Plasticity Flashcards
Plasticity
-Synaptic connections are formed and are pruned
-During infancy, the brain experiences a rapid growth in synaptic connections, peaking at about 15,000 at age 2-3 years
-As we age, rarely-used connections are deleted and frequently-used connections are strengthened- synaptic pruning
-It was once thought that 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
Maguire Et Al.
-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 of spatial and navigational skills
-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 on the job, the more pronounced was the structural difference.
Draganski Et Al.
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 for the exam.
A03 (Possible Negative Behavioural Consequences)
E- The brain’s adaptation to prolonged drug use leads to poorer cognitive functioning in later life, as well as an increased risk of dementia. 60-80% of amputees have phantom limb syndrome (experience sensations in missing limb due to changes in somatosensory cortex).
E- This suggests that the brains ability to adapt to damage is not always beneficial and may lead to physical and psychological problems
A03 (May Be A Lifelong Ability)
E- Ladina Bezzola et al. demonstrated how 40 hours of golf training produced changes in the neural representations in participants aged 40-60. Using FMRI, motor cortex activity in the novice golfers reduced compared to a control group, suggesting greater efficiency after training.
E- This shows that neural plasticity can continue throughout the lifespan.
A03 (Seasonal Brain Changes)
E- Seasonal plasticity occurs on response to environmental changes, e.g. the suprachiasmatic nucleus (SCN) shrinks in spring and spends in Autumn. However, much of the work on seasonal plasticity has been done on animals, most noticeably songbirds. Human behaviour may be controlled differently.
E- This suggests that animal research may be a useful starting point but can’t simply be generalised to humans
