Attention is an integral component of information processing. A pronounced attention deficit exists among people with schizophrenia and their first-degree relatives as compared to persons without this pathology. Schizophrenics demonstrate marked deficiencies on psychophysical tasks that require temporal and / or spatial integration, properties that are associated with the two primary visual pathways composed of magnocellular (M) and parvocellular (P) cells, respectively. The deficit expresses itself as a dysfunctional information processing system that affects higher order processes, for example, perceptual ability and memory. The focus of this review is to integrate results from several divergent areas of research to include those studies that identify the contributions of the M and P pathways associated with information processing and the attention deficit. The diverse approaches reviewed in this chapter converge to provide a neurophysiologic explanation of the attention deficit in schizophrenia.