Reward modulates cortical representations of action

People are capable of rapid on-line improvements in performance when they are offered a reward. The neural mechanism by which this performance enhancement occurs remains unclear. We investigated this phenomenon by offering monetary reward to human participants, contingent on successful performance in a sequence production task. We found that people performed actions more quickly and accurately when they were offered large rewards. Increasing reward magnitude was associated with elevated activity throughout the brain prior to movement. Multivariate patterns of activity in these reward-responsive regions encoded information about the upcoming action. Follow-up analyses provided evidence that action decoding in pre-SMA and other motor planning areas was improved for large reward trials and successful action decoding was associated with improved performance. These results suggest that reward may enhance performance by enhancing neural representations of action used in motor planning.