Plasticity and functional recovery of the brain

Question 1

Plasticity

Answer 1

The brain’s ability to modify its own structure and function as a result of experience - generally involves the growth of new connections
- Number of synaptic connections is huge during infancy but overtime reduces as rarely-used connections are deleted and frequently-used connections are strengthened (Synaptic pruning)

Question 2

Research into plasticity

Answer 2

• Eleanor Maguire
• Studied brains of London taxi drivers - found that they had significantly more volume of grey matter in the posterior hippocampus compared to a control group
• hippocampus associated with development of spatial and navigational skills
• Taxi driver took a complex test - assesses recall of streets and routes
• MRI scan obtained - 16 right handed male drivers participated - all had been driving for more than 1.5 years - scans of 50 healthy right handed non-taxi drivers acted as a control group
• Results:
• This alters structure of taxi drivers brains - increased grey matter - the longer taxi drivers had been in the job, the more pronounced the structural difference was (positive correlation)

Question 3

Functional recovery

Answer 3

An example of plasticity
- Following damage through trauma, the brain transfers functions usually performed by a damaged area to an undamaged area
- This is spontaneous recovery which then slows down and requires rehab
- Secondary neural pathways that wouldn’t typically be used for this function, are unmasked and activated to enable functioning to continue
- Process is supported by a number of structural changes
- 1) Axonal sprouting - new nerve endings connect with other nerve cells to form neuronal pathways
- 2) Reformation of blood vessels
- 3) equivalent area on opposite hemisphere takes on the function

Question 4

Plasticity - evaluation - strength

Answer 4

• May be a lifelong ability
• plasticity reduces with age but researchers found many hours of golf training produced changes in the neural representations of movement in p’s aged 40-60 - using fMRIs researchers observed reduced motor cortex activity in the golfers compared to a control group
• Shows plasticity can continue throughout lifespan

Question 5

Plasticity - evaluation - limitation

Answer 5

• May have negative behavioural consequences
• research has shown plasticity has led to poorer cognitive functioning in later life as well as increased risk of dementia
• Suggests brain’s ability to adapt isn’t always beneficial

Question 6

Functional recovery - evaluation - strength

Answer 6

• Real world application
• has contributed to neurorehabilitation
• e.g constraint-induced movement therapy is used with stroke patients where they practice using the affected body part while the unaffected part is restrained
• shows its usefulness in medical treatments

Question 7

Functional recovery - evaluation - limitation

Answer 7

• Level of education may influence recovery rates
• researchers found that the more time people with a brain injury had spent in education, the greater their chances of a disability free recovery (DFR)
• would imply people with brain damage who have insufficient DFR are less likely to achieve a full recovery