Dichotic word-perception of aphasic and normal subjects.

The present investigation examined the role of the right cerebral hemisphere in linguistic perception following a left cerebral insult which had resulted in aphasia. Auditory dichotic procedures were utilized to investigate the ear-preferences of 30 aphasic Ss, grouped relative to the amount of time since the onset of left cerebral insult, and a group of 10 normal control Ss. An oral-response task and a pointing-response task were given. Statistical analyses showed a significant left-ear preference for aphasic Ss who were more than 6 mo. post-cerebral insult; however, Ss less than 6 mo. post-cerebral insult did not demonstrate a significant ear-preference under auditory dichotic stimulation. In contrast, a significant right-ear preference was noted for the normal controls. Significant differences were not shown for the aphasic or control groups on the oral and pointing tasks.