Abstract
Individuals on the autism spectrum often exhibit atypicality in their sensory perception, but the neural underpinnings of these perceptual differences remain incompletely understood. One proposed mechanism is an imbalance in higher-order feedback re-entrant inputs to early sensory cortices during sensory perception, leading to increased propensity to focus on local object features over global context. We explored this theory by measuring visual evoked potentials during contour integration as considerable work has revealed that these processes are largely driven by feedback inputs from higher-order ventral visual stream regions. We tested the hypothesis that autistic individuals would have attenuated evoked responses to illusory contours compared to neurotypical controls. Electrophysiology was acquired while 29 autistic and 31 neurotypical children (7-17 years-old, inclusive of both males and females) passively viewed a random series of Kanizsa figure stimuli, each consisting of four inducers that were aligned either at random rotational angles or such that contour integration would form an illusory square. Autistic children demonstrated attenuated automatic contour integration over lateral occipital regions relative to neurotypical controls. The data are discussed in terms of the role of predictive feedback processes on perception of global stimulus features and the notion that weakened “priors” may play a role in the visual processing anomalies seen in autism.
SIGNIFICANCE STATEMENT:
Children on the autism spectrum differ from typically developing children in many aspects of their processing of sensory stimuli. One proposed mechanism for these differences is an imbalance in higher order feedback to primary sensory regions, leading to an increased focus on local object features rather than global context. However, systematic investigation of these feedback mechanisms remains limited. Using electroencephalography (EEG) and a visual illusion paradigm that is highly dependent on intact feedback processing, we demonstrated significantly disruptions to visual feedback processing in children with autism. This provides much needed experimental evidence that advances our understanding of the contribution of feedback processing to visual perception in autism spectrum disorder.
Footnotes
All authors affirm that they have no financial interests or other potential conflicts of interest to report.
This work was supported by the Ernest J. Del Monte Institute for Neuroscience Pilot Program with funding from the Kilian J. and Caroline F. Schmitt Foundation (to EGF and JJF). Participant recruitment and phenotyping were conducted through the UR-IDDRC Human Clinical Phenotyping and Recruitment Core, and electrophysiological recordings and eye-tracking were supported by the UR-IDDRC Translational Neuroimaging and Neurophysiology Core, which are supported by a center grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (P50 HD103536 – to JJF). Participant recruitment and phenotyping at Einstein College of Medicine was supported in part by the Human Clinical Phenotyping Core of the Rose F. Kennedy IDDRC, supported by a center grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (P50 HD105352– to SM). Dr. Knight was supported by the University of Rochester Medical Center Department of Pediatrics Chair Fellow Award and through Kyle Family Fellowship support. Dr. Evans was supported by a post-doctoral training fellowship through the Center for Visual Sciences at the University of Rochester (NIH T32 EY007125).
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
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