hemispheric lateralisation

Question 1

hemispheric lateralisation

Answer 1

The 2 hemispheres of the human brain are not exactly alike.
They are functionally different, and certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other.
For example, language which is lateralised to the left hemisphere.
Information from the left side of the body is processed in the right hemisphere and information from the right side of the body is processed in left hemisphere.

Question 2

Broca

Answer 2

Broca established that damage in a particular area of the left hemisphere led to language problems, but the same was not true for damage in the right hemisphere.

Question 3

corpus callosum

Answer 3

A bundle of nerve fibres that connects the 2 hemispheres, therefore information received by one hemisphere can be sent to the other hemisphere.

Question 4

AO3 - strength

Answer 4

Researchers used PET scans to identify which brain areas were active during a visual processing task.
When participants were asked to look at global elements of an image, regions of the right hemisphere were more active.
When asked to focus on the finer details, regions of the left hemisphere were more dominant. Supports idea that the hemispheres are functionally different.

Question 5

AO3 - strength

Answer 5

There is evidence that in domestic chickens, brain lateralisation is associated with an enhanced ability to perform 2 tasks simultaneously - finding food and being vigilant for predators.
This finding does provide some evidence that brain lateralisation enhances brain efficiency in cognitive tasks that demand the simultaneous but different use of both hemispheres.

Question 6

AO3 - limitation

Answer 6

It is generally assumed that the main advantage of brain lateralisation is that it increases neural processing capacity.
By only using one hemisphere to engage in a particular task, this would leave the other hemisphere free to engage in another activity.
However, despite this assumption, very little empirical evidence has been provided to show that lateralisation gives any advantage to the functioning of the brain.

Question 7

AO3 - limitation

Answer 7

Researchers discovered a patient who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere, which eventually gave the ability to speak about information presented to either side of the brain. This suggests that perhaps lateralisation is not fixed and that the brain can adapt following damage to certain areas.