Summary: William Newsome's research focuses on the neural mechanisms underlying visual perception, visually based decision making, and related issues in cognitive neuroscience. He seeks to understand how higher mammals acquire sensory information about the world, how that information is processed within the brain, and how behavioral responses to that information are organized.

The cerebral cortex has no direct experience of the visual world. Rather, our perceptual experience is constructed from streams of action potentials in the 3 million optic nerve fibers that project from the two retinas to the central nervous system. After a relay synapse in the visual portion of the thalamus, visual information reaches a hierarchically organized network of more than 30 visual areas within the occipital, temporal, and parietal lobes of the cerebral cortex. Ultimately, neural processing within these cortical areas results in visual perception and multiple forms of visually based cognition such as attention, short-term memory, and decision making.

We are interested in several questions: How is information about the external world encoded in streams of action potentials? What is the functional significance of neurons in the visual cortex that respond selectively to stimulus orientation, direction of motion, stereo disparity, or color? How is the information carried by cortical neurons interpreted, or "read out," so as to inform behavioral decisions? How are decisions influenced by internal brain states related, for example, to the animal's anticipation of rewards?