BIOPSYCHOLOGY 2.0 Flashcards
what is the holistic theory of brain function?
any partof brain could carry out any function
when was the holistic theory of brain function challenegd?
when it was found that ppl who suffered trauma in pat part of brain
-> thru illness or accidents lost spec function
what are the early studies? (3)
case of phineas gage
work of broca and wernicke
on role of brain in speech + lang
who was phinea gage? waht was he known for?
1823-1860
american railroad construction foreman
being the victim of an accident in 1848 that greatly contributed
to our understanding of cognitive neuroscience
and localisation of brain function
waht was the cause of the acc+ the subsequent injury he received?
tamping iron went through his frontal lobe
… damaging it
when he was compacting gun powder
-> that was when the gun powder ignited
after the accident what skills did gage retain?
could still walk + talk
brain could still regulate
desc gage p before accident
smart
energetic
determined
thoughtful
after acc?
rude and vulgar
what can we concl about br func from case of phineas gage?
brain made of diff parts
each w diff funct
-> frontal lobe controls the personality
who was Paul Broca?
1824- 1880
french surgeon + studied in uni of paris
when did Broca discover brocas area?
when Tan died at 51 (1860s)
where is Brocas area located?
in frontal lobe in left hemisphere of brain
how did Broca make his discovery
Tan suffered w epilepsy + lsot ability to speak at 30
10yrs later he met Tan in surgery 1861
broca found tans underst of speech seemed rel in tact
broca was curious about y this should be
-> tan died 51 Broca perf post mortem
.. found damage in brocas area
what is the role of brocas area?
controls speech
-> ability to prod meaningful sounds
allows us to haev good control over tongue/mouth muslces
in order to prod speech
what happens if brocas area damaged?
could lose ability to prod meaningful sounds
.. affect ability to communicate
however inteliigence + lang comprehension still remains in tact
.. can still underst language
difficulty rpoducing connective “and”
waht is it called if brocas area is damaged?
Broca aphasia
who is carl wernicke?
1848 - 1905
german physician
known fro disc wernickes area shortly after broca 1874
wehre is wernickes area located?
in dominant cerebral hemisphere
-> left hemisphere and further back in temporal lobe
how did wernicke make his disc?
w noticed not all lang deficits were resutl of damaged to brocas area
obs patients w brain damage as result of stroke
-> noted all beh + conducted post mortem autopsies to locate brain damage
what is the role of wernickes area?
controls comprehension of language
what happens if wernickes area is damaged?
results in receptive or fluent aphasia (wernicke aphasia)
.. unable to understand lang in neither written or spoken form
-> but speaks w normal grammar, syntax, innotation
however cannot express themselves meaningfully using language
what do all of these early studes give rise to ?
gives rise to theory of localisation of brain function
.. each part of brain carries out a pat func
desc str of brain
divided into 2 hemispheres
left and right
-> connected by thin band of tissue called the corpus collosum
desc func of brain?
for most funct 2 hemispheres are symmetrical
altho some processes controlled by 1 side of br only
-> most of body ocntrolled by opp hemisphere of br
e.g picking up smth w right hand would be controlled by left hemsphere
-> this is called lateralisation
waht is the outermost layer of the brain called?
cerebral cortex
is highly folded + much more dev in humans than in other mammals
.. allows huamans to ahve a much higehr cog function
-> eg h can appreciate and eval artworks
-> eg cant do further planning of future
but animals cant
-> due to having a larger cerebral cortex
how is cerebral cortex divided?
cerebral cortex in both left and right hemispher divided into lobes
-> each lobe is subdivided into areas that control diff functions
motor cortex descp
in each hemisphere area controls the voluntary muscle movements in opp sides of body
if area damaged muscles may be paralysed + fine motor control can be lost
-> eg writing, using a knife etc
this cortex is at back of frontal lobe
brocas area descr
located in frontal lobe
most ppl its found only in left hemisphere
auditory cortex descr?
damage to this cortex may produce hearing loss or reduce ability to understand lang
areais found in each hemisphere in temporal lobe
somatosensory cortex descr?
front of the parietal lobes
recieves sensory info
from receptors in skin about temp, pressure etc
skin areas of high sens e.g face are represented by larger areas within this cortex
visual cortex descr?
area processes info from eyes
crotex is in the occipital lobe
each eye send sends info from right visual field to the part of the cortex in left hemisphere
.. damage to only 1 half of occipital lobe can affect vision in both eyes
wernickes area descr?
in temporal lobe
most ppl found in left hemisphere only
support for theory of localisation of brain function
-> supprots brain ahs diff parts to do diff functions (3)
work of broca supports idea of pat brain areas performing sepc functions
.. sugg brocas area controlls production of speech
work of wernicke supprots -> wernickes area
-> damage to w area caused fluent aphasia
both studies highly scientific -> post mortems .. empirical evidence
brain scans have shown lang proesses are localised in brain - Petersen 1988
-> conducted br scans showed w area active when lsitening to lang being spoken + brocas area active whilst reading aloud
Dougherty 2002 reported on 44 OCD patients who ahd undergone cingulotomy.
at psot surgical follow up after 32 weeks
a third of p met criteria for succ resp to surgery
14% of p were partial resp to srgery
-> shows symptoms or beh assoc w serios mental disorders are localised
whats cingulotomy
neurological proc
involved isolating part of the brain
which thought to be involved w OCD
contradiction to localisation o brain function? (2)
the brain can show plasticity
-> Draganski et all 2006
imaged the brains of med students 3 months b4 + after final exams
-> learning induced changes have occured to posterior hippocampus and parietal cprtex
as a reuslt of exam
… shows brain can adapt and change in resp to certain experiences
… shows 1 part on brain does not have only 1 specific function
some brain function may be holistic rather than localised
lashley 1950 studied learning in rats by removing 10-50% of their cerebral cortex that were learning a maze
rats ability to learn was not affected by removal of any pat part of brain
.. supports the fact that learning maze req every part of brain
-> learning is not a localised function
what is another phrase for plasticity?
cortical remapping
what does plasticity mean?
refers to the brains ability to change + adapt in resp to exp and learning
when did plasticity used to be thought it ocuured?
plasticity thought to be occured only in childhood
- > has been known for a long time that brain incr no of synaptic connections
- > peaks around 3 yr old
- > as we get older connections we use freq stregnthen and those we dont get lost
- > this is called synaptic pruning
waht else about plasticity?
used to be thought inadolesence critical period
once passed brain showed no furhter plasticity
-> recent studies showed that plasticity can occur in adulthood
-> examples are Maguire et all 2000
what was procedure of maguire et al 2000?
16 healthy right handed male licenesd London taxi drivers participants have to pass test of knowlegde
-> mean age 44
taxi drivers brain scans compared with scans of 50 healthy right handed males who did not drive taxis
the r used MRI scans + controlled v
->e.g no. of years of taxi dr, age, sex and handedness
data collected using MRI
MRI scanner exposes a p’s br to a strong mag field + radio waves
.. producing detailed pics of brain
+ used VBM to measure density of grey matter in brain
findings of maguire et al 2000?
posterior hippocampus of taxi drivers sig larger relative to those of control subj
anterior hippocampal region was larger in control subj than in taxi drivers
second main findings was hippocamal vol correlated with amount of taxi driving years
-> positively in the right posterior and neg in the right anterior hippocampus
-> the VBM analysis found taht sign incr grey matter vol was found in brains of taxi dr
compared w thoes of controls in only 2 brain regions, namely the right and the left hippocampi
no diff were observed elsewhere in brain
concl?
maguire et al argue that this study demonstrates that plasticity of hippocampus in resp to environmental demands
they argue that posterior hippocampus stores a spatialrepresentation of the envi + in london taxi drivers the vol of posterior hippocampus expanded bc of their dependance on navigation skills
pos of maguire? (3)
normally diff to make concl from natural/quasi exp as any diff found between 2 grps (e.g vol of grey matter) may not have occured bc of IV -> if they r taxi driver
however r carried out orrelational analysis which clearly demonstr theres a strong pos correlation betwe legnth of time p driving taxis + their posterior hippocalpul vol
.. sugg legnth of time driving taxi in london assoc w grey matter within hippocampus
MRI scans highly scientifiv + empirical methods of inv providied vast amount of quantitive data
-> relating to vol + size of hipoocampus
.. enabling them to carry out statistical analysis + make direct comparisons
-> employed many controls, eg samples amtched for age, sex and handedness
also r analysing brain scans were “blind”
-> they did not kno if brain scan belonged to a taxi driver or non taxi driver
.. incr the internal validity of results
.. can be more confident when drawing conlc
neg of maguire et al 2000
all p were male .. not a repr sample -> may be differences betw males+ females in terms of spatial memory ... resukts diff to gen onto women -> .. lacks population validity
name 2 other r into plasticity?
mechelli 2004 -> bilingual ppl had a larger parietal cortex comp to matched participants who had spoken one lang
draganski et al 2006
waht is functional recovery?
is the typeof plasticity shown after brain damage or trauma
in many casesbrain can rtansfer functions from damaged parts to undamaged parts of the brain so function can be recovered
it may be that the function is transferred to the homologous area (same area) in the other hemisphere
thought that functional recovery occurs quickest after trauma is expierienced + slows down later
.. rehabilitive theraphy most effective if used straigth after trauma if patient can
-> in order to assist functional recovery
