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plasticity and functional recovery of brain after trauma - Coggle Diagram
plasticity and functional recovery of brain after trauma
plasticity
describes the brains tendency to change and adapt as a result of experience and new learning
Maguire et al 2002
aim - to examine whether structural changes could be detected in the brain of extensive experience of spatial navigation
procedure - male taxi drivers in London doing the knowledge test - used structural MRIs to see their posterior hippocampus and compared the results with a control group
findings - taxi drivers had more grey matter, the longer they had been in the job, the more pronounced was the structural difference
conclusion - this is an example of plasticity in the brain as structural changes were found
Kuhn et al 2002
aim - looking at plasticity through gaming
procedure - video game group play Mario kart for 30 mins a day for two months and the results are compared results with a control group - checked g=changes through MRI scans.
findings - the video game group had an increase in grey matter in areas of the brain that controlled spatial awareness, strategic thinking etc, the control group didn't show an increase
conclusion - this is an example of plasticity in the brain
meditation
has shown to produce changes in brain structure
monks who meditated were compared to student volunteers who had no previous experience with meditation. monks were found to have greater gamma wave action than the control group whilst meditating. this demonstrates short term changes in the functions of the brain. they were also found to have greater gamma activation before the meditation showing that there are more permanent changes.
Lazar et al - MRI scans demonstrated how experienced meditators had a thicker cortex than non meditators, particularly in areas related to attention and sensory processing.
Holzel et al - individuals took part in an 8 week mindfulness based stress reduction course and showed an increase in grey matter in the left hippocampus associated with learning and memory
Tang et al - four weeks of meditation resulted in an increase in white matter in the anterior cingulate cortex, a part of the brain that contributes to self regulation and control
functional recovery
a form of plasticity
brain has ability to redistribute or transfer functions usually performed by a damaged area to other undamaged areas
process can occur quickly (spontaneous recovery) and then slow after several weeks or months and the individual may require rehabilitation
the brain rewires and reorganises itself by forming new synaptic connections close to the area of damage. secondary neural pathways that would not typically be able to carry out certain functions are activated to enable functioning to continue
structural changes
axonal sprouting
- the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
reformation of blood cells
recruitment of homologous (similar) areas
on opposite side of the brain to perform specific tasks eg. damage to brocas area on the left of the brain could mean that the right side equivalent would carry out it's functions temporarily
evaluation
strength - it has practical application of contributing to neurorehabilitation. techniques include movement therapy and electrical stimulation. this shows the process needs intervention for patients to fully recover
limitation - it can have maladaptive behavioural consequences. Medina et al found that prolonged drug use results in poor cognitive functioning and a risk of dementia. this shows that plasticity and functional recovery can have some damaging effects
strength - plasticity tends to reduce with age however, Bezzola demonstrated how 40 hours of gold training produced changes in the neural representation of movement in participants aged 40-60. this shows that plasticity does continue throughout our life-span
strength - animal studies provide early evidence for functional recovery and plasticity. Hubel and Wiesel sewed one eye of a kitten shut. they found that the visual cortex of the shut eye was still processing information from the open eye as it was moving behind the eye lid. this shows that animal studies offer a basis for the theory. HOWEVER ANIMAL STUDIES CANNOT ALWAYS BE GENERALISED TO HUMANS