plasticity

Question 1

what is neural plasticity

Answer 1

describes the brain’s tendency to change and adapt (functionally and physically) as a result of experience and new learning.

Question 2

what happens during infancy

Answer 2

during infancy, the brain experiences a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 at age 2-3 years.

Question 3

what happens as we age

Answer 3

• As we age, rarely used connections are deleted and frequently used connections are strengthened- synaptic pruning.
• It was originally thought that plasticity occurred in infancy and childhood and the adult brain remains fixed and static.
• However, more recent research suggests that at any time in life, existing neural connections can change, or new neural connections can be formed, as a result of learning and experience.

Question 4

research into plasticity - M

Answer 4

Maguire et al. (2000)
o 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.
o This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training, London cabbies must take a complex test called ‘The Knowledge’, which assesses their recall of the city streets and possible routes.
o Maguire et al. found that this learning experience alters the structure of the taxi driver’s brains. They also found that the longer the taxi drivers had been in the job, the more pronounced was the structural difference (a positive correlation)

Question 5

research into plasticity - D

Answer 5

A similar finding was observed by Draganski et al. who imaged the brains of medical students three months before and after their final exams. Learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex presumably as a result of learning.

Question 6

evaluation plasticity

Answer 6

EVALUATION

NEGATIVE PLASTICTIY
P - One limitation of plasticity is that it may have negative behavioural consequences
E - Evidence has shown that the brain’s adaptation to prolonged drug use leads to poorer cognitive functioning in later life, as well as an increased risk of dementia (Medina et al. 2007). Also, 60-80% of amputees have been known to develop phantom limb syndrome - the continued experience of sensations in the missing limb as if it were still there. These sensations are usually unpleasant, painful and are thought to be due to cortical reorganisation in the somatosensory cortex that occurs as a result of limb loss.
E - This suggests that the brain’s ability to adapt to damage is not always beneficial

AGE AND PLASTICITY
P - One strength is that brain plasticity may be a life-long ability.
E - In general plasticity reduces with age. However, Bezzola et al. (2012) demonstrated how 40 hours of golf training produced 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, suggesting more efficient neural representations after training.
E - This shows that neural plasticity can continue throughout the lifespan.