NEUROPHYSIOLOGICAL EVIDENCE FOR A DEFECT IN NEURONAL MECHANISMS INVOLVED IN SENSORY GATING IN SCHIZOPHRENIA

  • 1 January 1982
    • journal article
    • research article
    • Vol. 17  (6) , 639-654
Abstract
The action of CNS inhibitory neuronal mechanisms was tested in acutely psychotic unmedicated schizophrenic patients and in normal controls. An early positive component of the auditory average evoked response recorded at the vertex 50 ms after a click stimulus was studied. Stimuli were delivered at 10-s intervals to establish a baseline response. Inhibitory mechanisms were then tested in a conditioning-testing paradigm by assessing the change in response to a 2nd stimulus following the 1st at either 0.5, 1.0 or 2.0-s intervals. At the 0.5-s interval, normal controls had a > 90% mean decrement in response, whereas schizophrenics showed a < 15% mean decrement. At 2-s intervals, responses from normals were still 30-50% diminished, but those from schizophrenics showed an increased response to the stimulus compared to baseline. The data suggest that normally present inhibitory mechanisms are markedly reduced in schizophrenics. Failure of these inhibitory mechanisms may be responsible for the defects in sensory gating which are thought to be an important part of the pathophysiology of schizophrenia.