Reduced visual evoked potential amplitude in autism spectrum disorder, a variability effect?

• Published in: Translational psychiatry 2019-12, Vol.9 (1), p.341-9, Article 341
• Main Authors: Kovarski, Klara, Malvy, Joëlle, Khanna, Raoul K., Arsène, Sophie, Batty, Magali, Latinus, Marianne
• Format: Article
• Language: English
• Subjects: 631/378; 692/699/476/1373; Autism; Autism Spectrum Disorder - physiopathology; Behavioral Sciences; Biological Psychology; Child; Child, Preschool; Cognitive science; Electroencephalography; Evoked Potentials, Visual - physiology; Female; Humans; Male; Medicine; Medicine & Public Health; Neuroscience; Neurosciences; Pattern Recognition, Visual - physiology; Pharmacotherapy; Psychiatry; Psychology
• ISSN: 2158-3188; 2158-3188
• DOI: 10.1038/s41398-019-0672-6

Atypical sensory behaviours represent a core symptom of autism spectrum disorder (ASD). Investigating early visual processing is crucial to deepen our understanding of higher-level processes. Visual evoked potentials (VEPs) to pattern-reversal checkerboards were recorded in ASD children and age-matched controls. Peak analysis of the P100 component and two types of single-trial analyses were carried out. P100 amplitude was reduced in the ASD group, consistent with previous reports. The analysis of the proportion of trials with a positive activity in the latency range of the P100, measuring inter-trial (in)consistency, allowed identifying two subgroups of ASD participants: the first group, as control children, showed a high inter-trial consistency, whereas the other group showed an inter-trial inconsistency. Analysis of median absolute deviation of single-trial P100 (st-P100) latencies revealed an increased latency variability in the ASD group. Both single-trial analyses revealed increased variability in a subset of children with ASD. To control for this variability, VEPs were reconstructed by including only positive trials or trials with homogeneous st-P100 latencies. These control analyses abolished group differences, confirming that the reduced P100 amplitude results from increased inter-trial variability in ASD. This increased variability in ASD supports the neural noise theory. The existence of subgroups in ASD suggests that the neural response variability is not a genuine characteristic of the entire autistic spectrum, but rather characterized subgroups of children. Exploring the relationship between sensory responsiveness and inter-trial variability could provide more precise bioclinical profiles in children with ASD, and complete the functional diagnostic crucial for the development of individualized therapeutical projects.