right Brain/Left Brain: Cerebral specialization

Question 1

What is the purpose of split-brain research?

Answer 1

In split-brain surgery, the bundle of fibers that connects the cerebral hemispheres
(the corpus callosum) is cut to reduce the severity of epileptic seizures.

Question 2

What is contralateral innervation?

Answer 2

Each hemisphere’s primary connections are to the opposite side of the body. Thus, the left hemisphere controls, and communicates with, the right hand, right arm, right leg, right eyebrow, and so on. In contrast, the right hemisphere controls, and communicates with, the left side of the body.

Question 3

What are the exceptions to contralateral innervation?

Answer 3

Vision and hearing are more complex.

Both eyes deliver information to both hemispheres, but input is still separated. Stimuli in the right half of the visual field are registered by receptors on the left side of each eye, which send signals to the left hemisphere. Stimuli in the left half of the visual field are transmitted by both eyes to the right hemisphere.

Auditory inputs to each ear also go to both hemispheres. However, connections to the opposite hemisphere are stronger or more immediate. That is, sounds presented to the right ear are registered in the left hemisphere first, while sounds presented to the left ear are registered more quickly in the right hemisphere.

Question 4

Why isn’t the asymmetrical nature of the brain always aparent?

Answer 4

For the most part, people don’t notice this asymmetric, “crisscrossed” organization
because the two hemispheres are in close communication with each other. Information received by one hemisphere is readily shared with the other via the corpus callosum.

Question 5

What did split-brain research reveal?

Answer 5

The right hemisphere has its own special talents. The right hemisphere to be better than the left on a variety of visual-spatial tasks, including discriminating colors, arranging blocks, and recognizing faces.

Question 6

What functions are superior in the left hemispheres? 5

Answer 6

The left hemisphere is usually better on tasks involving:

1. verbal processing, such as:
2. language,
3. speech,
4. reading, and
5. writing.

Question 7

What functions are superior to the right hemisphere? 4

Answer 7

The right hemisphere exhibits superiority on many tasks involving

1. nonverbal processing, such as
2. most spatial,
3. musical, and
4. visual recognition tasks (including the perception of emotions).