localisation of the brain and hempisheric laterisation Flashcards
hemispheres of the brain
- outer layer of both hemispheres is the cerebral cortex
- brain divided into 2 symmetrical halves, called left and right hemisphere
- some of our functions are controlled by a one hemisphere
- thats called laterisation
- left hand side of body controlled by right hem
- right side of body controlled by left hem
what is lateralisation
- when some of our functions are controlled/dominated by one hemisphere
localisation of the function of the brain
- proposed by Broca and wernicke
- diff parts of brain responsible for diff physical and psychological functions
- so if a certain area of the brain is damaged, the area lined with that part of the brain will also be damaged
what is that sometimes Called
cortical specialisation
brocas area
brocas area
function - speech production
location - left frontal lobe
result in damage - brocas aphasia ( slow non fluent speech)
wenickes area
function - understanding language
location - left temporarl lobe
result in damage - wernickes aphasia ( fluent but meaningless speech)
motor cortex
function - voluntary movement
location- back of the frontal lobe
result in damage - difficulty with voluntary movement
somatosensory cortex
function - sensory information processing
location - front of parietal lobes ( central sulcus)
result in damage - los of sensation or control of fine movements
visual cortex
function- processes visual information
location - occipital lobe
result in damage- blindness in corresponding visual field
auditory cortex
function - analyses speech based sound information
location - temporal lobe
result in damage - hearing loss
ao3 strength
para 1
p- research to support localisation of brain function
e- Peterson et al , found wernickes area was active during listening tasks, whereas Broca area was active during reading tasks
e- additionally, tulving found that diff types of memory are stored in diff parts of brain
l- suggest that brain areas have diff functions that are specific to that area, supporting theory of localisation of brain function
ao3 neg
p- evidence that contradicts localisation theory for brain functions
e- the work of lashley suggests higher cognitive functions isn’t localised but distributed in more holistic ways ( evenly across entire brain)
e- lashley removed areas of cortex in rats that were learning a maze, no area was proven to be anymore important in learning the maze, learning then appeared to require every part of the cortex rather than being confined to one specific area
l- suggests that learning may be too complex to be localised , and requires whole brain, contradicting brocas and wernickes theory
ao3 support
para 2
p- support from case studies
e- case of Phineas gage ,railroad explosion forced meter long metal pole through left cheek, exited his skull from top of his brain taking most of his frontal lobe with it
e- gage survived but damage to brain left mark on personality, changed from someone calm and reserved - quick tempered and rude
l- suggests that personality and mood regulation may be localised to frontal lobe, supporting lobf their
ao3 disadvantage
para 2 for dis
p- alternative theories that contradict
e- theory of platisicity , says that when brain becomes damaged from illness or accident, and particular function has been lost other areas of the brain are able to compensate for the damaged region to recover lost function
e - several cases of stroke patients being able to recover lost abilities to back up theory eg Jodi miller
l- raises possibility that there may be more accurate alternatives to lobf theory
