plasticity and functional recovery Flashcards
(10 cards)
what is brain plasticity
during infancy the number of synaptic connections grows to its maximum (15 000)
this is about twice as many as an adult brain
as we progress barely used connections are deleted and frequently used connections re strengthened- synaptic pruning
this process enables lifelong plasticity where new connections are formed when new information is learned
research into brain plasticity
maguire- taxi study
found significantly more volume oif grey matter in the posterior hippocampus than in a matched control group
this part of the brain is associated with spatial and navigational skills
as part of their trainibg they have to complete a test called the knowledge
positive correlation between the longer the taxi driver had been in the job the more pronounced the structural difference
what is functional recovery
following a brain injury or trauma eg a stroke areas of the brain are often able to adapt and replace the functioning of the damaged part
axonal sprouting
the growth of new never endings which connect with existing ones to create new neuronal pathways replacing damaged ones
denervation supersensitivity
when axons with a different function become aroused to a higher level of functioning to compensate for damaged and lost ones
however a negatuve consequence of this is that oversensitivity to sensations like pain can be experienced
recruitment of homologus areas on the other hemisphere
eg if brocas area was damaged a right hemisphere equivalent would be used
limitations of plasticity
- negative behavioural consequences
phantom limb syndrome, can be painful and unpleasent
occurs in 60-80% of amputees due to cortical reorganisation in the somatosensory cortex
the brains adaption to prolonged drug use has also been linked to dementia and a decline of cognitive functioning in later life
strengths of plasticity
+ there is evidence to suggest that plasticity may be a life long ability
plasticity reduces with age however bezzola found that 40hrs of golf changed neural representations of movement in brains of people aged 40-60 years
fMRI scan revealed reduced activity in motor cortex compared to a control group suggesting more efficient neural representations after training.
limitations of functional recovery
- schnider found a positive correlation between length of time spent in education and chance of a disability free recovery
- people with over 16 years in education had a 40% chance of DFR
- people with under 12 years in education had a 10% chance of DFR
people with an insufficient cognitive reserve are unable to acheive full recovery
strengths of functional recovery
+ real world application, advances in neurorehabilitation, constraint induced therapy is used on stroke patients, moving affe ted arm constantly while restraining unaffacted arm.
