Progress in pharmacologic and behavioral treatments for schizophrenia depends in part on developing new and valid approaches for assessing cognitive dysfunction. Specialized behavioral measures are required to characterize the integrity of specific cognitive mechanisms in persons with schizophrenia. The overall aims of this project are to develop efficient batteries for assessment of early auditory and visual research deficits in schizophrenia. In the auditory system, patients show reliable deficits on behavioral measures such as tone matching (TMT) and distorted tunes (DTT) task identification, which correlate with disturbance in generation of ERP components such as mismatch negativity (MMN) and auditory N1. Basic deficits in tone matching, moreover, upward generalize to produce deficits in such "real world" processes as auditory emotion identification, phonological reading analysis and phonemic identification. In the visual system, patients show reliable deficits in ability to detect low contrast, low spatial frequency stimuli, which correlate with disturbances in generation of ERP components such as steady-state VEP, and transient visual P1, particularly to low spatial frequency (magnocellular selective) stimuli. Deficits in early visual processing contribute to impairment in higher order processes such as perceptual closure and reading. For both auditory and visual systems, patterns of dysfunction correspond to predictions of NMDA models of schizophrenia. Narrative Schizophrenia is a major neuropsychiatric disorder that affects approximately 1% of the population worldwide. Cognitive dysfunction represent a core component of schizophrenia and a major cause of chronic disability. In addition to other cognitive deficits, individuals with schizophrenia have difficulty in the processing of sensory information such as matching tones following brief delay or recognizing certain types of visual stimuli. These low-level deficits interfere with patient's ability to perform more complex tasks, such as identifying emotions when other's speak to them, or recognizing pictures when they are only able to see fragments of the overall image. These abnormalities can be measured both behaviorally and by measuring "brain waves" while patients are listening to tones or looking at pictures. This project will develop standardized approaches to analyze sensory deficits in schizophrenia. [unreadable] [unreadable] [unreadable]