The emergence of action-effect-related motor adaptation amidst outcome unpredictability

Previous research indicates that quick, repetitive actions (pinches, taps, button presses) are executed with smaller force when followed by predictable and salient action effects (tones, light flashes). It has been suggested that successive actions become gradually softer until an optimum is reached, which presumably reflects a balance between the ability to maintain a high probability of action success, and the reduction of exerted force to conserve energy. In the present experiments, we investigated whether this