Lateral inhibition in the autism spectrum: an SSVEP study of visual cortical lateral interactions

Circuit level brain dysfunction has been suggested as a common mechanism through which diverse genetic risk factors and neurobiological sequelae lead to the core features of autism spectrum disorder (Geschwind 2009; Port et al. 2014). An important mediator of circuit level brain activity is lateral inhibition, and a number of authors have suggested that lateral inhibition may be atypical in ASD. However, evidence regarding putative atypical lateral connections in ASD is mixed. Here we employed a steady state visual evoked potential (SSVEP) paradigm to further investigate lateral connections within a group of high functioning adults with ASD. At a group level, we found no evidence of altered lateral interactions in ASD. Exploratory analyses reveal that greater ASD symptom severity (increased ADOS score) is associated with increased short range lateral inhibition. These results suggest that lateral interactions are not altered in ASD at a group-level, but that subtle alterations in such neurobiological processes may underlie the heterogeneity seen in the autism spectrum in terms of sensory perception and behavioural phenotype.