Plasticity + Functional recovery

Question 1

What is plasticity?

Answer 1

This describes the brains tendency to change and adapt as a result of experience and new learning. This generally involves the growth of new connections.

Question 2

Brain plasticity in infancy?

Answer 2

Rapid growth of synaptic connections 15,000 per neuron at 2-3 years. Synaptic pruning enables life long plasticity where new neural connections are created in response to new demands on the brain.

Question 3

Research into plasticity?

Answer 3

Maguire et al (2000): studied the brains of London taxi drivers and found significant grey matter in the posterior hippocampus then in control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. Their recall of routes alters structural difference, longer in job more difference.

• Draganski: medical students before and after final exams learning induced changes in posterior hippocampus and parietal cortex as a result of their learning.

Question 4

What is functional recovery?

Answer 4

A form of plasticity follow damage through trauma, the brains ability to redistribute or transfer functions usually performed by a damaged area to other undamaged areas.

Question 5

When does FR occur and how quickly?

Answer 5

After trauma such as a stroke, this is neural plasticity. Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) then slow down after several weeks and months they may need rehabilitation therapy.

Question 6

What happens in the brain during recovery?

Answer 6

It is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage. Secondary neural pathways are unmasked allowing functioning to continue.

Question 7

What did Doige state the structural changes are

Answer 7

• Axonal sprouting- the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
• Denervation super sensitivity- this occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. It can have a negative consequence on messages like oversensitivity to pain

Question 8

What is the evaluation of plasticity?

Answer 8

• May have negative behaviour consequences, evidence has shown the brains adaption to prolonged drug use leads to poorer cognitive functioning and increased risk of dementia. 60-80% of amputees develop phantom limb syndrome sensations in missing limb due to cortical reorganisation in the somatosensory cortex, not always beneficial
• Brain plasticity may be a life long ability. General plasticity reduces with age. Bezzola et al demonstrates how 40 hours of golf training produced changes in the neural representations of movement in participants aged 40-60. Using fMRI they observed increased motor cortex activity in golfer over control group. Neural plasticity continue through life span.

Question 9

What is the evaluation of FR?

Answer 9

RWA: contributed to the field of neurorehabilitation, simply understanding that axonal growth is possible encourages new therapies to be tried. Constraint induced movement is used with stroke patients whereby they repeatedly practice the affected part of their body. Helps medical professionals

Level of education may influence recovery rates. Schneider et al more time people with brain injury had spent in education, greater chance for a disability free recovery. 40% DFR more than 16 years educations. 10% less than 12 years.