Cerebral asymmetries: neuropsychological measurement and theoretical issues

Abstract

First this paper reviews methodological issues in the study of right brain/left brain functions; and then discusses a model of integrated brain functioning. This integrated brain model has implications for schizophrenia and creativity. Measures of right and left brain functioning are: Behavioral measures of lateralization; neuropsychological test batteries; tachistoscopic presentations; dichotic listening tasks; verbal and performance sub-tests of intelligence tests; standardized measures of verbal and visual functions; gaze as a measure of hemispheric dominance. Individual characteristics of these measures are explored. A theory of the integrated brain is presented which includes both hemispheres as part of an organized information processing system. Hypotheses are drawn from this model. The model suggests that schizophrenia is the disorganization of information processing between two hemispheres and between the cortex and sub-cortical regions. In contrast, creativity is the exchange of excitatory and inhibitory stimulation between both hemispheres. Complex problem solving and the 'aha' phenomena, are examples of integrated brain functioning. Research paradigms to test these hypotheses are discussed.