Comparison of four components of sensory gating in schizophrenia and normal subjects: a preliminary report

Dysfunction of sensory gating has been implicated in the pathophysiology of schizophrenia. The goal of this study was to provide evidence that sensory gating dysfunction in schizophrenia patients is a compounded problem with difficulty in filtering out irrelevant input and filtering in relevant inpu t at both an early-preattentive stage and a later, early-attentive stage of information processing. Four components of sensory gating were examined in 12 medicated, stable schizophrenia patients and 12 age- and sex-matched no rmal control subjects. Evoked potential paradigms designed to examine the e ffects of stimulus repetition and stimulus change were utilized. Attenuatio n of the amplitude of the P50 and the N100 evoked potentials with stimulus repetition was significantly decreased in schizophrenia patients as compare d to normal control subjects. The presentation of deviant stimuli caused th e degree of attenuation to decrease in normal subjects. This effect was muc h decreased (and at times reversed) in schizophrenia subjects. These data s uggest that schizophrenia patients have difficulty inhibiting incoming, irr elevant stimuli and responding to incoming, significant input as measured b y preattentive EPs (P50). The data also suggest that similar abnormalities can be demonstrated at a slightly later phase of information processing (i. e. early-attentive phase) using the N100 EP. (C) 1999 Elsevier Science Irel and Ltd. All rights reserved.