Reward sensitivity modulation of brain activity during response inhibition

This work investigated the relationship between individual differences in reward sensitivity and the activity of brain regions involved in response inhibition. Participants ( n  = 51, 20 females) performed a stop-signal task while undergoing fMRI scanning. Inhibition of dominant responses during the task was associated to activation of bilateral anterior insula. Parameter estimates from these activation clusters were extracted to run an ROI analysis. Reward sensitivity, as measured by the Sensitivity to Reward (SR) scale from the SPSRQ (Torrubia et al., 2001), was negatively correlated with activity in right anterior insula. A whole-brain correlation analysis was also conducted, in which SR scores were negatively correlated with activity in the anterior cingulate cortex and the left supramarginal gyrus. These results suggest that individual differences in reward sensitivity may involve differences in cognitive processing that are manifested as distinct patterns of brain activation, even in the absence of explicit reward contingencies.