An effect that counts: Temporally contiguous action effect enhances motor performance.

An action-effect temporal contiguity holds essential information for motor control. Emerging accounts suggest that the temporally contiguous action effect is rewarding in and of itself, further promoting the development of motor representations and reinforcing the selection of the relevant motor program. The current study follows these theoretical and empirical indications to directly investigate the promoting impact of action effect temporal contiguity on motor performance. In two experiments, participants rapidly moved toward a target location on a computer monitor and clicked on the target with their mouse key as quickly and accurately as possible. Their click response triggered a perceptual effect (a brief flash) on the target. To examine the impact of action-effect delay and its temporal contiguity context, we manipulated action-effect delay in two temporal contiguity contexts-long versus short lag conditions. The findings demonstrate that the temporally contiguous perceptual effect enhances motor performance as indicated by end-point precision and movement speed. In addition, a substantial impact of the temporal contiguity context was observed. Namely, we found enhanced motor performance after an ambiguous (300 ms) action-effect delay sampled from short compared to long lag distributions (Experiment 1). This pattern was inconclusive for an immediate action effect (Experiment 2). We discuss the findings in the context of reinforcement from action effect and movement control.