Functional Connectivity During Social Reward Processing in Autistic and Neurotypical Adolescents

A core diagnostic feature of autism is atypical social interaction. Reduced social motivation is proposed to underlie these differences. However, empirical neuroimaging studies testing this hypothesis have shown mixed support and have been limited in their ability to understand real-world social-interactive processes in autism.

To address these limitations, we acquired functional MRI data from neurotypical and autistic youth (n = 86, 15 females) during a "live" chat that elicits social reward processes. We examined task-evoked functional connectivity (FC) of regions associated with reward and mentalizing processes within the broader social reward circuitry.

Task-evoked FC between social reward regions was significantly modulated by social interaction and receipt of social-interactive reward. Compared to neurotypical peers, autistic youth showed significantly greater task-evoked connectivity between posterior temporal regions associated with mentalizing and the amygdala, a key node in the reward network. Furthermore, across groups, the connectivity strength between these regions was negatively correlated with self-reported social motivation and reward during the scanner task.

These findings highlight an important role of FC within the broader social reward circuitry for social-interactive reward. We suggest that greater context-dependent FC (i.e., differences between social and non-social reward) may indicate an increased "neural effort" or hypersensitivity to social feedback that relates to reduced social reward within autistic and neurotypical adolescents. These findings are important because, counter to prevailing theories, they show that greater neural connectivity during social reward during adolescence may confer risk for poor social outcomes.