THE NEURAL BASIS OF REWARD-DRIVEN ENHANCEMENT OF WORKING MEMORY PERFORMANCE
Reward anticipation affects cognitive performance, including working memory (WM). However, the neural processes underlying cognitive effort deployment based on the expected reward value remain unexplored. Here we addressed this question by measuring the behavioural and neural effect of monetary incentives on visual WM performance in young adults using functional magnetic resonance imaging (fMRI). At the beginning of each experimental trial, a cue indicated whether small or large monetary reward could be earned. The behavioural results revealed significantly higher WM performance in trials where high monetary reward was anticipated than in the low reward condition. The brain’s task-positive and task-negative networks showed increased and decreased fMRI responses on high reward trials, respectively. Importantly, the magnitude of the reward effect in several brain regions—including the middle and inferior frontal gyrus, putamen, and globus pallidus—showed a close association with the size and dynamics of the reward-induced enhancement of working memory performance. These findings imply a key role for the fronto-striatal circuit in the motivational control of cognitive effort deployment during execution of working memory tasks depending on the expected reward value.