Brain Plasticity + Functional Recovery

• what is brain plasticity?

  • brain adapting in both structure and function as a result of a change in environment e.g damage or cognitive demand
• reasons for brain plasticity?

  • learning a new skill
  • result of DEVELOPMENTAL CHANGE
  • direct trauma
  • indirect effects of damage e.g swelling from stroke
• what is functional recovery?

  • function that were performed by areas of the brain that are lost or damaged are performed by undamaged areas (aka functional reorganisation)
• what is synaptic pruning?

  • synapses that are used more frequently become stronger over time
  • unused synaptive connections are lost
  • this makes the brain a more efficient communication system over time
• what is axonal sprouting?

  • existing neurons growing new axons to connect adjacent neurons
  • neural regeneration is the growth of new neuronal cells
• what is denervation supersensitivity?

  • to compensate for the loss of axons in a pathway the remaining axons become more sensitive (so more likely to fire)
  • this can result in side effects such as pain
• what is recruitment of homologous area?

  • where the brain recruits similar regions in the opposite hemisphere to compensate for damaged areas
• what is constraint induced therapy?

  • stopping patients from using coping strategies (e.g body language to communicate, using only undamaged limbs for tasks)
  • this makes them improve via functional reorganisation
• Plasticity and Recovery research - Maguire et al. (2000)

  • structural MRI Brain scan for 16 taxi drivers compared to 16 matched non-taxi drivers
  • posterior hippocampi in taxi drivers significantly larger than control - size correlated to time spent as taxi drivers
  • suggests structure of brain is plastic and is able to reconfigure to adapt to psychological demand, in this case improving memory formation
• Plasticity and Recovery Evaluation - Real World Applicatio

  • strength - real world application to neurohabilitation knowledge of plasticity and how brain can recover after trauma has led to inventions which have made recovery better
  • constraint induced movement therapy involves trying to move the affected limb, rather than trying to overcompensate by using the unaffected limbs.
• Plasticity and recovery Evaluation - Cognitive Reserve

  • limitation - recovery after trauma is not as effective for everybody
  • Senneider found that patients who had 16 years of education had a higher recovery rate compared to patients who had 10 years of education
  • this indicates a 'cognitive reserve' which is higher for those with more education
• Plasticity and recovery Evaluation - negative plasticity

  • limitation : plasticity is that may have negative behavioural consequences
  • evidence has shown that the brain's adaptations to prolonged drug use leads to poorer cognitive functioning in later life, aswell as increased risk of dementia
  • this suggests the brain's ability to adapt to damage is not always beneficial
• Plasticity and recovery Evaluation -Age and plasticity

  • strength: brain plasticity may be a lifelong ability
  • in general plasticity reduces with age but Bezzola et al. (2012) found that 40 hours of golf produced changes in neural representations. using fMRI, he observed increased motor cortex activity in novice golfer compared to control group, suggesting more effcicent neural representations after training
  • this shows neural plasticity can continue throughout lifetime