Plasticity

Question 1

What is plasticity?

Answer 1

• Plasticity is the brains tendency to change and adapt as a result of experience and new learning. This generally involves the growth of new connections

Question 2

What happens to the human brain as an infant?

Answer 2

• During infancy, the brain experiences a rapid growth in the number of synaptic connections it has, peaking at 15,000 per neuron at 2 -3 years of age. this is twice as much as the adult brain.

Question 3

What is synaptic pruning?

Answer 3

• As we age, rarely - used connections are deleted and frequently - used connections are strengthened
• this enables life - long plasticity where new neural connections are formed in response to new demands on the brain

Question 4

What is the case study into plasticity?

Answer 4

• Eleanor Maguire studied the brains of London taxi drivers and found significantly more grey matter in the posterior hippocampus than in a control group
• This part of the brain is associated with the developments of spatial and navigational skills in humans and other animals.
• This is because, London cabbies have to take a complex test called the knowledge which assesses their recall of city streets and routes. They also found the longer they did the job, the more pronounced the structural differences in their brains
• Draganski imaged the brains of medical students three months after and before exams. They found that learning induced changes were seen to occur in the posterior hippocampus

Question 5

What is a strength of brain plasticity?

Answer 5

One strength is that brain plasticity may be a life long ability. In general, plasticity reduces with age. However, Bezzola et al demonstrated how 40 hours of golf training produced changes in neural representations of movement in participants aged 40 - 60. Using FMRI, reasearchers observed motor cortex activity in the novice golfers to a control group and found there were was a change in neural respresentation after training. This shows neural plascity occurs throughout life.

Question 6

What is a negative of plasticity?

Answer 6

• one limitation is that it may have negative behavioural consequences.
• Evidence has shown that the brains adaption to prolonged drug use leads to poorer cognitive functioning in later life
• Also, 60-80% amputees have been known to develop phantom limb syndrome. these have been known to be painful and unpleasant. This suggests plasticity is not always beneficial