Sensory gating deficits in schizophrenia: can we parse the effects of medication, nicotine use, and changes in clinical status?

Schizophrenia is a disorder characterized by core deficits in information processing and attentional mechanisms. Abnormalities in the neural substrates associated with the filtering or 'gating' of sensory information are among the most consistent findings in schizophrenia research. Intact gating and inhibitory mechanisms are necessary in order to navigate successfully in a stimulus-laden world, and to selectively attend to salient stimuli and ignore redundant, repetitive, or trivial information. An individual's gating functioning can be assessed via self-report measures and/or using laboratory-based psychophysiological paradigms such as P50 event-related potential suppression and prepulse inhibition (PPI). In this paper, the literature on gating deficits across the schizophrenia spectrum and the reported effects of nicotine and medications on P50 suppression and PPI is reviewed. In addition, productive strategies for 'parsing' specific medication effects on P50 suppression and PPI deficits and directions for future research that would enable us to answer residual questions about the functional correlates of these abnormalities in schizophrenia patients are discussed. (C) 2003 Elsevier Science B.V. All rights reserved.