Asymmetries in Hemispheric Control of Attention in Schizophrenia.
WASHINGTON UNIV ST LOUIS MO
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In this report, we compare the performance of schizophrenic patients with normal control subjects in their ability to direct visual attention. Investigators have long suggested that schizophrenia might be related to an impairment in the regulation of attention. In the first experiment, patients were distinguished from controls by a slower response to a target in the right visual field than to a target in the left visual field when attention was not first directed to the target location. In the second experiment, patients were distinguished from controls by a stronger bias in favor of symbolic information over language information about spatial direction. In both experiments, the patients demonstrated deficits in attention similar to patients from previous studies who had unilateral lesions of the left hemisphere. The identification of performance abnormalities using tasks which are simple, have dissectable cognitive components, have been related to discrete neural systems, and control for non-specific variables provide the basis for constructing reasonable hypotheses about the cognitive psychology and functional neuroanatomy of schizophrenia.