Dynamic Hemispheric Imbalance in Schizophrenia

Abstract

In a study of forty-eight unmedicated recent hospital admissions diagnosed as schizophrenic with the help of the Present State Examination (PSE) (Wing, Cooper and Sartorious, 1974) lateral asymmetries in electrodermal orienting responses were found in either direction (Gruzelier & Manchanda, 1982). Classification of patients according to the nature of the asymmetry and comparison of their symptoms and signs on the PSE and Brief Psychiatric Rating Scale (BPRS) (Overall & Gorham, 1962) delineated two syndromes, one representing positive symptoms and the other negative symptoms (see Gruzelier ‘Lateral imbalance and positive and negative symptoms’ in this collection). From consideration of the electrodermal lateral asymmetry, reciprocal interactions between the hemispheres in the control of arousal, and the character of the behaviour described in the syndromes, e.g. pressure of speech in one and restricted quantity of speech in the other, it was inferred that the positive syndrome reflected hemispheric imbalance in the direction of overactivation of the left hemisphere and the negative syndrome overactivation of the right hemisphere.