localisation of function in the brain

Question 1

what will you talk about in this section?

Answer 1

localisation vs holistic theory

hemispheres of the brain

motor, somatosensory, visual and auditory centres

language centres of the brain

Question 2

localisation vs holistic theory

Answer 2

19th century, Broca + Wernicke discovered specific areas of the brain=particular physical and psychological functions

BEFORE= holistic. All parts involved

Broca + Wernicke ARGUED for localisation of function. diff parts of brain= diff parts of body

injury= areas affected

Question 3

Hemispheres of the brain

Answer 3

cerebrum -> left + right hemispheres
physical + psychological functions controlled by particular hemisphere

LATERALISATION

language=left

Question 4

Motor, somatosensory, visual, auditory centres

Answer 4

cortex= outer layer of hemispheres
four centres (lobes) are
frontal
parietal
occipital
temporal

each lobe= different function

back of frontal= motor area

front of parietal lobe= somatosensory area, sensory info from skin. Amount of SS area devoted to body part determines sensitivity (face + hands=1/2)

occipital lobe at back of brain= visual cortex. info to RVF + LVF, damage to left= blindness in right

Temporal lobes= auditory, speech based.

Question 5

language centres of brain

Answer 5

Brocas area damage= aphasia, speech is slow, lacks fluency.
Brocas most famous patient ‘tan’ because that was the only word he could say. Patients with this have difficulty with prepositions + conjunctions

Wernicke, around the same time and Broca, was describing people with no problem producing language, but difficulty understanding. Speech fluent BUT meaningless.
Wernicke area= left temporal lobe, responsible for language + understanding.

results in Wernicke’s aphasia, nonsense words produced.

Question 6

Give me a strength of localisation of function in the brain

Answer 6

damage 2 areas in the brain linked to mental disorders

Dougherty et al, 44 OCD patients who did neurosurgery involving lesioning of cingulate gyrus , 1/3 successful.

success suggests B associated with serious mental disorders may be localised

Question 7

Give me two weaknesses for localisation of function in the brain

Answer 7

-ve research challenging
Lashley, removed areas of cortex in rats learning route through maze. No area proven to be important in terms of learning ability to remember route. Learning seems to require the whole cortex, rather than confined area.
Suggests higher cognitive processes, learning X localised but more holistic

-ve Dick and Tremblay
2% modern researchers think language in brain is controlled by W and B area.
Advances in technology, fMRI, found language distributed far more holistically
language stream identified across cortex. suggests language organised more holistically, contradicting localisation