title: Luminance- and texture-defined information processing in school-aged children with autism.
abstract: According to the complexity-specific hypothesis, the efficacy with which individuals with autism spectrum disorder (ASD) process visual information varies according to the extensiveness of the neural network required to process stimuli. Specifically, adults with ASD are less sensitive to texture-defined (or second-order) information, which necessitates the implication of several cortical visual areas. Conversely, the sensitivity to simple, luminance-defined (or first-order) information, which mainly relies on primary visual cortex (V1) activity, has been found to be either superior (static material) or intact (dynamic material) in ASD. It is currently unknown if these autistic perceptual alterations are present in childhood. In the present study, behavioural (threshold) and electrophysiological measures were obtained for static luminance- and texture-defined gratings presented to school-aged children with ASD and compared to those of typically developing children. Our behavioural and electrophysiological (P140) results indicate that luminance processing is likely unremarkable in autistic children. With respect to texture processing, there was no significant threshold difference between groups. However, unlike typical children, autistic children did not show reliable enhancements of brain activity (N230 and P340) in response to texture-defined gratings relative to luminance-defined gratings. This suggests reduced efficiency of neuro-integrative mechanisms operating at a perceptual level in autism. These results are in line with the idea that visual atypicalities mediated by intermediate-scale neural networks emerge before or during the school-age period in autism.
authors.affiliation: University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Montreal, Quebec, Canada ; Centre de Recherche en Neuropsychologie et Cognition (CERNEC) and Department of Psychology, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Jessica B
authors.initials: JB
authors.lastname: Rivest
authors.forename: Boutheina
authors.initials: B
authors.lastname: Jemel
authors.forename: Armando
authors.initials: A
authors.lastname: Bertone
authors.forename: Michelle
authors.initials: M
authors.lastname: McKerral
authors.forename: Laurent
authors.initials: L
authors.lastname: Mottron
mesh_terms: D001321:Autistic Disorder / Q000503:physiopathology*; D002648:Child; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000503:physiopathology; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology*