Question

7. Illustration: Experiments with “split-brain” patients: Independent variable: visual field (V.F.), and thus the side of the brain that a stimulus is presented to . Dependent variables: naming the stimulus and recognizing the stimulus (two different tasks).

A)What does the patient do when the word “key” is flashed to EACH visual field? Can the patient name the word, and can he recognize it touch, when presented to each visual field?

B) Explain why he can/ can’t do each of the two tasks with each side of the brain

Answer 1

The split-brain syndrome refers to a condition characterized by a cluster of neurological abnormalities arising from the partial or complete lesioning of the corpus callosum. It is also called callosal disconnection syndrome. The corpus callosum consists of about 200 million axons that interconnect the right and left hemispheres of the brain.

The primary function of the corpus callosum is to integrate motor, sensory, and cognitive performances between the cerebral cortex on one side of the brain to the same region on the other side. Consequently, after the split brain surgery when the person is asked to say what the image was, the left hemisphere speaks. The reason is that the left hemisphere, which receives information from the right half of each eye, also houses the speech centres. But when allowed to gesture with a hand, the right hemisphere points to the image that it saw. The reason is that the right hemisphere can’t speak; however, it can still control one hand.