Reward sensitivity and corticostriatal function during social rewards

Aberrant levels of reward sensitivity (RS) have been linked to substance use (SU) disorder and are characterized by alterations in reward processing in the ventral striatum (VS). Less is known about how RS and subclinical SU relate to striatal function during social rewards (e.g., positive peer feedback). Testing this relation is critical towards predicting risk for development of SU disorder. In this pre-registered study, participants (N=44) underwent fMRI while completing well-matched tasks that assess neural response to reward in social and monetary domains. Contrary to our hypotheses, aberrant RS blunted the relationship between SU and striatal activation during receipt of rewards, regardless of domain. Moreover, exploratory whole-brain analyses showed unique relations between SU and social rewards in temporoparietal junction. Psychophysiological interaction (PPI) analysis demonstrated that aberrant RS is associated with increased connectivity between the VS and ventromedial prefrontal cortex during social rewards. Finally, we found that SU was associated with decreased connectivity between the VS and dorsomedial prefrontal cortex for social rewards, independent of RS. These findings demonstrate nuanced relations between RS and SU, even among those without SU disorder, and suggest altered reward-related engagement in cortico-VS as potential predictors of developing disordered behavior.