localisation of function in the brain

Question 1

what is localisation of function?

Answer 1

The theory that different areas of the brain are responsible for specific behaviours, processes or activities.

Question 2

what is the motor area?

Answer 2

A region of the frontal lobe involved in regulating movement.

Question 3

what is the somatosensory area?

Answer 3

An area of the parietal lobe that processes sensory information such as touch.

Question 4

what is the visual area?

Answer 4

A part of the occipital lobe that receives and processes visual information.

Question 5

what is the auditory area?

Answer 5

Located in the temporal lobe and concerned with the analysis of speech-based information.

Question 6

what is Broca’s area?

Answer 6

An area of the frontal lobe in the left hemisphere (in most people), responsible for speech production.

Question 7

what is Wernicke’s area?

Answer 7

An area of the temporal lobe (encircling the auditory cortex) in the left hemisphere (in most people), responsible for language comprehension.

Question 8

localisation vs holistic theory?

Answer 8

before Broca & Wernicke argues for localisation of function scientists generally supported the holistic theory of the brain.

Question 9

what are the hemispheres of the brain?

Answer 9

The main part of the brain (the cerebrum) is divided into two symmetrical halves called the left and right hemisphere.
Lateralisation: some psychical & psychological functions dominated by 1 hemisphere.
Left-side controls the right side of the body & vis versa.
Language linked to left

Question 10

what are the 4 centres?

Answer 10

The cortex of both hemispheres is subdivided into four centres - called the
‘lobes’ of the brain: the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe. A ‘lobe’ is a part of an organ that is separate in some way from the rest. Each lobe in the brain is associated with different functions.

Question 11

what does the motor area do?

Answer 11

at the back of the frontal lobe, controls voluntary movement in the opposite side of the body. Damage to this area of the brain may result in a loss of control over fine movements.

Question 12

what does the somatosensory area do?

Answer 12

front of both parietal lobes, separated from the motor area by a ‘valley’ - central sulcus.
where sensory information from the skin is represented. The amount of somatosensory area devoted to a particular body part denotes its sensitivity.

Question 13

what does the visual area do?

Answer 13

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 right visual cortex. This means that damage to the left hemisphere, for example, can produce blindness in part of the right visual field of both eyes.

Question 14

what does the auditory area do?

Answer 14

in the temporal lobe.
analyses speech-based information. Damage may produce partial hearing loss. The more extensive the damage, the more extensive the loss. In addition, damage to a specific area of the temporal lobe Wernicke’s area may affect the ability to comprehend language.

Question 15

what are the language centres?

Answer 15

Broca identified a small area in the left frontal lobe responsible for speech production. Damage to Broca’s area causes Broca’s aphasia which is characterised by speech that is slow, laborious and lacking in fluency.

Wernicke identified a region in the left temporal lobe as being responsible for language understanding. This results in Wernicke’s aphasia when damaged. People who have Wernicke’s aphasia will often produce nonsense words as part of the content of their speech.

Question 16

what is the evidence from neurosurgery strength?

Answer 16

-damage to areas of the brain has been linked to mental disorders.
-Neurosurgery is a last resort method for treating some mental disorders, targeting specific areas of the brain which may be involved.
-For example, cingulotomy involves isolating a region called the cingulate gyrus which has been implicated in OCD.
Darin Dougherty et al. (2002) reported on 44 ppl w OCD who had a cingulotory.
-At post-surgical follow-up after 32 weeks, about 30% had met the criteria for successful response to the surgery and 14% for partial response.
The success of these procedures suggests that behaviours associated with serious mental disorders may be localised.

Question 17

what is the evidence from brain scans strength?

Answer 17

-supports the idea that many everyday brain functions are localised.
-For instance, Steven Petersen et al. (1988) used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task.
-this study confirms localised areas for everyday behaviours.
-Therefore objective methods for measuring brain activity have provided sound scientific evidence that many brain functions are localised

Question 18

what is the counterpoint for evidence from brain scans?

Answer 18

-A challenge to localisation theory comes from the work of Karl Lashley (1950). -Lashley removed areas of the cortex (between 10% and 50%) in rats that were learning the route through a maze.
-No area was proven to be more important than any other area in terms of the rats’ ability to learn the route. The process of learning seemed to require every part of the cortex rather than being confined to a particular area.
-This suggests that higher cognitive processes, such as learning, are not localised but distributed in a more holistic way in the brain.

Question 19

what is the language localisation questioned limitation?

Answer 19

-language may not be localised just to Broca’s and Wernicke’s areas.
-A recent review by Anthony Dick and Pascale Tremblay (2016) found that only 2% of modern researchers think that language in the brain is completely controlled by Broca’s and Wernicke’s areas.
-Advances in brain imaging techniques, such as fMRI, mean that neural processes in the brain can be studied with more clarity than ever before.
-This suggests that, rather than being confined to a couple of key areas, language may be organised more holistically in the brain, which contradicts localisation theory.

Question 20

what is the case study evidence strength?

Answer 20

• there is case study support.
  -Unique cases of neurological damage support localisation theory, such as the case of Phineas Gage.
  -However, there are problems with case studies. It is difficult to make meaningful generalisations from the findings of a single individual.
  -Also, conclusions drawn may depend on the subjective interpretation of the researcher.