We assessed hemisphere function in right-handed male chronic schizophrenic patients using dichotic listening tests. We evaluated digit, tonic and transitional tests in patients with paranoid schizophrenia (n = 8), patients with disorganized schizophrenia (n = 8) and in control subjects (n = 8). The dichotic listening analysis discriminated between paranoid and disorganized schizophrenia. In disorganized schizophrenia, functional impairment of both hemispheres was demonstrated, while in paranoid schizophrenia dysfunction was more prominent in the right hemisphere. These results indicate the possible involvement of right hemisphere dysfunction in the pathophysiology of chronic paranoid schizophrenia, in contrast to dysfunction of both hemispheres in chronic disorganized schizophrenia.
