Schizophrenia--an emotional hypersensitivity of the right cerebral hemisphere

While modern neuropsychological and electrophysiological studies claim a functional disturbance of the left hemisphere (LH) in schizophrenia, historical clinical and anatomical work rather points to the right hemisphere (RH) as the main site of psychosis. In the light of an interhemispheric functional balance of inhibition and release, LH-dysfunction in schizophrenia could be interpreted as a consequence of an overactive and inhibiting RH. Since the RH is especially activated by emotional stimuli, and exaggerated distractability and sensitivity to emotional stimuli are hallmarks of schizophrenia, we compared the emotional irritability of the RH and LH in 35 acute schizophrenics and 22 matched controls. Using tachistoscopic half-field presentation we found in acute schizophrenics a selective impairment of RH-function with simultaneous improvement of LH-performance induced by emotional distractors. We therefore suggest that a right hemispheric dysfunction and hypersensitivity to emotional material plays an essential catalytic role in acute schizophrenia.