Perceptual asymmetries in schizophrenia: subtype differences in left hemisphere dominance for dichotic fused words

Friedman MS, Bruder GE, Nestor PG, Stuart BK, Amador XF, Gorman JM

New York State Psychiatric Institute and College of Physicians & Surgeons, Columbia University, New York, USA

Received November 13, 2000; revised April 17, 2001; accepted May 3, 2001

Abstract

Objective: Dichotic listening techniques have been used to study hemispheric dominance for language in schizophrenia. The authors' goal was to compare subjects with paranoid and undifferentiated subtypes of schizophrenia.
Methods: The Fused Rhymed Words Test was used to compare perceptual asymmetries in 16 patients with paranoid schizophrenia, 28 patients with undifferentiated schizophrenia, and 29 healthy comparison subjects.
Results: Patients with paranoid schizophrenia had the largest left hemisphere advantage and patients with undifferentiated schizophrenia had the smallest. The asymmetry of healthy subjects was intermediate. Hemisphere advantage varied as a function of gender only in the patients with undifferentiated schizophrenia.
Conclusions: The findings support the hypotheses that undifferentiated schizophrenia is associated with underactivation of left hemisphere resources for verbal processing and that paranoid schizophrenia is characterized by preserved left hemisphere processing.