Plasticity

Question 1

What is meant by plasticity?

Answer 1

The brain’s ability to adapt and change over time as a result of new experience and learning. As we age, connections that are really used are removed and frequently used connections are strengthened (synaptic pruning)

Question 2

Maguire (2000)

Answer 2

MRI scan showed taxi drivers had higher volume of grey matter in posterior hippocampus than matched control group. Positive correlation between size of posterior hippocampus and time as a taxi driver

Question 3

Functional recovery

Answer 3

Following injury or trauma the brain is able to adapt and compensate through transfer of functions to undamaged areas (neural reorganisation) and growth of new neurons and connections (neural regeneration)

Question 4

Structural changes

Answer 4

• Axonal sprouting (growth of new nerve endings)
• Reformation of blood vessels
• Denervation super-sensitivity (axons more responsive)

Question 5

Strengths of plasticity

Answer 5

• Case study evidence (eg. After removal of LH at 2, by 17 EB developed near-normal language abilities, with his RH compensating for the loss)
• Supportive evidence (eg. Rosenweig found rats in enriched environments developed thicker cortex and heavier frontal lobes than impoverished over 30-60 days)

Question 6

Limitations of plasticity

Answer 6

• Individual differences (eg. Multitude of research showing younger patients, women and patients who spent more time in education have better functional recovery)
• Negative outcomes (eg. Medina found prolonged drug use can result in poorer cognitive functioning and dementia in later life. Also 70% of amputees experience phantom limb pains)