Calibration and alignment are separable: Evidence from prism adaptation

In 2 prism adaptation experiments, the authors investigated the effects of limb starting position visibility (visible or not visible) and visual feedb ack availability (early or late in target pointing movements). Thirty-two s tudents participated in Experiment 1 and 24 students participated in Experi ment 2. Independent of visual feedback availability, constant error was lar ger and variable error was smaller for target pointing when. limb starting position was visible during prism exposure. Independent of limb starting po sition visibility, aftereffects of prism exposure were determined by visual feedback availability. Those results support the hypothesis that calibrati on is determined by limb starting position visibility, whereas alignment is determined separately by visual feedback availability.