Test, Boston Naming Test and Aachener Aphasie Test. The patient's individual deviation between eye movement calibration and validation was recorded and compared to 20 age-matched healthy controls. Furthermore, typical FVE parameters such as the landing point of the first fixation, the mean gaze position (in ° of visual angle), the number and duration of visual fixations and the mean visual exploration area were compared between groups. In addition, to evaluate for neglect, the Bells cancellation test was performed and neglect severity in daily living was measured by means of the Catherine Bergego Scale (CBS). Our results showed that the deviation between calibration and validation did not differ between aphasia patients and healthy controls highlighting its feasibility. Furthermore, FVE revealed the typical neglect pattern with a significant leftward shift in visual exploration bahaviour, which highly correlated with neglect severity as assessed with CBS. The present study provides evidence that FVE has the potential to be used as a neglect screening tool in left-hemispheric stroke patients with aphasia in which compliance with verbal test instructions may be compromised by language deficits. |
Brandon Keehn; Girija Kadlaskar; Sophia Bergmann; Rebecca McNally Keehn; Alexander Francis Attentional disengagement and the locus coeruleus – norepinephrine system in children With autism spectrum disorder Journal Article In: Frontiers in Integrative Neuroscience, vol. 15, pp. 716447, 2021. @article{Keehn2021, Background: Differences in non-social attentional functions have been identified as among the earliest features that distinguish infants later diagnosed with autism spectrum disorder (ASD), and may contribute to the emergence of core ASD symptoms. Specifically, slowed attentional disengagement and difficulty reorienting attention have been found across the lifespan in those at risk for, or diagnosed with, ASD. Additionally, the locus coeruleus-norepinephrine (LC-NE) system, which plays a critical role in arousal regulation and selective attention, has been shown to function atypically in ASD. While activity of the LC-NE system is associated with attentional disengagement and reorienting in typically developing (TD) individuals, it has not been determined whether atypical LC-NE activity relates to attentional disengagement impairments observed in ASD. Objective: To examine the relationship between resting pupil diameter (an indirect measure of tonic LC-NE activation) and attentional disengagement in children with ASD. Methods: Participants were 21 school-aged children with ASD and 20 age- and IQ-matched TD children. The study consisted of three separate experiments: a resting eye-tracking task and visual and auditory gap-overlap paradigms. For the resting eye-tracking task, pupil diameter was monitored while participants fixated a central crosshair. In the gap-overlap paradigms, participants were instructed to fixate on a central stimulus and then move their eyes to peripherally presented visual or auditory targets. Saccadic reaction times (SRT), percentage of no-shift trials, and disengagement efficiency were measured. Results: Children with ASD had significantly larger resting pupil size compared to their TD peers. The groups did not differ for overall SRT, nor were there differences in SRT for overlap and gap conditions between groups. However, the ASD group did evidence impairments in disengagement (larger step/gap effects, higher percentage of no-shift trials, and reduced disengagement efficiency) compared to their TD peers. Correlational analyses showed that slower, less efficient disengagement was associated with increased pupil diameter. Conclusion: Consistent with prior reports, children with ASD show significantly larger resting pupil diameter, indicative of atypically elevated tonic LC-NE activity. Associations between pupil size and measures of attentional disengagement suggest that atypically increased tonic activation of the LC-NE system may be associated with poorer attentional disengagement in children with ASD. |