Y13 Biopsychology - Plasticity and Functional Recovery Of The Brain Flashcards
What is brain plasticity?
The brain’s ability to change and adapt as a result of experience.
How are neural pathways formed and how are they strengthened?
1) Info takes a pathway through the brain, travelling from one neuron to the next via synapses.
2) New info = New neural pathways form.
3) The more you use a neural pathway the stronger it gets.
4) Neural pathways not used become weaker and die.
At what age does placticity happen?
- It was first believed that plasticity only takes place in infancy but it is now widely accepted that plasticity occurs throughout adult life too.
- Infancy = the most rapid growth in the number of synaptic connections, peaking at approx. 15,000 by the age of 2-3.
- The brain is in a continual state of change and refinement.
What was the method in Elbert et al (1995)?
9 musicians who played string instrument were compared to 6 non-musicians. Magnetic source imaging used to measure area of somatosensory cortex representing the digits of the left hand.
What were the results in Elbert et al (1995)?
The area of the somatosensory cortex representing the the digits of the left hand was larger in the stringed instrument players than in the control.
What was the conclusion in Elbert et al (1995)?
Findings suggest that the increased amount of sensory processing required from the left hand of the of the stringed instrument players results in structural changes in the brain, supporting plasticity.
Evaluate Elbert et al (1995).
- Provides real world support for plasticity.
- The increased representation of left hand digits in musician group could of been genetic not a result of playing the instrument.
- Small sample size.
What is functional recovery?
The transfer of functions from a damaged area of the brain after trauma to other undamaged areas. If a part of the brain gets damaged or destroyed other areas of the brain can learnt to perform particular functions that were lost.
What is meant by opposite side takes over?
Recruitment of homologous areas on the opposite hemisphere to do sepcific tasks that were lost. Example: Broca’s area was damaged so an area in the right hemisphere might take over.
(A diversion on roads)
What is meant by axonal sprouting?
New nerve endings grow and connect with undamaged areas to form new neural pathways.
What is meant by neural unmasking?
Dormant synapses are unmasked. Wall (1977) identified these. It is said that we all have them but due to low neural input they are never activated. However, increasing the rate of input to these synapses (which would happen when the surrounding area of the brain is damaged) would make the neural pathways stronger and could create new structures.
What method is used to encourage functional recovery?
Constraint-induced movement therapy (CIMT) - e.g. if someone has lost function in right arm they will be prevented form using their left arm in order to force them to ‘re-learn’ how to use their right arm.
What are the advantages of CIMT?
- Studies have shown it produces cortical reorganisation which results in regained or improved function.
- The core principle can also be applied to those who suffer from aphasia (forcing them to play a game that requires them to speak).
What are the disadvantages of CIMT?
- Can be very frustrating for the patient.
- It is very intensive. Patient required to train affected limb 7 hrs a day for consecutive weeks and have their unaffected limb restrained for 90% of the time they are awake.
- Most effective in treating patients who have suffered mild/moderate strokes. Harder to regain function if there is lots of damage to the brain.
What did Schneider et al find?
Patients with the equivalent of a college education are 7x more likely than those who didn’t finish high school to be disability-free one year after a moderate to severe traumatic brain injury.
