Sensory information flows from the periphery through different stages of processing in the central nervous system, to the thalamus and cerebral cortex. Within the cerebral cortex, feedforward processing is strongly modulated by top-down "feedback", with impacts on perception and decision making. The computations performed by individual neurons and networks of neurons within each region transform incoming information to produce an output that is projected to other targets in the brain. This course explores the local circuit mechanisms underlying the representation and refinement of sensory information at successive stages of the feedforward processing pathways. We will focus on the formation of receptive field properties within individual neurons, including contributions of feedforward circuitry and interactions between neurons within local circuits, and on how populations of neurons work together to encode information. An important theme of the course will also be to learn about current methodology in systems neuroscience research to study and perturb circuits. Descriptions of such experiments will be incorporated into lectures, and we will also read several primary research articles relevant to the major themes of the course.