Plasticity and functional recovery

• Plasticity


  The brain's tendency to change and adapt as a result of experience and new learning
• Brain Plasticity Infancy

  • Brain experiences rapid growth in the number of synaptic connections it has
  • Peaking at 15,000 synapses per neuron at 2-3 years
• Brain Plasticity Adulthood

  • Around 7,000 synapses
  • Connections we don't use are deleted and the ones we use are strengthened- synaptic pruning
  • Synaptic pruning enables lifelong plasticity where new neural connections are formed in response to new demands on the brain
• Research into plasticity: Taxi Drivers

  • There were 16 right handed male taxi drivers (average 14 years experience) compared with 50 right handed male non taxi drivers
  • Scanned PPs with an MRI machine
  • Found a significantly larger volume of grey matter in the posterior hippocampus in taxi group than control group
  • Taxi drivers experienced more plasticity than non taxi drivers and the more experienced the more pronounced the brain was
• What is the posterior hippocampus responsible for?

  Spatial and navigational skills
• Plasticity Rat research

  • 2 groups: Group 1 had 2 rats were in cage and Group 2 had 12 rats in a complex environment with things like a tunnel and wheel
  • Results found rats in Group 2 had more neurons in the brain
  • This suggests the brain can change as a result of life experiences
• What is a limitation of the research on rats?

  • Differences between rats and humans in terms of interactions and language
  • Humans have more complex behaviours compared to rats
• Evidence for plasticity: Video Games

  • One group played Super Mario for 30 mins a day for 2 months where the other group played no games at all
  • 2 months later they used an MRI for all PPs
  • They found the video game group had significant increase in grey matter in hippocampus where the other group had no differences
  • Playing the video games created new synaptic connections
• AO3 Plasticity: Negative Plasticity

  • Plasticity may have negative behavioural consequences
  • The brain's adaptation to prolonged drug use leads to poorer cognitive functioning in later life and increased risk of dementia
  • This suggests that the brains ability to adapt to damage is not always benefitial
• AO3 Plasticity: Age and Plasticity

  • A strength of plasticity is that is does not decline sharply with age
  • One study explored one group of 11 PPs ages 40-60 years and they had 40 hours of golf practice compared to a control group that had no experience
  • PPs had brains scanned with an fMRI
  • There is increased motor cortex activity in the golf group
  • Plasticity can continue through your lifespan
• AO3 Plasticity: Practical Application

  • Understanding the neuroplasticity of the brain has lead to the development of neurorehabilitation
  • Such as movement therapy
  • This has lead to discovering more about the brain
• What is functional recovery?

  A form of plasticity. When the brain recovers abilities that were previously lost due to trauma and functions move from damaged areas to undamaged areas
• Axonal Sprouting


  When undamaged axons grow new nerve endings to replace the old ones in order to reconnect to other neurons
• Neuronal unmasking


  When damage occurs dormant synapses become activated to take on the function that was lost because of brain damage
• Recruitment of homologous areas


  When similar areas sometimes in the other hemisphere are used when an area of the brain is damaged.
• Study to support functional recovery

  • Jody had extreme seizures to the point the doctors decided to remove her right hemisphere
  • Her brain reorganised itself and the functions she lost from her right hemisphere, her left hemisphere took control instead
• Factors affecting functional recovery

  1. Age- the younger you are the more plastic the brain is so it is easier to recover
  2. Education - the advanced your education is the more likely you are to recover
• AO3 Functional Recovery: Real World Application

  • Understanding processes involved in plasticity has contributed to neurorehabilitation
  • Understanding axonal growth encourages new therapies to be tried
  • Movement therapy is used with stroke patients
  • Research into functional recovery is useful as it helps medical professionals know when interventions need to be made
• AO3 Functional Recovery: Cognitive Reserve

  • The level of education may influence recovery rates
  • The more time people with a brain injury spent in education, the greater their chances of a disability free recovery
  • 40% achieved DFR had more than 16 years of education compared to 10% who had less than 12
  • People with brain damage who have insufficient DFR are less likely to achieve a full recovery