Reward strengthens action–effect binding

According to ideomotor theory, anticipatory representations of action consequences are the basis for voluntary action control. A previous study suggested that rewards strengthen the acquisition of action effect links and hence ideomotor learning. Participants in our experiments (total N = 231) first learned to associate 4 manual actions with unique sound effects. Two sound effects were additionally predictive of a monetary reward. In a subsequent test phase, the former sound effects were presented as response primes in a speeded reaction time task. Response times were higher when the primes preceded a response other than the one to which they were linked in the preceding learning phase, an index of response−effect learning. Response priming was stronger for previously rewarded actions. Critically, this effect was not observed in a control condition with previously punished actions that produced a monetary loss. Overall, the results suggest that relations to rewarding consequences enhance associations between actions and sensory effects, a process that may facilitate reinforcement learning.