Plasticity and Functional Recovery

Plasticity definition

Describes the brains tendency to change and adapt as a result of experience and new learning- involves the growth of new connections

Functional recovery definition

The brains ability to redistribute or transfer functions usually performed by damaged areas of the brain to undamaged areas of the brain- form of plasticity

Synaptic pruning

As we age rarely used connections are deleted and frequently used connections are strengthened

Research into plasticity

• Maguire et al (2000)- studied the brains of London taxi drivers and found significantly more volume of grey matter than a control group

• As part of their training London cab drivers must take a complex test which assesses their recall of city streets and possible routes. The longer the taxi drivers had been in the job the more pronounced was the structural difference

functional recovery after brain trauma

• Functional recovery that occurs after trauma is an example of neural plasticity

• Occurs quickly after trauma then slows down after several months (may need rehabilitative therapy)

What happens in the brain during recovery

• Axonal sprouting

• Denervation super sensitivity

• Recruitment of homologous areas

Axonal sorouting

The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

Denervation super sensitivity

Occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. However it can have the negative consequence of over sensitivity to messages such as pain

Recruitment of homologous areas

a process where the opposite, undamaged hemisphere takes over the specific tasks of a damaged brain region

Evaluation of plasticity

• plasticity may have negative behavioural consequences. Evidence shows that prolonged drug use cause the brain to adapt and leads to poor cognitive function and increased risk of dementia.

• Brain plasticity could be life long

• London black cab drivers

Evaluation of functional recovery

• real world application - neurohabilitation simply understanding axonal growth is possible encourages new therapies to be tried eg: constraint endured movement therapy is used with stroke patents where by they repeatedly practise using the affected part of their body

• Cognitive reserve- Eric Schneider et al (2014) revealed that the more time people with a brain injury had spent in education the higher their chance was at having a disability free recovery was.

Factors affecting functional recovery

Age- younger people’s capacity for neural reorganisation is greater than older

Age

• Elbert et al concluded that the capacity for neural reorganisation is much greater in children than it is for adults meaning that neural regeneration is less effective in older brains

• This may explain why adults find change more demanding