split brain

n. Any brain in which the cerebral hemispheres have been partially disconnected by cutting the corpus callosum, which is the largest of the three major connections between the two sides of the cortex. A few humans have had surgery to accomplish this in order to forestall severe epileptic seizures, which increase each time they cross the corpus callosum. It has also been done in numerous laboratory animals, in order to study the mostly independent functioning of the two halves of the cerebral cortex.