The neural substrates responsible for reward sensitivity association with delay discounting: left dorsal anterior...

Delay discounting refers to the tendency to devalue rewards as the delay to their receipt increases. Reward sensitivity, defined as an individual's responsiveness to rewarding stimuli, has been suggested to influence delay discounting behavior. However, the neural mechanisms underlying this association remain largely unexplored. In the present study, we investigated the neural basis of the relationship between reward sensitivity and delay discounting using voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) analyses. Behaviorally, reward sensitivity was positively correlated with delay discounting, indicating that individuals with higher reward sensitivity tend to favor immediate rewards over delayed ones. Structurally, VBM analysis revealed that reward sensitivity was positively associated with gray matter volume in the dorsal anterior cingulate cortex (dACC). Moreover, RSFC results showed a negative correlation between reward sensitivity and functional connectivity between the dACC and the precuneus. Importantly, this functional connectivity partially mediated the relationship between reward sensitivity and delay discounting. These findings suggest that the functional connectivity between the dACC and the precuneus may serve as a neural pathway through which reward sensitivity influences delay discounting, offering new insights into the neural mechanisms underlying individual differences in intertemporal decision-making.