People ARE Split-Brained! Roger Sperry was born August 20, 1913, in Hartford Connecticut. He was a psycho-biologist who was awarded the Nobel Prize in physiology and medicine in 1981 for his 40 years of research on the brain. He was the one who discovered that the human brain has different specialized functions on the right and left sides, and that they could operate practically independently.
Sperry and his colleagues conducted several experiments on a patient who had epilepsy who had the "bridge" (a nerve bundle) between the left and right hemispheres of the brain split so the connection was severed. This part of the brain is called the corpus callosum. During the experiment that doctors found that this patient often had trouble naming different objects or putting blocks together, which could only be done when using one side of the brain.
To perform this experiment, Sperry would give certain stimulus to the side of the body opposite to the brain hemisphere being tested.
This was done because the right side of the body connects to the left-brain, and the left side of the body connects to the right-brain. For Sperry and his team, it seemed that the left hemisphere of the brain was specialized in language and the right was specialized for visual and constructive tasks.
One other experiment they performed was geared toward people who had undergone split-brain surgery. He asked the patients to focus on the center of a divided screen. Then he flashed the word key on the left side, and the word ring on the left side. The patients said that the only word they saw was the word "ring," and completely denied the presence of the other word, "key." This experiment proved that the right hemisphere cannot verbalize information, such as the word "key",