ABNORMAL FUNCTIONAL LATERALIZATION OF THE SENSORIMOTOR CORTEX IN PATIENTS WITH SCHIZOPHRENIA

PREVIOUS neuroimaging studies have suggested that patients with schizo phrenia fail to recruit appropriate focal patterns of cortical respons es to cognitive tasks. We investigated whether patients with schizophr enia show a normal focal response to a simple motor task. Seven strong ly right-handed patients with schizophrenia and seven strongly right-h anded normal subjects performed motor tasks of increasing complexity. Patients were unable to recruit as focal a response even to a simple, automatic sequential finger movement task. They showed greater ipsilat eral activation in the primary sensorimotor and lateral premotor regio ns and had a significantly lower laterality quotient than normal subje cts. These phenomena increased with the complexity of the task. These results demonstrate a functional disturbance in the cortical motor cir cuitry of patients with schizophrenia.