Reward processing in autism

TLDR

The social‑motivation hypothesis proposes that autistic infants find social stimuli unrewarding, potentially leading to downstream deficits, yet direct neural evidence of social reward processing has been lacking. This study used fMRI to compare social and monetary rewarded implicit learning in children with ASD and typically developing peers. Sixteen ASD and sixteen matched TD males performed two rewarded implicit learning tasks while brain activity was recorded, enabling analysis of reward‑related circuitry and its link to social development. ASD participants exhibited reduced neural responses to both social and monetary rewards—especially social—along with a frontostriatal deficit during social learning, and ventral striatum activity correlated with social reciprocity in TD children, supporting the hypothesis that diminished social reward processing underlies social learning impairments in ASD.

Abstract

Abstract The social motivation hypothesis of autism posits that infants with autism do not experience social stimuli as rewarding, thereby leading to a cascade of potentially negative consequences for later development. While possible downstream effects of this hypothesis such as altered face and voice processing have been examined, there has not been a direct investigation of social reward processing in autism. Here we use functional magnetic resonance imaging to examine social and monetary rewarded implicit learning in children with and without autism spectrum disorders (ASD). Sixteen males with ASD and sixteen age‐ and IQ‐matched typically developing (TD) males were scanned while performing two versions of a rewarded implicit learning task. In addition to examining responses to reward, we investigated the neural circuitry supporting rewarded learning and the relationship between these factors and social development. We found diminished neural responses to both social and monetary rewards in ASD, with a pronounced reduction in response to social rewards (SR). Children with ASD also demonstrated a further deficit in frontostriatal response during social, but not monetary, rewarded learning. Moreover, we show a relationship between ventral striatum activity and social reciprocity in TD children. Together, these data support the hypothesis that children with ASD have diminished neural responses to SR, and that this deficit relates to social learning impairments.