ADAPTATION TO GRADUAL AS COMPARED WITH SUDDEN VISUO-MOTOR DISTORTIONS

If visual feedback is discordant with movement direction, the visuo-mo tor mapping is disrupted, but can be updated with practice. In this ex periment subjects practiced discrete arm movements under conditions of visual feedback rotation. One group was exposed to 10 degrees-step in crements of visual feedback rotation up to a total of 90 degrees, a se cond group to a 90 degrees visual feedback rotation throughout the exp eriment. After the first group reached the 90 degrees visual feedback rotation, its subjects performed faster, with less spatial error, and showed larger aftereffects than the subjects who practiced constantly under the 90 degrees visual feedback rotation condition. Results sugge st that gradually increasing feedback distortion allows more complete adaptation than a large, sudden distortion onset.