Abstract
The effects of aging on hemispheric specialization in verbal and visuo-spatial functions were examined by dichotic listening and tactile recognition tests. In the first experiment, thirty aged (65-91 year) intact subjects and university students were tested by a dichotic listening tape with pairs of two-syllable meaningful words. The results revealed an overall decline of scores in the aged subjects but there was no interaction between subject and the degree of right ear advantage. In the second experiment, subjects were asked to judged whether successively presented nonsense tactile stimuli to each hand were identical or not. Reaction times and accuracy rates of each hand of the aged subjects were inferior to those of the control subjects. However, no interaction was found between hand and subject group. Both experiments show that there is no evidence to suggest any selective deterioration or specialization of hemispheric function in the aged people, though overall performance level declines with age, which may be caused by short-term memory deficit.
