Split Research & Hemispheric Lateralisation

Question 1

Hemispheric lateralisation:

Answer 1

The idea that each hemisphere (half) of the brain is mainly responsible
for certain behaviours, processes and activities. This is in contrast with the holistic theory of brain
function, which suggests that function is distributed across the whole brain.

Question 2

Split Brain Research:

Answer 2

Series of studies than began in the 1960s (still ongoing) involving epileptic people who experienced a surgical separation of the hemispheres of the brain. Investigates the extent to which brain function is lateralised.

Question 3

How does vision work?

Answer 3

1. Each visual field has two sides left and right. The right hemisphere controls the left side of the body, and vice versa.
2. In the occipital lobe, nerve impulses are transferred from the retina to the visual cortex via optic nerves.
3. Therefore, information which we receive from the left visual field is processed
   by the right hemisphere, which then coordinates a response to affect the left side of the body.

Question 4

Sperry’s Split Brain Studies:

Answer 4

1. 1968 studies all 11 had undergone a commissurotomy, in which the corpus callosum and other tissues which connect the 2 were cut down the middle.
2. This has been done to control frequent and severe epileptic seizures.
3. The main communication line between the 2 hemispheres was removed.
4. Allowed them to see the extent to which the 2 hemispheres were specialised and whether they were performed independent to each other.