Unraveling neural adaptation to vocal and non-vocal sounds in autism

Abstract

Autism is characterized by a need for sameness but also by difficulties in social communication and interaction. These two aspects have been related at the neural level to atypicalities in change detection as assessed with the mismatch negativity as well as by an atypical brain response to voice. It has been proposed that MMN atypicality could be the consequence of a deficit in neural adaptation, but to date no study has formally characterized neural adaptation in this population. The aim of the present study was i) to characterize neural adaptation in autistic adults with a suitable Roving paradigm and ii) to evaluate the influence of social and emotional prosodic information on neural adaptation using vocal and non-vocal, and neutral and emotional sounds. Neural adaptation was measured in a group of autistic and non-autistic adults in a Roving paradigm with sounds repeated 4, 8 or 14 times. Neural adaptation was found to be atypical and unstabilized in autistic for both nature of sounds with an adaptation to vocal while not for non-vocal sounds. These findings provide better understanding the symptomatology of autism related to atypicalities in adaptation stemming from the need for sameness, as well as the impact of emotional content on socio-communicative impairments.