plasticity and functional recovery

• what is brain plasticity?

  Brain Plasticity refers to the brains ability to modify its own structure and function as a result of experience.
• maguire study:

  studied the brains of London taxi drivers

  using an MRI and found significantly more grey matter in the

  posterior hippocampus than in the matched control group. 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.
• what does plasticity lead to?

  strengthening your brain - the more you use it the greater the neural connections / gamma waves / grey matter
• how do you build a cognitive reserve by:

  1. life experience - frequently used pathways gain strength. OLD THINKING - a natural decline in cognitive functioning declines as we age
• You build a cognitive reserve by:

  2- Video games - these increase grey matter due to using complex cognitive and motor actions which results in greater synaptic connections between spatial awareness and planning in working memory
• you build a cognitive reserve by:

  3- Meditating - Tibetan Monks that meditate have higher levels of gamma waves
• evaluation

  + Kempemann - Rats housed in enriched environments had increased neurons in the hippocampus as well as the ability to navigate from one location to another - compared to rats raised in impoverished environments -> Animal research - caution
• Human studies - Maguire extra

  • Control group allows us to say that there is a significant difference between taxi drivers and others
  • use of scientific, objective measurements
  • an attempt to study a real world phenomena
  • (-) we can’t be sure that the difference is due to the knowledge, they weren’t tested before. they could have been taxi drivers because of their already existing difference
• what is functional recovery?

  moving functions from a damage area to an undamaged area AFTER TRAUMA

  healthy brain areas may take over the functions of those areas that are damaged
• Spontaneous recovery is initially quick but slows down -> Leads to the need for rehabilitation
• methods of Functional recovery

  1. Neural masking - dormant areas in your brain become unmasked, new neural pathways are forced down dormant areas and become activated
  2. Stem cells - implanted from bone marrow which either replace the dead, rescue the dying or act as a link between living and dying
• what is Axon Spouting?

  growth of new nerve endings, connect with undamaged nerve endings to form new neural pathways
• what is denervation supersensitivity?

  axons that do a similar job become aroused to a higher level to compensate for ones lost
• what is recruitment of homologous area?

  the opposite hemisphere can be useful -> Case of J.W - learned to speak out of right hemisphere after trauma
• evaluation strength - Tajiri

  • Rats with brain injury assigned to stem cells or placebo
  • after 3 months stem cell rats showed development of neuron-like cells in brain injury area
  • (+) animal studies allow us to look at before and after trauma to see the difference which isn’t ethical to humans
• evaluation - age

  • the belief that the ability to functionally recover decreases with age. sometimes compensatory strategies are needed to help recovery -> neurorehabilitation
• evaluation - Schneider

  • People with equivalent of a college education are 7x more likely to be disability free after one year of trauma -> education creates a cognitive reserve allowing neural adaptation needed for recovery
• when answering a plasticity and functional recovery question what must you refer to in your answer?

  the person’s age