neuroplasticity and functional recovery Flashcards
what did scientists used to believe about the brain?
that it was ‘static’, however this was revised and it is not believed that the brain is ‘plastic’
what is neural plasticity?
the apparent ability of the brain to change and adapt its structures and processes as a result of experience and new learning
how many synaptic connections does an infant aged 2-3 have?
15,000
how many synaptic connections does an adult have?
7,500-8,000
what is synaptic pruning?
when rarely used connections are deleted and frequently used connections are strengthened
what do we develop in our first few years of life?
our brains are adaptable and we develop schemas
Maguire- ‘London taxi driver study’
•aimed to investigate neural plasticity and the extent to which the brain can grow/ change
•she studied the brains of london taxi drivers and found significantly more volume of grey matter in the posterior hippocampus (responsible for spatial awareness) than in a matched control group
•it was a natural study
•she scanned the brains before learning, during and after ‘the knowledge’ test.
•she found that the size of the posterior hippocampus increased, and the structural difference was more pronounced the longer they had been in the job (positive correlation)?
•found evidence of neural plasticity
functional recovery of the brain after trauma
•healthy brain areas may take over those areas that are damaged
•this process can occur quickly but slows down after time
•secondary neural pathways that would not usually be used to carry out certain functions are activated to enable functioning to continue
•this process is supported by a number of structural changes
what are the structural changes that occur in the brain during recovery?
-axonal sprouting: the growth of new nerve endings which connect with other undismayed nerve cells to form new neuronal pathways
-reformation of blood vessels
-recruitment of similar areas on the opposite side of the brain to perform specific tasks. an example would be if broca’s area was damaged on the left side of the brain, the right sided equivalent would carry out its functions. after a period of time, functionality may then shift back
case study- Gabby Giffords
•former US politician who survived an assassination attempt when she was shot in the head from point blank range
•she made staggering progress after the bullet was shot through the left side of her brain
•she regained total control over the left side of her body. she could read, understand and speak in short phrases
•she is an example of the brains ability to heal itself from a serious trauma
maguire limitation: unrepresentative sample
•gender (men) and culture bias (londoners, used to reading maps)
•the sample likely had a genetic predisposition for their posterior hippocampus to grow and understand spatial positions.
•they could have had a predisposition to develop spatial awareness
strength: practical application, neurorehabilitation
•spontaneous recovery tends to slow down after a few weeks, so different forms of therapy may be needed to continue showing improvements
•it may require movement therapy or electrical stimulation
•the brain can ‘fix itself’ up to a point, after which intervention is needed
•an understanding of neural plasticity helps devise therapies
limitation: the concept of cognitive reserve
•evidence suggests that a persons educational attainment may influence how well the brain functionally adapts after an injury
•schneider discovered that the more time brain injury patients had spent in education- which was an indication of their ‘cognitive reserve’- the greater their chances of a disability free recovery
•positive correlation between the amount of time in education and the amount of people who achieved a disability free recovery
limitation: depends on your access to healthcare
•your recovery may be hindered by your wealth and social status, as the more money you have means you have access to higher quality healthcare and surgeons
•Gabby Giffords’ case may not be totally generalisable as she had access to the best health care possible
