SIGNIFICANCE OF UNILATERAL EAR EXTINCTION ON THE DICHOTIC-LISTENING TEST

The association between unilateral ear extinction on the dichotic list ening test and the lateralization of epileptogenic foci was examined i n a sample of 49 seizure patients undergoing preoperative evaluation f or epilepsy surgery. Results from patients who were left hemisphere do minant for speech indicated that right ear impairment was always predi ctive of a unilateral left hemisphere focus, but left ear extinction w as associated with unilateral lesions of either hemisphere. In this pa tient sample, dichotic listening performance reflected an interaction of both lateralized foci and hemispheric preference of language proces sing. Implications concerning clinical use of the dichotic listening t est are discussed.