brain: localisation of function

Question 1

what is localisation of function?

Answer 1

where specific parts of the brain are associated and responsible for particular physical and psychological functions

Question 2

what is the motor area and what happens if it is damaged?

Answer 2

it is located at the back of the frontal lobe. it controls voluntary movement in the opposite side of the body.
DAMAGE: may result in loss of control over fine movement

Question 3

what is the somosensory area?

Answer 3

it is located at the front of the parietal lobe. it is where sensory information from the skin is represented. the amount of somosensory area allocated to a particular area denotes its sensitivity.

Question 4

what is the visual area and what happens if it is damaged?

Answer 4

located in the occipital lobe. each eye sends information from the right visual field to the left visual cortex and from the left visual field to the left visual cortex.
DAMAGE: the left hemisphere can cause blindness in the right visual field of the eye

Question 5

what is brocas area and what happens if it is damaged?

Answer 5

it is responsible for speech production
DAMAGE: brocas aphasia- speech that is slow and lacks fluency.

Question 6

what is wernikes area and what happens if it is damaged?

Answer 6

it is responsible for language comprehension.
DAMAGE; wernikes aphasia- producing nonsense words in speech.

Question 7

what does the frontal lobe control?

Answer 7

movement of the body
personality
concentration
speech
problem solving

Question 8

what does the temporal lobe control?

Answer 8

receives and processes sound
recognises faces
emotions
long term memory

Question 9

what does the Brain stem control?

Answer 9

breathing
heart rate
temperature

Question 10

what does the cerebellum control?

Answer 10

motor skills
balance
coordination

Question 11

what does the occipital lobe control?

Answer 11

sight

Question 12

what does the parietal lobe control?

Answer 12

touch and pressure
taste
body awareness

Question 13

AO3: how is ‘research evidence’ a strength to localisation of function?

Answer 13

One strength of localisation is that there is research evidence to support the idea that brain functions are localised. For example, the case of Phineas Gage showed that following an accident that damaged his frontal lobe, Gage’s personality changed and he became more short-tempered and aggressive. In addition, offenders with anti-social personality disorder suffer with reduced activity in the prefrontal cortex of the brain. This evidence supports localisation of function as the case suggests that our frontal lobe is responsible for personality and regulating mood. Therefore, it is likely that our physical and mental functions are localised to some extent which increases the validity of this theory.
However, the Phineas Gage case study was from 1848, so how do we know that this is true. Therefore, it has low reliability and validity as how do we know how well the people who commented on his change in behaviour knew him before the accident, and how do we know if the change in behaviour was due to damage and not from trauma of the event.

Question 14

AO3: how is ‘brain scanning’ a strength to localisation of function?

Answer 14

One strength of localisation is that there is brain scanning evidence to support the idea that brain functions are localised. For example, Petersen et al (1988) used brain scanning techniques and found that Wernicke’s area was most active during a listening task, whereas, Broca’s area was most active during a reading task. This evidence supports localisation of function as it provides scientific evidence that each parts of the brain have higher functioning levels when doing different activities, suggesting that specific functions are performed in specific areas. Therefore, it is likely that our speech and language comprehension areas are localised to some extent, increasing the scientific status of this theory.

Question 15

AO3: how is ‘real life application’ a strength to localisation of function?

Answer 15

One strength of localisation is that it has real life application to support the idea that brain functions are localised. For example, removing or destroying areas of the brain to control aspects of behaviour was developed in the early 1950s such as the lobotomy. These were brutal and imprecise and usually involved severing connections in the frontal lobe to attempt to control aggressive behaviour in patients. Dougherty et al (2002) reported on 44 OCD patients who had undergone a Cingulotomy. At post-surgical follow up after 32 weeks, 1/3 had met the criteria for a successful response to the surgery and 14% for a partial response. This evidence supports localisation of function as it strongly suggests that symptoms and behaviours associated with serious mental disorders are localised. Therefore, it is likely that specific symptoms of serious mental disorders are localised to an extent which helps us to develop more targeted treatments for these disorders.

Question 16

AO3: how is ‘plasticity’ a limitation to localisation of function?

Answer 16

One limitation of localisation of function is that there is research evidence to go against the idea of localisation of function. For example, Lashley (1950) removed areas of the cortex (between 10%-50%) in rats that were learning a maze. No area removed was proven to be more important than any other area in terms of the rats ability to learn the maze. The process of learning appeared to require every part of the cortex rather than being confined to one area. He also described the idea of plasticity, this is when the brain becomes damaged and a particular function has been compromised, the rest of the brain appears to reorganise itself in an attempt to recover the lost function. This evidence suggests we should take a more holistic approach to viewing localisation of function by looking at brain function as a whole rather than looking at individual functions. Therefore, it is likely that learning is too complex to be looked at in a localised way and that learning requires the involvement of the whole brain.
However, Lashley based his research upon the role of rats and their brains. This lacks reliability as the human brain is much more complex and sophisticated than animal brains. Therefore this means its lacks generalisability as we cant generalise the findings of animal behaviour to humans.