A split-brain patient can verbalize the name of the object that she is holding in her left hand. True False
The correct answer and explanation is:
Correct Answer: False
A split-brain patient is someone who has undergone a surgical procedure known as corpus callosotomy, in which the corpus callosum—the bundle of nerve fibers connecting the two cerebral hemispheres—is severed. This procedure is usually done to treat severe epilepsy. As a result, the left and right hemispheres of the brain can no longer communicate directly with each other.
Each hemisphere of the brain controls and processes sensory input and motor output for the opposite (contralateral) side of the body:
- The left hemisphere controls and receives input from the right hand.
- The right hemisphere controls and receives input from the left hand.
Importantly, for most people, the left hemisphere houses the language centers (such as Broca’s area and Wernicke’s area), which are responsible for speech production and comprehension.
So, when a split-brain patient holds an object in her left hand, that sensory information is processed by the right hemisphere. However, since the right hemisphere cannot communicate with the left hemisphere (which has the language centers), the patient cannot verbally name the object. She might be able to use her left hand to point to a matching picture or demonstrate the use of the object, but she will not be able to say the name of the object out loud.
In contrast, if the object is placed in the right hand, the information goes to the left hemisphere, and the patient can easily verbalize the object’s name.
This phenomenon provides strong evidence for hemispheric specialization—especially the role of the left hemisphere in language—and helps us understand how brain lateralization affects behavior and cognition.