Sensory over‐responsivity and atypical neural responses to socially relevant stimuli in autism.

Although aversive responses to sensory stimuli are common in autism spectrum disorder (ASD), it remains unknown whether the social relevance of aversive sensory inputs affects their processing. We used functional magnetic resonance imaging (fMRI) to investigate neural responses to mildly aversive nonsocial and social sensory stimuli as well as how sensory over‐responsivity (SOR) severity relates to these responses. Participants included 21 ASD and 25 typically‐developing (TD) youth, aged 8.6–18.0 years. Results showed that TD youth exhibited significant neural discrimination of socially relevant versus irrelevant aversive sensory stimuli, particularly in the amygdala and orbitofrontal cortex (OFC), regions that are crucial for sensory and social processing. In contrast, ASD youth showed reduced neural discrimination of social versus nonsocial stimuli in the amygdala and OFC, as well as overall greater neural responses to nonsocial compared with social stimuli. Moreover, higher SOR in ASD was associated with heightened responses in sensory‐motor regions to socially‐relevant stimuli. These findings further our understanding of the relationship between sensory and social processing in ASD, suggesting limited attention to the social relevance compared with aversiveness level of sensory input in ASD versus TD youth, particularly in ASD youth with higher SOR. Lay Summary: In this study, we used functional magnetic resonance imaging (fMRI) to examine brain responses to aversive sensory stimuli with and without social relevance in youth with autism spectrum disorder (ASD) and typically‐developing (TD) youth. TD youth showed greater neural responses to social compared with nonsocial sensory inputs, whereas the opposite was true in ASD youth. Results suggest that compared with TD youth, ASD youth (particularly those with more severe sensory over‐responsivity symptoms) attend more to the level of aversiveness rather than to the social relevance of sensory input. [ABSTRACT FROM AUTHOR]