Autistic children show reduced activity in left superior temporal cortex in response to social-emotional meaning in language.

Autistic children often differ from non-autistic peers in social interaction, emotional processing, and language communication. While the neural differences between autistic and non-autistic children in processing paralinguistic social-emotional cues, such as emotional prosody, are well-documented, much less is known about how the brain processes the social-emotional meaning carried by the language content itself. In non-autistic adults, the left superior temporal sulcus (STS) and adjacent gyrus show a social-emotional bias, responding more strongly to social-emotional content than to content describing inanimate objects. We investigated whether this bias is present in children and whether it is altered in autistic children. We recruited 78 right-handed children who underwent functional magnetic resonance imaging (fMRI) scanning while listening to sentences describing either people in emotional situations (social-emotional sentences) or non-human objects, events, or concepts (object sentences). After excluding those with excessive head motion, we analyzed data from 58 of them (37 autistic and 21 non-autistic; mean age 10 years). Across the sample as a whole, the left STS responded more strongly to social-emotional sentences than to object sentences, indicating that this social-emotional bias is already present in childhood. Importantly, this bias was reduced in autistic children compared to non-autistic controls, whereas no group difference was observed in general auditory or lexico-syntactic processing. This reduced activity in the left STS in response to social-emotional semantics may contribute to autistic children's social communication challenges.