| Abstract: | 16 depressed patients, 16 schizophrenic patients, and 16 normal controls (20–50 yrs old) were given 2 dichotic listening tests and 2 cognitive tests at intervals ranging from patients' initial hospitalization to recovery. Repeated-measures ANOVA revealed that severely depressed Ss failed to obtain normal ear-superiority in either dichotic test; however, normal superiorities emerged with recovery from depression. Schizophrenic Ss initially failed to show normal right-ear superiority on a dichotic-words test but did obtain the expected left-ear advantage on a dichotic-chords test. Following treatment, schizophrenics shifted from a left-ear to a right-ear advantage in dichotic chords and also increased (although not significantly) their right-ear advantage in dichotic words. Both patient groups showed normal word-fluency but impaired spatial ability, which did not improve with recovery. Results suggest that both depression and schizophrenia are associated with a breakdown in the process of interhemispheric inhibition that mediates perceptual asymmetry. In depression, treatment returned Ss' normal patterns of asymmetry, whereas in schizophrenia, treatment created an abnormal pattern of asymmetry that may have reflected the allocation of both verbal and nonverbal material to the left hemisphere. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
