Plasticity And Functional Recovery Of The Brain

Question 1

Define plasticity

Answer 1

Describes the brains tendency to change and adapt as a result of experience, new learning or training - also referred to as neuroplasticity/ cortical remapping

Question 2

Define structural plasticity

Answer 2

The brain physically changes eg in size and volume

Question 3

Define functional plasticity

Answer 3

The brain changes its purpose eg anterior hippocampus taking on the procedural skills from the posterior hippocampus

Question 4

Define recruitment of homologous areas

Answer 4

The equal but opposite area of the brain is taken over to perform a particular function

Question 5

Define neuronal unmasking

Answer 5

When the brain reorganises itself by forming new synaptic connections close to the area of damage

Question 6

Define axonal sprouting

Answer 6

The growth of new nerve endings which connect with other undamaged nerve cells to produce new neural pathways

Question 7

KEY STUDY - Maguire et al study into plasticity

Answer 7

Maguire looked at the MRI scans of 16 right handed London taxi drivers and 50 right handed non taxi drivers. As part of training, London taxi drivers have to take a complex test called ‘The Knowledge’ which assesses recall of around 20,000 street names and locations in London. To calculate the size of their hippocampus, voxel pixel counting was used (number of squares in image). There was more volume of grey matter in the posterior hippocampus than the control group and the posterior hippocampus had taken over some of the anterior hippocampus. Thus proving structural plasticity.

Question 8

EVALUATION - does the brain have plasticity?

Answer 8

PEEL 1 - One limitation is there are criticisms of Maguires research - sample bias and no brain scan before and after test - cannnot be sure the size of posterior increased due to knowledge test and may have already been larger

PEEL 2 - However Maguire did overcome this criticism - did the same study but compared the hippocampi before and after test and found it did increase after test - shows cause and effect

PEEL 3 - On the other hand there are individual differences in level of plasticity - age ( over 40 years plasticity decreases), gender (females have more plasticity in wernickes and brocas), education (undergraduates students recovered more function than high school graduates) - plasticity differs person to person.