Plasticity

Question 1

What is plasticity?

Answer 1

The ability to replace the function lost by anatomical damage. It makes us question localisation and lateralisation

Question 2

What are the 3 main anatomical ways to replace axon function after trauma?

Answer 2

Increased brain stimulation, axon sprouting and denervation supersensitivity

Question 3

What is increased brain stimulation?

Answer 3

As neurons are damaged there is an effect on the neighbouring neurons as they no longer have input. Therefore if the damaged neurons are stimulated recovery can occur

Question 4

What is axon sprouting?

Answer 4

When an axon is damaged, other axons that already connect with that neuron will sprout extra connections to the neuron, replacing the ones that have been destroyed. It helps to replace function but if the damaged axon and the compensatory axons do a similar job

Question 5

What is denervation supersensitivity?

Answer 5

The axons that do a similar job become aroused to a higher level to compensate for the ones that are lost

Question 6

What is functional recovery of the brain?

Answer 6

Healthy brain areas may take over the functions of those areas that are damaged, destroyed or missing

Question 7

What are the four factors that affect recovery of the brain?

Answer 7

Perseverance, physical exhaustion, stress and alcohol consumption, age and gender

Question 8

How does perseverance affect recovery?

Answer 8

Sometimes a function may appear to be lost but that may be because the individual affected may not be trying and takes the view that it is unrecoverable

Question 9

How does physical exhaustion, stress and alcohol consumption affect recovery?

Answer 9

Function is used with considerable effort and can fatigue by the effort

Question 10

How does age affect recovery?

Answer 10

There is deterioration of the brain in old age so there is likely to be more regained function in younger patients

Question 11

How does gender affect recovery?

Answer 11

Women recover better from brain injury as their function is not as lateralised

Question 12

What are two strengths of plasticity?

Answer 12

Rehabilitation programmes are successful and Hubel and Wiessel found that shut eye was not active but it continued to process information

Question 13

What re three limitations of plasticity?

Answer 13

No record of functioning level prior to trauma, case studies vary so generalisation is hard and the ability to retire itself can have negative behavioural consequences eg phantom limb syndrome