Basal ganglia activity mirrors a benefit of action and reward on long-lasting event memory

Abstract

The expectation of reward is known to enhance a consolidation of long-termmemory for events.We tested whether this effect is driven by positive valence or action requirements tied to expected reward. Using a functional magnetic resonance imaging (fMRI) paradigmin young adults, novel images predicted gain or loss outcomes,which in turnwere either obtained or avoided by action or inaction. After 24 h, memory for these images reflected a benefit of action aswell as a congruence of action requirements and valence, namely, action for reward and inaction for avoidance. fMRI responses in the hippocampus, a region known to be critical for long-term memory function, reflected the anticipation of inaction. In contrast, activity in the putamen mirrored the congruence of action requirement and valence, whereas other basal ganglia regions mirrored overall action benefits on longlasting memory. The findings indicate a novel type of functional division between the hippocampus and the basal ganglia in the motivational regulation of long-term memory consolidation, which favors remembering events that are worth acting for.