Abstract
When performing many common manual tasks, people's eye movements appear to be well coordinated with the movements of their hands. People readily learn to intercept a moving target with a cursor even if the cursor is delayed with respect to the hand by about 200ms. With such a delay, the position of the cursor is dissociated from that of the hand. We here examine how such adaptation influences eye-hand coordination. We recorded eye movements while subjects tried to intercept targets that were moving in different directions at different velocities. The experiment had 4 phases that differed in the feedback that was provided about the on-going movement of the hand. In the first phase they had full vision of the hand. In the second phase they had no visual information about the hand's movement. In the third (adaptation) phase they saw a cursor representing the hand. The fourth phase was identical to the second. During the adaptation phase we increased the delay between the hand and the cursor by 1ms on each trial until the delay was 200ms. When subjects could see their hand they hit the target with their hand. When feedback was removed they intercepted the target's path about 100ms ahead of the target. When a cursor represented the hand, they hit the target with the cursor, despite the delay, so that for large delays the hand passed even further ahead of the target. When the cursor was removed the hand gradually returned to crossing the target's path about 100ms before the target. In all cases the eyes simply pursued the target. In the adaptation phase the eyes continued to follow the target after the hand had crossed its path, presumably to obtain accurate feedback about the outcome of the movement.
Meeting abstract presented at VSS 2017