The objectives of the proposed research are 1) to learn how visual information is processed and coded in the central nervous system and 2) to understand the effects of early experience on the development of the visual system. A number of studies of the receptive-field properties and afferent connectivity of cells in different layers of normal and deprived cat extra striate visual cortex are proposed (areas 18, 19, and LS). These will provide information about the effects of early experience on cortical development as well as about the functional significance of cortical lamination. These studies will also provide some information about the projections of different classes of geniculate cells (W,X,Y) to different layers of extra-striate cortex. In order to carry out the proposed studies, neuroanatomical (horseradish peroxidase histochemistry, autoradiography) as well as electrophysiological (single unit recordings, electrical stimulation) techniques will be employed. This type of multidisciplinary approach is necessary to related structure and function in the nervous system.