ABSTRACT
The main purpose of this chapter is to report how blind subjects differ from blindfolded sighted subjects in their estimation of short and long targets while making linear and curvilinear movements. These differences were studied on the basis of the implications of a motor program theory that holds that short movements are programmed and long ones depend on feedback. Two experiments were conducted to examine if a visual reference system helps sighted individuals in performing better than blind individuals on short targets. The difference between the two groups was studied using location, distance, and simple reproduction cues. It was found that errors of the sighted group were less than those of the blind group on simple reproduction and location cues. However, errors of the sighted group increased on long targets of the distance task. It was also found that on long targets blind subjects performed better than sighted subjects who, in contrast, were better on short targets, irrespective of the effects of cues. It was also shown how errors of blind and sighted groups were found equal for the curvilinear movements with distance cues.
