Sensory gating and inhibitory function in late-life schizophrenia.

Although similarities between the cognitive deficits observed in schizophrenia and those observed in aging have been recognized for over 50 years, little work has been done to directly examine these similarities or their implications for late-life schizophrenia. We review studies of prepulse inhibition, habituation, latent inhibition, and negative priming that indicate marked similarities in the patterns of deficits observed in schizophrenia and in aging. We also present new data from preliminary studies of prepulse inhibition and negative priming in which we compare young normal controls, older adult normal controls, and late-life schizophrenia patients. For both measures, both schizophrenia patients and older adults showed an inhibitory deficit relative to young controls. In the case of negative priming, older schizophrenia patients showed evidence of greater inhibitory dysfunction than did normal older adults, suggesting that older schizophrenia patients suffer a deficit resulting from the combined effects of schizophrenia and aging. The implications of these results and directions for future research are discussed.