plasticity and functional recovery

• What is plasticity?


  Brain plasticity refers to the brain's ability to change and adapt because of experience.
• What was the original belief regarding brain plasticity?

  It was originally thought that such changes were restricted to the developing brain within childhood and that the adult brain would remain fixed
• What does more recent research suggest about brain plasticity?

  That neural connections can change at any time or new neural connections can be formed as a result of learning and experience. However, plasticity does still reduce with age and therefore children will have more capacity for plasticity, but it is still possible in later life
• What is functional recovery of the brain?

  The transfer of functions from a damaged area of the brain after trauma to other undamaged areas.
• What happens during functional recovery?

  Following physical injury, or other forms of trauma such as a stroke, has seen unaffected areas of the brain are able to take over and compensate for the damaged areas
• What process does functional recovery happen through?

  Neuronal unmasking
• What is neuronal unmasking?

  'Dormant' synapses (which have not received enough input to be active) open connections to compensate for a nearby damaged area of the brain. This allows new connections in the brain to be activated, thus recovering any damage occurring in specific regions
• What happens during recovery?

  The brain can rewire itself and reorganise by forming new synaptic connections. Secondary neural pathways, that wouldn't normally carry out those functions are activated to enable functioning to continue
• What structural changes in the brain supporting functional recovery?

  Axonal sprouting, reformation of blood vessels, recruitment of homologous areas
• What is axonal sprouting?

  The growth of new nerve endings which connect with other undamaged nerve cells to form new pathways
• What is recruitment of homologous areas?

  Recruitment of similar areas on the opposite side of the brain to perform specific tasks.
• What is an example of recruitment of homologous areas?

  If Broca's area was damaged on the left side of the brain, the right side would then carry out its function. After recovery it would then shift back.
• Is functional recovery an active or passive process?


  Functional recovery of the brain is not a passive process and recovery is not always complete
• What does functional recovery depend on?

  The extent and location of damage and the level of subsequent care
• What are the factors affecting functional recovery?

  Age, gender, stress, alcohol consumption
• How does age affect functional recovery?

  There is a deterioration of the brain in old age, and this affects the extent and speed of recovery
• How does gender affect functional recovery?

  Research suggests that women recover better from brain injury as their function is not as lateralised (Ratcliffe et al., 2007).
• How does stress and alcohol consumption affect functional recovery?

  Can affect the ability to use any function that has been regained (Fleet & Heilman, 1986).
• Who conducted early evidence into plasticity and functional recovery?

  Hubel & Wiesel (1963)
• What did Hubel & Wiesel (1963) do?


  Sewing one eye of a kitten shut and analysing the brain's responses
• What did Hubel & Wiesel (1963) find?

  The area of the visual cortex associated with the shut eye wasn't idle as predicted but continued to process information from the open eye
• How does Hubel & Wiesel (1963) supporting plasticity and functional recovery?


  Areas of the brain that were not being used due to the eye being shut were then recruited for another use
• What is a counter-argument for Hubel & Wiesel (1963)?

  The human brain is different from most species in certain respects so how the animal brain shows plasticity may be different from how a human brain would show plasticity.
• Who conducted supporting evidence for plasticity and functional recovery in humans?

  Danelli et al. (2013)
• Who did Danelli et al. (2013) study?

  Assessed a 14-year-old patient known as EB who was born with a tumour in their brain
• What happened to EB?

  At the age of two, they underwent a left hemispherectomy (removal)
• What areas did EB's hemispherectomy remove?

  Broca's and Wernicke's area
• What did Danelli et al. (2013) find?

  EB lost nearly all their language capabilities after surgery, however, after two or so years, they regained nearly full use of their language abilities, although it was still more taxing for them mentally.
• What was shown using a fMRI of EB's brain?

  The right hemisphere had changed structurally, to the point of 'matching' a similar structure that language centres lost in the left hemisphere
• What did Schneider et al. (2014) discover?

  That the more time people with brain injuries had spent in education have greater 'cognitive reserve' which increases their chances of a disability-free recovery (DFR)
• How did Schneider et al. (2014) support their claims?

  39% of graduates were had a DFR whereas only 10% of those who left school early had