Biography of William T . Newsome

T he processing of visual information by the brain is a complex task. Identifying the neural mechanisms that underlie visual perception and vision-based decision-making has been the research focus of William T. Newsome over the past 30 years. Elected to the National Academy of Sciences in 2000, Newsome explains that ‘‘perceptual experience is constructed from streams of action potentials’’ in the central nervous system’s 3 million optic nerve fibers (www.hhmi.org research investigators newsome.html). This is to say that, although our tendency is to trust our vision implicitly, the cerebral cortex actually has no direct experience of the visual world. What sets Newsome’s research apart from many other studies in this area is that the techniques he uses—primarily, stimulation of brain areas of primates with microelectrodes—have helped demonstrate cause and effect rather than merely show a correlation between behavior and activity of the brain. Says Newsome, ‘‘We show that by imposing these artificial signals by stimulating the cells with electric current, we cause predictable changes in performance.’’