L7 - Lateralisation Of Function

Question 1

What is Lateralisation of Function?

Answer 1

• Both hemispheres have different specialisations
• Right is responsible for the LHS of the body, and vice versa
• Left hemisphere is more dominant for language (contains Broca’s and Wernicke’s Area)
• Right hemisphere is more dominant for recognising faces
• Both hemispheres are connected by a bundle of nerve fibres called the Corpus Callosum

Question 2

Evaluation Of Lateralisation of Function (+/-)

Answer 2

+ Increases neural processing capacity which is adaptive. By using one hemisphere, it leaves the other to engage in another function. A study found that lateralisation in chickens is associated with an ability to perform 2 tasks simultaneously

• JW developed the capacity to speak using his right hemisphere. JW could speak about informations regardless which hemisphere it was presented to. Shows that there are individual differences in how the brain functions

Question 3

What is Split Brain Research?

Answer 3

• Surgeons cut the corpus callosum to prevent violent electrical activity caused by epileptic seizures crossing hemispheres. Patients who underwent this surgery are called split brain patients.
• Information from the left visual field goes to the right hemisphere and vice versatile. As the corpus callosum has been cut, information given to one hemisphere cannot travel to the other.

Question 4

What was the process of Split Brain Research?

Answer 4

• Patients stare at a dot in the centre of a screen and information is presented in the left or right visual field. They are asked to make responses with either hand or verbally without being able to see what their hands do.
• e.g if a pic of a dog is flashed in their right visual field, they will be able to answer dog because it had gone to their left hemisphere where the language centres are. If it was in their left visual field they would be able to draw it with the their left hand as there is no language centres in the right hemisphere.

Question 5

Evaluation of Split Brain Research (-)

Answer 5

• These studies have very few participants, making the results hard to generalise
• IRL, a severed corpus callosum can be compensated for by the unrestricted use of both visual fields, so research lacks ecological validity
• The disconnection between hemispheres is greater in some patients than others, and some patients have drug therapy for epilepsy for much longer than others which could affect the way their brain works. This means findings cannot be generalised