Corpus Callosum Anatomy

The corpus callosum connects the left and right cerebral hemispheres of the brain. Most communication between regions in different halves of the brain are carried over the corpus callosum.

In the olden days, patients with extreme cases of epilepsy underwent surgery to remove the corpus callosum so to restrict epileptic fits (or ‘storms’ as they are sometimes termed) to one side of the brain, lessening, or sometimes inhibiting completely, the overall seizure. After their operation, patients were still able to walk and talk, with little or no impairments of intelligence or emotion but developed some strange side effects.

The result of the surgery essentially left the patients with two minds. One patient reported that she would go to her wardrobe for clothes and her two hands selected two diferent items of clothing and attempted to dress her simultaneously. A study by Robert Sperry found that if blindfolded patients picked up an object, they could only come up with the name of an object if it was in their right hand, not if it was in their left.

Since the left side of the brain typically controls language, and the operation of the right side of the body, the patients were able to speak the name of the object while they were feeling it in their right hand. If the patients held something in their left hand, the right brain was essentially feeling and understanding what the object was but could not communicate with the left brain through the corpus callosum to provide the name using the left brain’s language area.