Plasticity and recovery of the brain

Question 1

The brain is ‘plastic’ - synaptic connections are formed and pruned.

During infacy, the brain experiences a rapid growth in synaptic connections, peaking at about 15,000 at age 2-3 years (Gopnik et al. 1999).

AO1: Plasticity

Answer 1

As we age, rarely-used connections are deleted and frequently-used connections are strengthened - synaptic pruning.

It was once thought these changes were limited to childhood but recent research suggests neural connections can change or be formed at any time, due to learning and experience.

Question 2

The concept of plasticity is supported by a taxi driver study.

Maguire et al. (2000) found significantly more volume of grey matter in the posterior hippocampus in London taxi drivers than in a matched control group. This part of the brain is linked with the development if spatial and navigational skills.

AO1: Plasticity

Answer 2

As part of their training, London cabbies take a complex test called ‘The Knowledge’ to assess their recall of city streets and possible routes.

This learning experience appears to alter the structure of the taxi drivers’ brains. The longer they had been in the job, the more pronounced was the structural difference.

Question 3

Plasticity is also supported by research on learning.

Draganski et al. (2006) imaged the brains of medical students 3 months before and after final exams.

AO1: Plasticity

Answer 3

Learning-induced changes were seen in the posterior hippocampus and the parietal cortex, presumably as a result of learning for the exam.

Question 4

Following trauma unaffected areas of the brain take over lost functions.

AO1: Functional recovery of the brain after trauma

Question 5

The brain ‘rewires’ itself by forming new synaptic connections.

AO1: Functional recovery of the brain after trauma

Question 6

Structural changes in the brain.

Axonal sprouting;

AO1: Functional recovery of the brain after trauma

Question 7

Structural changes in the brain.

Denervation supersensitivity;

AO1: Functional recovery of the brain after trauma

Question 8

Structural changes in the brain.

Recruitment of homologous (similar) areas;

AO1: Functional recovery of the brain after trauma