Roger Wolcott Sperry

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.

Sperry would just sit at the end of the table and listen to Stetson and his colleagues discuss their research and other psychological interests.

[13] In 1952, he became the Section Chief of Neurological Diseases and Blindness at the National Institutes of Health and finished out the year at the Marine Biology Laboratory in Coral Gables, Florida.

He was not offered tenure at Chicago and planned to move to Bethesda, Maryland but was held up by a delay in construction at the National Institutes of Health.

Under the supervision of Paul Weiss while earning his Ph.D. at the University of Chicago, Sperry became interested in neuronal specificity and brain circuitry and began questioning the existing concepts about these two topics.

After repeated tests Sperry found that the rats never learned to lift up the correct paw, leading him to the conclusion that some things are just hardwired and cannot be relearned.

"[16] During Sperry's postdoctoral years with Karl Lashley at Harvard and at the Yerkes Laboratories of Primate Biology in Orange Park, Florida, he continued his work on neuronal specificity that he had begun as a doctoral student and initiated a new series of studies involving salamanders.

The question was whether vision would be normal after regeneration or would the animal forever view the world as "upside down" and right-left reversed.

Restoration of normal vision (i.e., "seeing" the world in a "right-side-up" orientation) would mean that the regenerating nerves had terminated in new sites, quite different from the original ones.

These studies, which provided strong evidence for nerve guidance by "intricate chemical codes under genetic control" (1963) culminated in Sperry's chemoaffinity hypothesis (1951).

[15] Sperry later served on the Board of Trustees and as Professor of Psychobiology Emeritus at California Institute of Technology.

Sperry's research with "split-brain" cats helped lead to the discovery that cutting the corpus callosum is a very effective treatment for patients who suffer from epilepsy.

This observation rendered the question: if the surgery had absolutely no effect on any part of the patients' normal functioning then what is the purpose of the corpus callosum?

Working with his graduate student Michael Gazzaniga, Sperry invited several of the "split-brain" patients to volunteer to take part in his study to determine if the surgery affected their functioning.

In the first series of tests, Sperry would present a word to either the left or right visual field for a short period of time.

These tests proved that when the corpus callosum is severed, it breaks the connection between the left and right hemispheres, making them unable to communicate with each other.

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 parallelThis research contributed greatly to understanding the lateralization of brain function.

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 neuronsIn 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.

[19] The experiments conducted by Sperry focused on four major ideas which were also called "turnarounds": equipotentiality, split brain studies, nerve regeneration and plasticity, and psychology of the consciousness.