Brain Plasticity Flashcards
Outline what is meant by brain plasticity
Brain has ability to change throughout life, enabled by synaptic pruning - new neural connections formed in response new demands in brain
During infancy, brain experiences rapid growth in number of synaptic connections - peaking at 15,000 per neuron at 2-3 yo (2x more than adult brain)
Synaptic pruning = as we age, rarely-used connections deleted & frequently-used connections strengthened
Outline research into plasticity
Maguire (2000) studied brains of London taxi drivers & found significantly more volume of grey matter in posterior hippocampus than matched control group - part of brain linked with spatial & navigational skills
They must pass ‘The Knowledge’ - complex test assessing recall of city streets & routes
This alters structure of their brains
Longer drivers had been in job, more pronounced structural difference
Outline functional recovery after brain trauma
Following trauma, e.g. physical injury, unaffected areas of brain adapt & compensate for damaged areas - example of neural plasticity
Taking over from functions from damaged areas
Process can occur quickly after trauma, (spontaneous recovery) then slow down after several weeks/months
At this point, person may require rehab therapy to further recovery
Outline what happens in the brain during recovery
Brain able to rewire & reorganise itself by forming new synaptic connections close to damaged area
Secondary neural pathways wouldn’t typically be used to carry out certain functions are activated to enable functioning to continue, often in same way as before
Supported by AS, DS, RH
Evaluate brain plasticity
Strength - AGE & PLASTICITY - Brain plasticity = life-long ability
E.g. - In general, plasticity reduces with age, but Bezzola et al. (2012) - 40 hours of golf training produced changes in neural representations of movement in parties aged 40-60. Using fMRI, researchers saw increased motor cortex activity in novice golfers compared to control group - more efficient neural representations after training
Ex. - Neural plasticity can continue throughout lifespan
Limitation - NEGATIVE PLASTICITY - Negative behavioural consequences
E.g. - 60-80% of amputees develop phantom limb syndrome: continued xp of sensations in missing limb as if it’s still there. They’re usually unpleasant, painful & due to cortical reorganisation in somatosensory cortex as result of limb loss
Ex. - Brain’s ability to adapt to damage isn’t always beneficial
Evaluate functional recovery after brain trauma
Strength - REAL WORLD APPLICATION
E.g. - Contributed to neurorehabilitation as knowing axonal growth is possible encourages new therapies to be tried, e.g. constraint-induced movement therapy: stroke patients repeatedly practise using affected part of body while unaffected side restrained
Ex. - Research into functional recovery = useful as it helps medical professionals know when interventions need to be made
Limitation - COGNITIVE RESERVE - Education level may influence recovery rate
E.g. - Schneider et al. (2014) revealed more time people with brain injury spent in education (indication of their ‘cognitive reserve’) greater chances of disability-free recovery. 40% of those having DFR had >16 years ed compared to those <12
Ex. - Implies people with brain damage who’ve insufficient CR less likely to achieve full recovery
Outline the structural processes supporting the process of brain recovery
Axonal Sprouting - Growth of new nerve endings connect with other undamaged nerve cells to form new neural pathways
Denervation Supersensitivity - When axons doing similar job aroused to higher level to compensate for lost ones. Negative consequence = oversensitivity to pain
Recruitment of Homologous (same) Areas on opposite sides of brain - specific tasks can still be performed
