brain plasticity

• what is brain plasticity?

  • brains ability to change & adapt to experience & new learning
  • affected by personal experiences: what you pay attention to & what you find important
• is the brain malleable?

  yes
• gaprick et al 1999?

  • during infancy brain experiences rapid growth in number of synaptic connections due to amount of milestones we achieve in first few years of life
  • peaks at approximately 15000 between ages of 2-3
• what is synaptic pruning?

  • connections that are not used anymore are deleted
  • connections that are constantly used are strengthened
• maguire 2000 brain plasticity aim?

  • to examine whether structural changes could be detected in brains of people with extensive experience of spatial navigation
• maguire 2000 method?

  • used fmri scans
  • 16 right handed london taxi drivers (drove over 1.5 years)
  • 50 healthy right handed who did not drive taxis
• maguire 2000 findings?

  • taxi drivers had more grey matter (more neural connections) in posterior hippocampus compared to control
  • the longer the drivers had the job the more structural differences they had in brain
  • positive correlation
  • role of hippocampus is to facilitate spatial memory/navigation
  • experience directly influences brain & that it has ability to change in response
• what is functional recovery?

  • form of brain plasticity
  • when brain experiences trauma unaffected areas are able to adapt & change to compensate for damaged/destroyed/missing areas
  • immediate but not long lasting
  • patient would have rehabilitative therapy to recover further
• types of functional recovery?

  1. neural reorganisation
  2. neural regeneration
• how does age affect functional recovery?

  • if you are younger its easier to recover from trauma as less synaptic pruning has occured
• teuber?

  • found that soldiers with brain damage were more able to recover from movement & visual problems if they were under age of 20
  • recovery was much more difficult if they were older
• neural reorganisation?

  • functions that are lost due to damage are transferred to undamaged areas
  • brain reorganises itself
  • redistributes jobs to ensure all functions are being supported
• neural regeneration?

  • where something new is grown
  • can occur in 2 ways: neural growth & axonal sprouting
• neural growth?

  • when new neurones grow whole new axon to compensate for damage
• axonal sprouting?

  • forming new neural connections close to area of damage
  • brain able to grow new nerve endings which connect with other undamaged nerve cells to form new pathways
• 3 * of brain plasticity & functional recovery?

  1. evidence to support brain plasticity from bezzolla
  2. evidence to support plasticity from hubel & weisel
  3. practical application leading to neurohabilitation
• 2 X of brain plasticity & functional recovery?

  1. huge differences in terms of plasticity & functional recovery
  2. plasticity has negative effects on people
• * evidence to support from bezzolla?

  • found that brains of p aged between 40 & 60 changed after golf training
  • those that were given 40 hours of training had more activity in their motor cortex compared to control
  • if a skill that uses certain neural connections in brain is carried out alot these connections strengthen (increased grey matter).
  • shows that brain can adapt based on experiences to meet demands of individual through process of synaptic pruning
• * evidence to support from hubel & weisel?

  • did research on kittens which involved sewing 1 eye shut to see how visual cortex would respond
  • found that kittens were able to process info from open eye
  • shows when 1 functional area of brain is lost other areas can recover this function to compensate.
  • shows that another area can carry out this function through process of neural reorganisation
• * practical application?

  • although brain can rewire itself soon after trauma this process slows down after few weeks
  • means patients need further support to recover
  • neurohabilitation is form of physical therapy on brain - used to help patients recover & improve functioning
  • eg use techniques like electrical stimulation of brain to deal with damaged areas
  • has great success in helping lives of patients who have suffered trauma as result of injury/illness.
  • research has allowed for new successful techniques to be developed
  • has positive impact on patients & families
• X differences in terms of plasticity & fr?

  • ability of brain to recover varies depending on extent/location of damage & individual
  • eg characteristics (psych/physical/age) of patient influences recover ability
  • younger ppl more likely to recover compared to old
  • 1 individual may suffer same type of damage as another but both may not recover
  • individual differences between ppl means likelihood of fr can vary as persons level of plasticity is unique
  • population
  • level of recovery not going to be same for every person
  • idea that brain always recovers through nr cannot be generalised to entire pop
• X plasticity has negative effects on people?

  • research found that approx 60-80% amputees developed phantom limb syndrome
  • means continue to feel sensation of limb even though not part of them
  • unpleasant & painful - caused by changes in somatosensory cortex when limb lost
  • brain helps compensate for damaged areas have no control over when/how it occurs.
  • traumatic for patient - personally suffer from changes in brain through false belief that limb still present due to physical sensation brain produces
  • ? practicality as research suggests doesnt always have + impact on behaviour & psych wellbeing