An operation that is performed in severe cases of epilepsy, in which the corpus callosum is cut, separating the cerebral hemispheres and usually lessing the severity of grand mal seizures.

In 1963, neurosugeons Joseph Bogen and Phillip Vogel found that patients with severe eplipsy could be helped by severing the corpus callosum. In this way, the pulsing waves of neural activity that occur during a seizure could be confined to one hemisphere rather than spreading across the corpus callosum and involving the entire brain.

Research with split-brain patients has expanded the knowledge of the unique capabilities of the individual hemispheres.

In 1968 Roger Sperry found that when the brain was surgically seperated, each hemisphere continued to have invidual and private experiences, sensations, thoughts, and perceptions. Most sensory experiences, however, are shared almost simultaneously because each ear and eye has direct sensory connectons to both hemispheres.

Also called callotomy. See also: