Localisation Of Function Of The Brain

Question 1

Localisation versus holistic theory

Answer 1

• Idea that different parts of the brain perform different tasks and are involved with different parts of the body
• if an area of the brain becomes damaged the function associated with that area will be affected

Question 2

Hemispheres of the brain

Answer 2

• the main part of the brain = cerebrum, is divided into 2 symmetrical halves called the left adn right hemispheres
• some of the physical and psychological functions are controlled or dominated by a particular hemisphere, called lateralisation
• activity on the left-hand side of the body is controlled by the right hemisphere and vice versa

Question 3

Lobes of the brain

Answer 3

The cerebral cortex is the outer layer of both hemispheres
- cortex of both hemisphere is divided into 4 centres: frontal lobe, parietal lobe, occipital lobe and temporal lobe.

Question 4

Motor area

Answer 4

• at the back of the frontal lobe is the motor area
• controls the voluntary movement in the opposite side of the body
• damage to this area may result in loss of control of fine movements

Question 5

Somatosensory

Answer 5

• at the front of both parietal lobes is the somatosensory area
• separated from the motor area by the central sulcus
• where the sensory information from the skin is represented

Question 6

Visual area is

Answer 6

• in the occipital lobe is the visual area
• each eye sends information from the right visual field to the left visual cortex vise versa
• means that damage to the left hemisphere can produce blindness in the right visual field of both eyes

Question 7

Auditory area

Answer 7

• temporal lobes house the visual area
• analyses speech-based information
• damage may produce partial hearing loss.
• the more extensive the damage the more extensive the loss

Question 8

Language centres of the brain

Answer 8

• damage to Bronchas area: slow speech lacking in fluency
• people with Brochas aphasia: difficulty with prepositions
• wernikes area: in the left temporal lobe, responsible for language understanding
• wernikes aphasia: nonsense words

Question 9

Evaluation - strength

Answer 9

Evidence from neurosurgery:
- damage to areas of the brain have been linked to mental disorders
- Dougherty et al - 44 people with OCD who had undergone a cingulotomy. At post surgical follow up, 30% had successful responses to the surgery.
- the success of the procedures suggest that beh associated with serious mental disorders may be localised.

Question 10

Strength

Answer 10

Evidence from brain scans:
- brain scans support the idea that everyday brain functions are localised
- Peterson et al - used brain scans to demonstrate how Wernikes area was active during listening tasks and Broncha’s area was active during reading task
- semantic and episodic memories reside in different parts of the prefrontal cortex
- provide scientific evidence that many brain functions are localised

Question 11

Limitation

Answer 11

Language localisation questioned:
- language may not be localised just to Bronchas and wernikes area
- language function is distributed more holistically in the brain
- language streams identified across the cortex e.g. the thalamus a subcortical region
Suggests that rather than bring confined to a few areas, language may be organised more holistically