title: Different mechanisms of ipsilateral and contralateral ear extinction in aphasic patients.
abstract: Dichotic listening performance was studied in 35 aphasic patients with unilateral brain lesions. Within this group, 30 patients exhibited an abnormal ear discrepancy: 20 patients showed a left-ear advantage (right-ear extinction), and 10 patients showed a right-ear advantage (left-ear extinction). All subjects were given a number of verbal tasks in order to evaluate several aspects of their linguistic abilities. For the left-ear advantage group, verbal scores were positively related to left-ear scores, but not to right-ear scores. For the right-ear advantage group, verbal scores were positively related to both left- and right-ear scores. The present results lend partial support for the prediction that right-ear extinction is associated with damage to the temporal lobe involving the geniculo-temporal system. No support was found for the prediction that left-ear extinction is associated with lesions placed in the deep structures of the parietal or parieto-occipital lobe involving the corpus callosum system. Our data indicate that the initial severity of brain injury is a critical factor in determining the direction of ear extinction, the lesions being larger in the left-ear advantage group. Results are discussed in relationship to other explanations of ipsilateral and contralateral extinction in aphasic patients.
authors: Department of Clinical Psychology, Free University, Amsterdam, The Netherlands.
authors: A
authors: A
authors: Bouma
authors: B J
authors: BJ
authors: Ansink
mesh_terms: D000328:Adult; D000368:Aged; D001037:Aphasia / Q000523:psychology*; D001288:Attention; D001925:Brain Damage, Chronic / Q000523:psychology; D004007:Dichotic Listening Tests; D004292:Dominance, Cerebral; D005108:Extinction, Psychological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013067:Speech Perception