Poster B29, Sunday, March 25, 8:00-10:00 am, Exhibit Hall C
Enhancement of action inhibition by accidental rewards preceding the stop signals
Hsin-Ju Lee1, Fa-Hsuan Lin2, Wen-Jui Kuo1; 1National Yang-Ming University, 2National Taiwan University
In this study, we were interested in the effects of accidental rewards, both positive and negative, on the implementation of action inhibition and their neural underpinnings. For the purpose, a stop-signal task was used together with fMRI, and there were three accidental rewards arranged to match the stop trials of the task, including monetary gain (positive), monetary loss (negative), and neutral feedback. We found that the stop signal reaction time (SSRT) was shorter in both positive and negative reward conditions, as compared to the neutral one. It appears that emotional fluctuation perturbed by the positive and negative rewards might facilitate action inhibition control. For the imaging results, we discovered that positive reward was encoded in the ventral striatum and negative reward elicited higher activity in the lateral orbitofrontal cortex. We also found that the brain regions associated with inhibitory control were enhanced, echoing the improved efficiency of stopping processes. Pre-SMA showed higher activation when participants were receiving both reward feedbacks, whereas right posterior inferior frontal cortex showed an interaction of reward feedback and inhibitory control. Strikingly, the striatum activity revealed a functional dorsal-ventral gradient. While the dorsal striatum displayed more substantial activation when participants were perturbed by the positive and negative rewards, the ventral striatum activity was only higher for the positive reward.
Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control