plasticity/functional recovery Flashcards
what is plasticity
the brains ability to change and adapt as a result of experience and new learning
what’re properties of the brain
•always changing on molecular levels via the creation of neurons as you learn things
•brain plasticity
• synaptic pruning after neurons become irrelevant
what does age have to do with neurons in the brain
•’growth spurt’ of the creation of thousands of synaptic connections with peak neuron quantity at ~3 years old (infancy)
• ‘synaptic pruning’ where some connections that are rarely used are ‘cut’ (young child)
• the brain can still learn/adapt throughout adulthood due to the adaptation, change and growth of new synaptic connections (plasticity still occurs)
what is functional recovery
a form of plasticity, the brain has the ability to redistribute/transfer functions usually performed by a damaged area to other in damaged areas
what was maguire’s research into plasticity
studied the brains of london taxi drivers with MRI brain scans ti investigate brain plasticity effects. used matched control groups
what is the posterior hippocampus associated with
spacial navigation
what’re findings from maguire’s study
found a positive correlation between the duration that people had been london taxi drivers and how pronounced the structural difference of the posterior hippocampus was
what is a support of maguire’s study
very scientific, uses control of non-taxi drivers as a comparison and uses objective measure of MRI scans, good internal validity
what is a weakness of maguire’s study
only shows correlation, werent tested before the ‘knowledge test’ needed for the job, cannot establish before-and-after cause-and-effect, the uptake of memory needed isn’t directly proven to cause the posterior hippocampus to be more pronounced, weakening the internal validity
what’re 2 later examples that support maguire’s findings
•med students brains were imaged 3 months before their medical exams, learning induced changes (larger/more connections) were found in posterior hippocampus and parietal cortex
• bi-linguals had a lather parietal cortex than mono-lingual matched controls
how does the case study of jody support functional recovery/plasticity
after losing her whole RH in a hemispherectomy at aged 3 due to extreme epileptic seizures, she now lives a normal life (RH filled with spinal fluid)
what happens during brain recovery
(Never Scare A Drunk Rhino)
•New synaptic connections close to damaged area
•Secondary neural pathways ‘unmasked’ or activated
•Axonal sprouting, growing new nerve endings to form new neural paths
•Denervation Super Sensitivity, axons that do a similar job (to damaged) are aroused to a higher level to compensate
•Recruitment of Homologous Areas, similar areas on the opposite hemisphere are recruited to perform tasks e.g. broca’s move to the RH
what’re 4 positive evaluations of functional recovery
Practical application, Plasticity with age, Occipital lobe plasticity, and ‘cognitive reserve’
what’s 1 negative evaluation of functional recovery
not all plasticity is good as there may be negative consequences, for example 60-80% of amputees suffer from ‘phantom limb syndrome’ and is often painful/unpleasant. this is thought to be due to cortical reorganisation in the somatosensory area that occurs as a result of limb loss. Therefore this negatively represents the benefits of plasticity via functional recovery
how is practical application a strength for functional recovery
neurorehabilitation has been developed, including physical and movement therapy may help the brain ‘fix itself’. for example, ‘constraint induced movement therapy’ is used on stroke patients, making patients repeatedly use the affected part of the body eg lifting an arm whilst the unaffected arm is restrained. this allows for greater recovery of stroke patients due to greater understanding of how the brain recovers via functional recovery
how is age a practical evaluation for functional recovery
evidence shows plasticity occurs at all ages, eg bezzola gave people aged 40-60 who had never played golf 40 hours of training and scanned their brains with fMRI scans before/after the training. they found increased motor cortex activity in the novice golfers, as their motor area became more efficient or ‘streamlined’ after practice, suggesting that neural plasticity occurs all throughout life.
how is the occipital lobe positive evaluation for functional recovery
Hubel and Wiesel sewed the eye of a kitten shut, and instead of remaining idle the visual cortex associated with the shut eye started processing info from the other eye. this shows, at least in animals. that inactive brain areas can change/adapt to take in new functions after damaged supporting the processes of functional recovery
how does ‘cognitive reserve’ positively support functional recovery
the better the cognitive reserve the better the recovery from brain injury. 40% of fully recovered patients had >16 years in education, with 10% of the fully recovered patients having just 12 years in education. By spending more time in education the human brain is more adapted to taking in information via the greater availability of neurons, helping functional recovery occur, showing how factors such as education may impact successful recovery, and hints at other factors such as gender or health having impacts on the likelihood of functional recovery
