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Kadosh, O.

Publications and source records attributed to Kadosh, O..

4 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.

neuroscience↗

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↗

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.

neuroscience↗

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.

neuroscience↗