Plasticity

Question 1

what is plasticity

Answer 1

This describes 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

plasticity as we age

Answer 2

During infancy, the brain experiences a rapid growth in the number of synaptic connections it has, peaking at about 15,000 per neuron at 2-3 years old. As we age, rarely-used connections are deleted and frequently-used connections are strengthened, this is known as synaptic pruning.

Question 3

what is synaptic pruning

Answer 3

As we age, rarely-used connections are deleted and frequently-used connections are strengthened. Synaptic pruning allows lifelong plasticity where new neural connections are formed in response to new demands on the brain.

Question 4

research into plasticity

Answer 4

Maguire et al (2000) studied the brains of London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than in a matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. Maguire et al found that the learning experience of London taxi drivers alters the structure of the taxi drivers’ brains. They also found the longer the taxi drivers had been on the job, the more pronounced the structural difference was – this is a positive correlation.

Question 5

Evaluation of plasticity (brief)

Answer 5

strength - Bezzola, life long ability
weakness - negative behavioural consequences

Question 6

strength of plasticity

Answer 6

one strength is that brain plasticity may be a life-long ability. In general plasticity reduces with age. However, Bezzola et al (2012) demonstrated how 40 hours of golf training produces changes in the neural representations of movement in participants aged 40-60. Using fMRI, the researchers observed increased motor cortex activity in the novice golfers compared to a control group. This suggests more efficient neural representations after training showing that neural plasticity can continue throughout the lifespan.

Question 7

weakness of plasticity

Answer 7

one limitation of plasticity is the negative behavioural consequences. Evidence has shown the brain’s adaption to prolonged drug use leads to poorer cognitive functioning in later life, as well as an increased risk of dementia. Also, 60-80% of amputees have been known to develop phantom limb syndrome. These sensations are usually unpleasant, painful and thought to be due to cortical reorganisation in the somatosensory cortex that occurs as a result of limb loss. Therefore, this suggests that the brain’s ability to adapt to damage is not always beneficial.