plasticity and functional recovery of the brain after trauma- biopsychology

Question 1

what is brain plasticity

Answer 1

brain appear to be plastic sense that it has ability to change throughout life
infancy- brain experiences rapid growth in number of synaotic connections peaking 15k per neuron at 2-3 years- twice as many as there are in the adult brain
as age rarely used connections deleted and frequently used connections strengthrned- process known as synaptic pruning
synaptuc pruning enables lifelong plasticity where new neural connections formed in response new demands on brain

Question 2

what is the research into plasticity

Answer 2

maguire-studied brains of london taxi drivers found sigf more volume og grey matter iin posterior hippocampus than in matched control group
part of brain associated with development of spatial and navigational skills in humans and other animals
london cabbies must take complex test called the knowledge assesses recall of city streets and possible routes
found longer taxi drivers been in job more pronounced was the structural difference -positive correlation
similar findings observed by draganski who imaged brains of medical students three months before and aftr final exams
learning induced changes were seen to have occured in the posterior hippocampus and the parietal cortex presumably asresult of learning

Question 3

what is after brain trauma

Answer 3

following physical injury or other forms of trauma unaffected areas of brain are often able to adapt and compensate for thoseareas that are damaged
functional recovery may occur in brain after trauma an example of neural plasticity
healthy brain areas take over functions of those areas that are damaged destroyed or even missing
neuroscientists suggest this process can occur quickly after trauma and then slow down after several weeks or months
individual may require rehabilitative therapy to further recovery

Question 4

what happens in the brain during recovery

Answer 4

able to rewire and reorganise itself forming new synaptic connections close to area of damage
secondary neural pathways would not typically be used to carry out certain functions activated or unmasked to enable functioning to continue same way as before
process supported by number structural changes in brain
axonal sprouting- growth of new nerve endings which connect with other undamaged nerve cells form new neuronal pathways
denervation supersensitivity- occurs when axons do similar job become aroused to higher level compensate for ones that are lost, can have negative conseuqence of oversensitivity to messages such as pain
recruitment of homologus areas on opposite side of brain, means specific tasks can still be performed- if broxas area damaged on left side of brain the ride sided equivalent would carry out functions, after period of time functionality may shift to left side

Question 5

what is negative plasticity

Answer 5

weakness- may have negative behavioural conseuquences
evidence shown brain adaptation to prolonged drug use leads to poorer cognitive functioning in later life as well as increased risk of dimentia
60-80% amputees have been known to develop phantom limb syndrome- continued experience of sensations in missing limb as if it were still there, sensations usually unpleasant painful and are thought to be due to cortical reorganisation in somatosensory cortex that occurs as result of limb loss
suggests brain ability to adpat to damage not always beneficial

Question 6

what is age and plasticity

Answer 6

strength- brain plasticity may be life long ability
general plasticity reduces with age
bezzola demonstrated how 40hrs of golf training produced changees in neural representations of movement in pps ages 40-60, using fmri researchers observed increased motor cortex activity in the novice golfers comapred to control group suggesting more efficient neural representations after training
shows neural plasticity can continue throughout lifespan

Question 7

what is seasonal brain changes

Answer 7

suggests there may be seasonal plasticity in brain in response to environmental changes, suprachiasmatic nucleus which regulates sleep/wake cycle evidence that particular brain structure shrinks in all animals during spring and expands thrugh autumn

much of work on seasonal plasticity has been done on animals, notablu songbirds
human behaviour may be controlled different

Question 8

what is real world application

Answer 8

strength- functional recovery real world applicaiton
understanding processes involved in plasticity contributed to field of neurorehabilitation
understanding axonal growth possible encourages new therapies tried
constraint induced movement therapy used with stroke patients repreatedly practice using affected part of body which unaffected arm is restrained
shows research functional recovery useful as it helps medical professionals know when interventions need to made

Question 9

what is cognitive reserve

Answer 9

weakness- functional recovery level of education may influence revoery rates
schnieder revealed that the more time people with brain injury had spent in education take as indication of cognitive reserve the greater their chances of disability free recovery
40% of those who achieved dfr had more than 16 years education comapred to 10% of those who had less than 12 years education
imply that people with brain damage who have insufficient dfr less likely to achieve full recovery

Question 10

what is small samples

Answer 10

research ongoing new treatments to aid functional recovery
banerjee treated people who had total anterior circulation stroke with stem cells, all pps trial recovered compared to more typical level of just 4% recovery

study drew conclusions based on 5 pps and no control group which fairly typical of research on functional recovery