Split-brain patients are individuals who have undergone a corpus callosotomy, a surgical procedure where the corpus callosum, which connects the two hemispheres of the brain, is severed. This procedure is typically a last resort to treat severe epilepsy when pharmaceutical treatments have failed. By cutting the connection between the hemispheres, epileptic activity is contained to one side of the brain, reducing the severity and frequency of seizures.
After the surgery, each hemisphere can function independently, leading to some unusual behaviors. For example, a blindfolded split-brain patient may be unable to name an object held in their left hand because the information from the left hand goes to the right hemisphere, which typically has a weaker language center. Similarly, they might struggle to execute verbal commands with their left hand. In some instances, conflicting actions might occur, such as one hand buttoning a shirt while the other unbuttons it. However, such conflicts are rare, and one hemisphere usually overrides the other. Despite these challenges, many split-brain patients retain intact memory and social skills and can maintain motor skills learned before the surgery, like walking or swimming.