LOCALISATION OF FUNCTION IN THE BRAIN AND HEMISPHERIC LATERALISATION Flashcards
what was believed pre 19th century?
took a holistic approach saying that all parts of the brain were involved in processing thoughts and actions
what 2 psychologists are important in localisation of func?
Wernicke
Broca
what did Broca and Wernicke say?
specific parts of the brain are involved in specific psychological/physiological function
what can localisation of function also be referred to as?
cortical specialisation
wernicke and broca said if a certain area of the brain is damaged then…
the brain wouldn’t perform function
where is wernicke’s area?
left temporal lobe
what is wernicke’s area associated with?
language processing and comprehending information
can people with wernicke’s aphasia understand what someone is saying?
no
can people with wernicke’s aphasia respond?
yes but it is meaningless
where is broca’ s area?
left frontal lobe
what case study do you refer to in broca’s area?
LeBorgne, also known as Tan
explain the case study of Tan
understood spoken language, but couldn’t produce coherent words, could respond with left hand e.g. thumbs up/down
what is broca’s area associated with?
speech production
what does broca’s aphasia lead to?
slow, inarticulate and incomplete speech
what is the frontal lobe responsible for?
the motor area
what does the frontal lobe control?
voluntary movement in opposite side
what does damage to the frontal lobe do?
it means loss over fine movements e.g. facial movements, speech control etc.
what is the parietal lobe responsible for?
somatosensory area
what is the parietal lobe and frontal lobe separated by?
central sulcus channel
parietal lobe get ____ info from ____…
sensory information from skin e.g. pressure, touch and heat
what does the amount of area in parietal lobe amount to?
it amounts to the amount of receptors e.g. face takes up half of parietal lobe
what is the occipital lobe responsible for?
visual area
where is the occipital lobe located?
at the back of the brain visual cortex
if there is damage to the left hemisphere’s occipital lobe, what can be affected?
damage to BOTH eyes right visual fields
what is the temporal lobe responsible for?
auditory info
what does the temporal lobe do?
analyse speech based info
what can damage to the temporal lobe lead to?
produce partial hearing loss
what are 4 evaluation points for localisation of function?
+ evidence from neurosurgery
+ brains scans support localisations
- language can be localised in other places
- phineas gage is not applicable
there is evidence from _______ to support localisation
neurosurgery
who found research for evidence for neurosurgery?
dougherty et al
what did dougherty et al study?
44 ppl w/ OCD after cingulotomy, which had links to implications for OCD
what did dougherty et al find?
at 32 weeks - 30% had a successful response and 44% had a partial responsed
evidence from neurosurgery increases…
the credibility of the localisation of function, as it shows that different areas of the brain have different functions
increases practical application as it has increased theoretical value for treatment
there is evidence from _____ ______ to support localisation
brains scans
what do brain scans confirm?
localised area for everyday behaviour
who studied brain scans?
Petersen et al
what did Petersen et al find?
brain scans for wernicke’s area showed it was active during listening and for broca’s area showed it was active for reading
brains scans increase the…
validity of the explanation because it is objective brain scan supporting localisation
who criticises brain scan evidence?
Lashley
how does Lashley criticise brain scan evid?
found that function was holistic in rats, removed 10-50% of frontal cortex, which didn’t affect learning
a weakness of localisation is that ______ can be localised in other places
language
it was found that by Dick and Tremblay that language is…
distributed more holistically
who found that language can be distributed more holistically?`
Dick and Tremblay
what did Dick and Tremblay find?
2% researcher agree with lang being in Wernicke’s and Broca’s area
what did Dick and Tremblay find in fMRI scans?
language streams identified across the cortex, in right hemph and substructures such as the thalamus
what does Dick and Tremblay’s research reduce?
reduces the validity of the exp as main studies may need to be repeated to see whether language is distributed more holistically throughout the brain
a weakness of localisation of func is that case studies….
such as Phineas Gage are too unique
Phineas Gage’s case being too unique reduces the…
generalisability of the theory
why does Phineas Gage’s study not allow generaliability?
because the conclusion of his accident depends on the researcher, some people can say he changed because of his brain, whereas other can say it is due to trauma of the accident
Case studies lower the…
population validity because most people will never go through something like that in their lifetime, and conclusions from the case are very subjective
define localisation
different areas of the brain responsible for specific behaviours, processes or activities
define lateralisation
different hemispheres responsible for different functions independently
examples of lateralisation can be…
language in left hemph
left visual field in right hemph vice versa
left hand movement in right hemph vice versa
what can the corpus callosum be known as?
headquarters of the hempishere
what is the corpus callosum?
made up of nerve fibres, known as commissural fibres attached to both hemispheres
what happens in the corpus callosum?
electrical impulses travel to hemisphere
what is split brain procedure?
surgeons contain seizure ( overload of imp) to one hemisphere to reduce damage, cut corpus callosum, only last resort if medication doesn’t work
