Interpretation of outcome on dichotic listening tests following stroke

The historical basis for interpretation of the dichotic listening performance of aphasic patients is presented. Most studies agree with respect to outcome; aphasic patients as a group tend to have ear advantages (EAs) that are shifted to the left relative to non-brain-damaged listeners. Studies disagree as to whether this difference reflects a shift toward right hemisphere dominance for language processing or a "contralateral ear lesion effect." Emphasis is placed on the most recent additions to the literature, including discussion of factors that affect the accuracy with which lesions can be localized. The conclusion reached is that variables other than dominance determine the direction of ear advantage for many aphasic listeners.