Roger Wolcott Sperry, Nobel Prize in Physiology or Medicine, 1981

http://en.wikipedia.org/wiki/Roger_W._Sperry

Roger Wolcott Sperry (August 20, 1913 – April 17, 1994) was a neuropsychologist, neurobiologist and Nobel laureate who, together with David Hunter Hubel and Torsten Nils Wiesel, won the 1981 Nobel Prize in Medicine for his work with split-brain research.

Sperry was born in Hartford, Connecticut, to Francis Bushnell and Florence Kraemer Sperry. His father was in banking, and his mother trained in business school. Roger had one brother, Russell Loomis. Their father died when Roger was 11. Afterwards, his mother became assistant to the principal in the local high school.

Sperry went to Hall High School in West Hartford, Connecticut, where he was a star athlete in several sports, and did well enough academically to win a scholarship to Oberlin College. At Oberlin, he was captain of the basketball team, and he also took part in varsity baseball, football, and track; he received his bachelor's degree in English in 1935 and a master's degree in psychology in 1937. He received his Ph.D. in zoology from the University of Chicago in 1941, supervised by Paul A. Weiss. Sperry then did post-doctoral research with Karl Lashley at Harvard University.

In 1942, he began work at the Yerkes Laboratories of Primate Biology, then a part of Harvard University. He left in 1946 to become an assistant professor, and later associate professor, at the University of Chicago. In 1952, he became the Section Chief of Neurological Diseases and Blindness at the National Institutes of Health. In 1954, he accepted a position as a professor at the California Institute of Technology (Caltech) where he performed his most famous experiments with his then student Michael Gazzaniga.

Before Sperry's experiments, some research evidence seemed to indicate that areas of the brain were largely undifferentiated and interchangeable. In his early experiments, Sperry showed that the opposite was true: after early development, circuits of the brain are largely hardwired.

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 intractable grand mal seizures, involves severing 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 the lateralization of brain function. In 1989, Sperry also received the National Medal of Science.

In addition to his contribution in establishing the lateralized function of the brain, Sperry is also noted for his chemo affinity theory, which has been not only influential in formation of testable hypotheses in how precise neuronal wiring diagram is established in the brain, but the hypothesis itself has been verified by numerous experiments.

"The cells and fibers of the brain must carry some kind of individual identification tags, presumably cytochemical in nature, by which they are distinguished one from another almost, in many regions, to the level of the single neurons"

—Roger Wolcott Sperry

In the words of a 2009 review article in Science magazine: "He suggested that gradients of such identification tags on retinal neurons and on the target cells in the brain coordinately guide the orderly projection of millions of developing retinal axons. This idea was supported by the identification and genetic analysis of axon guidance molecules, including those that direct development of the vertebrate visual system." This was confirmed in the seventies by Marshall W. Nirenberg's work on chick retinas and later on Drosophila melanogaster larvae.

In 1949, Sperry married Norma Gay Deupree. They had one son, Glenn Michael, and one daughter, Janeth Hope. At the time he received the Nobel Prize, he was suffering from advanced stage Kuru, a neurodegenerative disease acquired through contact with human brains.