Figure 1. Working Hypothesis.

A1: In a reaching task, the timing of task-end is synchronized with the end of body movement. The efficiency of visuomotor adaptation peaks immediately after movement-end (which is equivalent to the task-end), and diminishes uniformly with visual feedback delay. B1: In a shooting task, a ball hits a target some time after the shooter’s arm movement is complete; therefore, the timing of task-end is dissociated from the timing of movement-end. Our working hypothesis was that visuomotor adaptation should not exhibit peak efficiency immediately after movement-end, but at task-end (the time of impact). In other words, we predicted that efficiency would not diminish uniformly with delayed feedback.