Roger Wolcott Sperry

Roger Wolcott Sperry (August 20, 1913 – April 17, 1994) was an American neurobiologist and Nobel Prize winner.

Roger Sperry
Born	Roger Wolcott Sperry August 20, 1913 (2009-08-20) Hartford, Connecticut
Died	April 17, 1994 (1994-04-18) (aged 80) Pasadena, California
Alma mater	Oberlin College University of Chicago (PhD)
Known for	Split-brain research Chemoaffinity hypothesis
Awards	Nobel Prize in Physiology or Medicine (1981)
Scientific career
Fields	Neuropsychology
Thesis	Functional results of crossing nerves and transposing muscles in the fore and hind limbs of the rat (1941)
Doctoral advisor	Paul A. Weiss
Website	rogersperry.org

He shared the 1981 Nobel Prize in Physiology or Medicine with David Hubel and Torsten Wiesel. In 1989, Sperry also received the National Medal of Science.

Before Sperry's experiments, some research evidence seemed to indicate that areas of the cerebral cortex were largely interchangeable. In his early experiments, Sperry showed that the opposite was true: after early development, circuits of the brain are largely hardwired. That is, they are set with a particular function.

Sperry's work was on 'split-brain' research. In his Nobel-winning work, Sperry tested ten patients who had undergone an operation developed in 1940 by William Van Wagenen, a neurosurgeon in Rochester, NY.

The surgery, designed to treat epileptics with grand mal seizures, severed (cut) the corpus callosum, the area of the brain used to transfer signals between the right and left hemispheres.

Sperry and his colleagues tested these patients with tasks that were known to be dependent on specific hemispheres of the brain and demonstrated that the two halves of the brain may each contain consciousness. In his words, each hemisphere is

indeed a conscious system in its own right, perceiving, thinking, remembering, reasoning, willing, and emoting, all at a characteristically human level, and . . . both the left and the right hemisphere may be conscious simultaneously in different, even in mutually conflicting, mental experiences that run along in parallel

— Roger Wolcott Sperry, 1974

This research contributed greatly to understanding how each cerebral hemisphere works.

Some activities, such as naming objects or putting blocks together in a particular way, can only be done when using one side of the brain or the other. It seems the left hemisphere usually specializes in language processes and the right is dominant in visual-construction tasks.