Is P50 suppression a measure of sensory gating in schizophrenia?

Yi Jin,William E Bunney,Curt A Sandman,Julie V Patterson,Kirsten Fleming,Jeffrey R Moenter,Amir H Kalali,William P Hetrick,Steven G Potkin

doi:10.1016/s0006-3223(98)00115-2

Yi Jin, William E Bunney + Show 7 more

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https://doi.org/10.1016/s0006-3223(98)00115-2

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Abstract

Background: Abnormal P50 response has been hypothesized to reflect the sensory gating deficit in schizophrenia. Despite the extensive literature concerning the sensory filtering or gating deficit in schizophrenia, no evidence has been provided to test the relationship of the P50 phenomenon with patients’ experiences of perceptual anomalies. Methods: Sixteen drug-free DSM-IV diagnosed schizophrenic patients who reported moderate to severe perceptual anomalies in the auditory or visual modality were examined as compared to 16 schizophrenic patients who did not report perceptual anomalies, and 16 normal subjects. Both control groups were age- and gender-matched with the study group. Results: Patients reporting perceptual anomalies exhibited P50 patterns that did not differ from normal subjects. In contrast, patients who did not report perceptual anomalies showed the abnormal P50 ratios previously found to be associated with schizophrenia. Conclusions: These paradoxical findings do not support the hypothetical relationship between the P50 and behavioral measures of sensory gating, suggesting that additional studies are needed to further explore the clinical correlates of the P50.

Highlights

Patients with schizophrenia have difficulty in processing sequentially presented sensory stimuli (Adler et al 1982; Freedman et al 1983; Nuechtertlein and Dawson 1985; Braff et al 1995; Shagass 1977)
Schizophrenic patients who reported perceptual anomalies exhibited P50 ratios that did not differ from normal controls
Patients who did not experience perceptual anomalies, had P50 ratios that were significantly different from normal controls and similar to responses previously observed in groups of schizophrenics (Adler et al 1982; Freedman 1983, 1987; Baker et al 1990)

Summary

Introduction

Patients with schizophrenia have difficulty in processing sequentially presented sensory stimuli (Adler et al 1982; Freedman et al 1983; Nuechtertlein and Dawson 1985; Braff et al 1995; Shagass 1977). In contrast to normal persons, a subgroup of schizophrenic patients were unable to filter out irrelevant stimuli, resulting in perceptual abnormalities. Weckowicz and Blewett reasoned that the cognitive defects observed in schizophrenia were secondary to the impairment of the sensory filter In their classic paper, McGhie and Chapman (1961) described clinical observations of 26 schizophrenic cases as support for the theory of abnormal filtering of sensory input in schizophrenia. They observed that patients with schizophrenia had difficulty concentrating, decreased ability to focus on external sensory stimuli, and a hyperawareness of background noises.

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