Abstract
Developments in television technology have made possible new approaches to the study of the role of visual feedback in motor control. In two experiments using a special videodisc recording and playback system, the effects of delaying for 66 msec a subject’s view of his own hand during a target-directed movement were investigated. The observed effects of such visually delayed feedback compared to spatially distorted feedback produced by prisms led to three major conclusions: (a) despite the behavioral similarity (overshooting) induced by the two kinds of altered feedback, the role of each in the visual motor control loop is different; (b) adaptation to and the aftereffect of the two kinds of altered feedback are based on different control mechanisms; (c) the processing and use of visual information in hand control requires less time than previous experiments have indicated.