Attentional deficit is one of the root causes of the cognitive dysfunction and general impairments in information processing that are characteristic of persons afflicted with schizophrenia. When compared to the performance of normal adults, schizophrenia patients show pronounced deficits on psychophysical tasks requiring the allocation and/or maintenance of attention on behaviorally relevant information. Attention deficits in schizophrenia have been measured using a multitude of task and stimulus parameters. Many of these studies converge on the finding that the marked deficit in attention observed in schizophrenia patients may be related to a dysfunction within the neurophysiological visual pathways at an anatomically and temporally early stage of visual processing. Various psychophysical tasks have been used in order to evaluate processing deficits in the magnocellular and parvo-cellular visual pathways of schizophrenia patients. As a result, it has been proposed that schizophrenia is associated with preferential magnocellular/dorsal stream dysfunction. This project will utilize electrophysiological and functional neuroimaging measures of neural activity in order to delineate the neuroanatomical and temporal bases of selective visual attention deficits in schizophrenia patients and, in particular, how these relate to sensory processing within the magnocellular and parvo-cellular visual pathways.