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Bonneh, Y. S.

Publications and source records attributed to Bonneh, Y. S..

7 recordsLinked to original sources

Minimally verbal children with autism may see the global, but point local: A behavioral and eye-tracking study in visual perceptual processing

Recent work suggests that pointing based assessments may underestimate or mischaracterize perceptual and cognitive abilities in minimally verbal autism (mvASD). Extending this line of work, we address the classic global local question by testing whether mvASD children access global visual structure and whether it is consistently expressed in behavior using Kanizsa illusory contours (KIC) and circular colinear contours (CC). Typically developing (TD) and mvASD children viewed KIC and CC stimuli on a touchscreen while spontaneous eye gaze and pointing were recorded. Participants also completed a goal directed drag and drop matching task that required selecting the solid shape corresponding to the global KIC configuration. In spontaneous responses, mvASD children were more drawn to local elements (e.g., individual inducers, the CC frame, single Gabors) and showed less centralized responding than TD peers. Notably, CC pointing was often anchored to one half of the contour regardless of contour screen location, suggesting object centered global selection. Also, in the drag and drop task, approx. 90% of mvASD participants performed above chance in at least one condition and half performed at ceiling, demonstrating accurate global matching. These findings suggest that global structure is available in mvASD but may be underweighted in spontaneous response selection under ambiguity, consistent with the Affordance Competition Hypothesis and ambiguity resolution accounts. Lay SummaryAutism research often asks whether autistic people can see the wood for the trees--integrate parts into a coherent whole. This is difficult to test in minimally verbal autism because many standard tasks rely on a single pointing response that may not reflect what a child actually perceives. In our study, children viewed visual illusions in which a clear shape seems to appear even though it is not actually drawn, for example, a triangle you see because several Pac Man shapes are arranged in just the right way, while we measured both where they looked and where they touched the screen. Minimally verbal autistic children were often more drawn to the smaller parts than typically developing peers, yet when a simple drag and drop game required an explicit choice of the overall shape, most selected the correct global shape. Together, the findings suggest that global structure can be available in mvASD, but its expression in spontaneous behavior may be more context dependent under uncertainty, highlighting the value of using more than one way to measure ability.

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Hidden Literacy in Minimally Verbal Autistic Individuals Revealed by Eye Gaze

Minimally verbal autistic individuals (mvASD) are often presumed to have severe cognitive and language impairments based on their poor performance on standardized assessments requiring voluntary motor responses, such as pointing. However, emerging evidence suggests that these individuals may possess latent cognitive abilities. Here, we introduce the Cued Looking Paradigm (CLP), a novel eye-tracking method that bypasses motor requirements by capturing automatic gaze responses to language-based stimuli. In our study, 35 minimally verbal autistic adolescents and adults were presented with spoken or written words, followed by a pair of images (target and foil) as their eye movements were recorded. Among mvASD participants with usable eye-tracking data (n = 30), the majority (80%) demonstrated hidden receptive language and reading abilities, as evidenced by eye-gaze measures, including temporal dynamics and spatial displacement, that were comparable to those observed in neurotypical controls. In contrast, the same mvASD individuals averaged only 57% accuracy when asked to read and point to the target picture, revealing a significant gap between reporting via pointing and actual lexical-semantic knowledge. Furthermore, pupil dilation analysis during tasks indicated reduced arousal recruitment in mvASD participants, potentially implicating dysregulation of the locus coeruleus-norepinephrine (LC-NE) system associated with the performance gap between pointing and eye-gaze. These findings challenge assumptions of global intellectual limitation while confirming specific lexical-semantic competence among mvASD individuals. Results highlight the need for, and provide, alternative- assessments that bypass manual motor responses. The CLP shows promise for revealing cognitive and language abilities, with important implications for both research and education. Significance StatementStandard language tests implicitly assume that a person can point or speak. Although minimally verbal individuals can point, this response may not reliably reflect comprehension. Using a simple eye-tracking task that replaces pointing with automatic gaze shifts, we show that most mvASD participants accurately match spoken or written words to pictures--even though they fail the same task when pointing is required. This finding challenges the assumption that absence of speech is typically associated with absence of understanding and reveals bias in common assessments. Tools that bypass manual motor demands by using eye movements, such as the Cued Looking Paradigm, together with changes in assessment and intervention, could transform diagnosis, guide education, and open new research avenues on covert language processing.

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Pattern-Induced Visual Discomfort and Its Temporal Summation Revealed by Pupillary Measures

Viewing repetitive striped patterns can induce pattern glare, experienced as visual discomfort (VD). While previous studies examined either pupillary responses or VD separately, few have investigated how they covary or evolve with repeated exposure. This study tested whether pupillary dynamics could serve as an objective "aversometer" -- a physiological marker of individual visual sensitivity beyond subjective reports. Across four experiments (preliminary: n = 97; main: n = 70 for spatial frequency, n = 46 for central field size, n = 36 for central blank, with partial overlap), we manipulated spatial frequency, central field size, and surround field size of square-wave gratings (0.5-3 s) while measuring both discomfort and pupil size. Higher spatial frequencies and larger pattern areas elicited stronger pupillary constriction and greater discomfort, whereas repeated exposures produced cumulative increases in discomfort and decreases in baseline pupil size, consistent with visual strain rather than adaptation. To assess the potential of pupillometry as an aversometer, we examined individual differences in the main spatial-frequency experiment (controlled viewing distance, n = 42). A paradoxical pattern emerged: within participants, stronger stimuli produced greater constriction, but individuals with higher overall discomfort showed weaker constriction and stronger late redilation. Similar dissociations between subjective sensitivity and pupillary responses have been noted in studies of light-induced discomfort, suggesting that related mechanisms may contribute, although their specific physiological basis remains unclear. Overall, our findings clarify how pattern-induced discomfort evolves over time and across individuals and highlight pupillometrys potential as a sensitive, objective tool for assessing visual sensitivity. HighlightsO_LIStriped patterns systematically increased discomfort and pupillary constriction C_LIO_LIRepeated exposure led to progressive discomfort and shrinking baseline pupil C_LIO_LIAmong high-sensitivity participants, weaker constriction and stronger redilation appeared C_LIO_LIThe paradox may reflect interindividual autonomic differences under visual stress C_LIO_LIPupillometry shows promise as an objective marker of visual sensitivity C_LI

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Children with Autism Show Impaired Oculomotor Entrainment to Predictable Stimuli

Individuals with Autism Spectrum Disorder (ASD) show altered synchronization with external events, which may underlie the rigidity and reduced adaptability that characterize the condition. We previously demonstrated that electroencephalography (EEG) recorded from children with ASD reveals impaired neuronal entrainment to predictable visual sequences. Whether similar effects are reflected in other physiological signals remains unclear. Here, we investigated whether eye movement and pupil dilation responses exhibit comparable entrainment differences in ASD. Microsaccades (MS) and pupil diameter were recorded from 31 children with ASD (6-9 years) and 21 age- and IQ-matched typically developing (TD) controls during a task in which four equally spaced visual cues preceded an auditory target. We analyzed modulation of MS release time (MS RT) and pupil response time (pupil RT), along with trial-by-trial variability, as indices of ocular entrainment. Both groups exhibited periodic oculomotor responses to the cues, including phasic MS inhibition and repeated pupil constrictions. In TD children, MS RT and pupil RT increased across cues while their variability decreased, consistent with progressive temporal alignment. These effects were significantly reduced in the ASD group. Oculomotor entrainment measures correlated with EEG inter-trial phase coherence (ITPC) in TD but not ASD children. They also correlated with behavioral response times in both groups, and moderately correlated with autism severity scores. Children with ASD thus showed diminished oculomotor modulation and greater variability in response to predictable stimuli, paralleling earlier EEG findings. These results suggest convergence across physiological systems in indexing impaired processing of predictability in ASD and highlight the promise of multimodal approaches.

neuroscience↗

Minimally verbal children with autism may see the point, but do not (always) point to what they see:A behavioral and eye-tracking study in visual perceptual processing

During typical development, non-social visual object recognition emerges in the first year of life, engaging low-level visual cues and higher-level mechanisms involving inference and prior knowledge. How these processes function in minimally verbal autism (mvASD) remains poorly understood. We studied children with mvASD (n=22, 6-11 years) using touchscreen-based oddball and contour-detection tasks targeting low-level stimuli (e.g. shape and orientation), and mid-level stimuli (e.g. illusory Kanizsa contours and 3D shapes). Pointing and eye-gaze responses were measured. Typically developing children (n=22, 6-12 years) served as a reference group. Accuracy and reaction-time profiles among mvASD participants were heterogeneous across experimental visual tasks and standardized developmental measures. All mvASD participants detected targets in the easiest condition, and approximately half succeeded across low-level tasks. Overall performance declined with increasing visual complexity, consistent with attenuated inference-based processing; communication ability and nonverbal reasoning together accounted for approximately 69% of between-participant variance in visual task performance. Critically, exploratory analyses suggested systematic perception-action dissociations rather than random error. First, the majority of participants who failed to point correctly (n=9) reliably fixated the correct target. Second, in the Kanizsa oddball task, nearly half of successful mvASD participants pointed to local inducers rather than the illusory figure center, unlike TDs. Third, more participants showed within-age-range nonverbal reasoning performance on Ravens colorful progressive matrices when responding by puzzle placement than by pointing. These converging findings challenge interpretations of mvASD performance as reflecting perceptual or cognitive capacity alone, suggesting visual signals may guide action selection differently in mvASD. Lay SummaryMinimally verbal children with autism showed individual differences in visual processing tasks. While developmental measures like communication ability and reasoning skills predicted most of the variation in performance, exploratory observations revealed an intriguing pattern: the same children sometimes succeeded when using their eyes to indicate answers but failed when pointing or performing better when placing puzzle pieces than pointing in a booklet to identical visual display. Several children who correctly detected illusory triangular shapes consistently touched the corner pieces rather than the triangle centers. These patterns suggest that performance depends not only on developmental and visual perceptual abilities, but also on how children are asked to respond. Parents and educators should consider: might a child who fails a pointing-based test succeed with a different response method?

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Bedside Assessment of Visual Tracking in Traumatic Brain Injury: Comparing Simple and Predictive Paradigms Using Multiple Oculomotor Markers

Oculomotor function is a sensitive marker of neurological impairment with smooth pursuit deficiencies investigated in various disorders. However, the oculomotor deficits following traumatic brain injury (TBI) have not been fully characterized. In this study, we employed a novel bedside eye-tracking paradigm to assess oculomotor dysfunction in 30 TBI patients and 30 age-matched controls. Our paradigm utilized short, repeated linear tracking segments with head-free recording, enabling the extraction of multiple oculomotor indices, including saccadic pursuit, tracking deviation under occlusion, initial tracking speed, initial saccade latency, pupil response, and vergence instability. TBI patients exhibited widespread deficits across these indices (AUC = 0.71-0.84), which correlated significantly with functional recovery, as measured by the Functional Independence Measure (R = 0.41-0.78, p < 0.001) but not with the initial Glasgow Coma Scale scores. These findings suggest that TBI disrupts multiple components of the oculomotor system, extending to predictive tracking, pupil-linked arousal, and binocular coordination. Additionally, preliminary testing in disorders of consciousness (DOC) patients revealed fragmented tracking, suggesting a potential application for assessing perceptual awareness. Our findings support the use of eye tracking as a promising tool for quantifying brain function in TBI, with potential applications in prognosis, rehabilitation monitoring, and broader neurological assessment.

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Face Familiarity Revealed by Fixational Eye Movements and Fixation-Related Potentials in Free Viewing

Event-related potentials (ERPs) and the oculomotor inhibition (OMI) in response to transient visual stimuli are known to be sensitive to different stimulus properties, including attention and expectation. In natural vision, transient stimulation of the visual cortex is generated primarily by saccades. Recent studies suggest that the core EEG components in free viewing, induced by saccades (fixation-related potentials, RPs), are similar to the ERP components with flashed stimuli. We have recently found that the OMI in response to flashed stimuli is sensitive to face familiarity. Here, we investigated whether fixation-related-potentials (FRPs) and microsaccade inhibition (OMI) in free viewing are sensitive to face familiarity. Observers (N=15) freely watched a slideshow of seven unfamiliar and one familiar world leaders facial images presented randomly for 4-seconds periods, with multiple images per identity. We measured the occipital fixation-related N1 relative to the P1 magnitude as well as the associated fixation-triggered OMI. We found that the average N1 was significantly smaller and the OMI was shorter for the familiar face, compared with any of the 7 unfamiliar faces. Moreover, the P1 was suppressed across saccades for the familiar but not for the unfamiliar faces. Overall, the results indicate that the occipital FRP and the OMI in free viewing are sensitive to face familiarity; this could perhaps be used as a novel physiological measure for studying hidden suppressed memories.

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