Plasticity and functional recovery of the brain

• Outline plasticity of the brain. 


  Plasticity refers to the brain’s ability to change its organisation and/or structure in response to experience.

  E.g. when a new skill is being learned, new neural pathways are created in the brain and, when that skill is practiced, those neural pathways strengthen. However, if that skill is no longer used, the neural pathway is weakened.

  The plasticity of the brain means that when it experiences trauma (e.g. injury), it can recover some of its functions.
• Outline neural regeneration. 


  One way is through neural regeneration whereby the damaged neurons will regrow or repair themselves.
• Outline neurogenesis. 


  Another way is through neurogenesis which refers to when the implantation of stem cells results in the development of new neurons. These can replicate rapidly to help overcome brain trauma.
• Outline axonal sprouting. 


  A final way of recovering from brain trauma is axonal sprouting which refers to when undamaged neurons grow new axon terminals so that they can connect

  with other undamaged neurons to form new neural pathways
• Evaluate the plasticity and functional recovery of the brain after trauma: supporting evidence. 


  E.g. an MRI study of London taxi drivers found they had more brain tissue in the posterior hippocampus (an area of the brain associated with navigational memory – remembering locations) than a control group of non-taxi drivers. This is a strength because it demonstrates how experience (taxi driving) can change the structure of the brain.
• Evaluate the plasticity and functional recovery of the brain after trauma: unable to establish cause and effect. 


  E.g. with regards to the taxi driver study, it could be argued that they already had increased brain tissue in that area. This could have resulted in better navigational memory which is why they chose to pursue the career of taxi driving. This is a limitation because it means that the increased brain tissue in the posterior hippocampus could be unrelated to the experience of taxi driving.
• Evaluate the plasticity and functional recovery of the brain after trauma: supporting evidence. 


  E.g. a researcher randomly assigned rats with brain injury to one of two groups: One group received transplants of stem cells into the damaged brain area while the other group received a solution containing no stem cells. It was later found that the rats that had received stem cells showed increased development of neurons in the area of their brain that was injured. This is a strength because it supports the proposal that the brain is able to recover through neurogenesis.
• Evaluate the plasticity and functional recovery of the brain after trauma: depends on individual differences.


  Younger people are more likely to recover from brain injury than older people because their brains are still maturing. Plasticity also allows the brain to cope better with the indirect effects of brain damage rather than a direct physical blow. The ability of the brain to recover depends on the extent of the damage, its location, and the lifestyle of the patient. These individual differences make it difficult to generalise the functional recovery of the brain.