Plasticity and Functional Recovery

• Plasticity


  The brain's ability to alter both its structure and function
• Plasticity


  • Important for learning and for recovery after trauma
• Plasticity


  1. Impulses travel along neurons and travel to the next neuron via a synapse

  2. Neural pathways are created as new information is passed from one neuron to another

  3. The more these neural pathways are used, the stronger the pathway becomes

  4. If the pathway is not used regularly, the connection weakens
• Plasticity happens not only in babies and children, but in adults as well
• Adults who have had brain damage have been able to recover the loss of function
• Functional recovery after trauma


  The brain can rewire and reorganise itself after damage
• Brain damage


  • Stroke
  • Injuries
  • Tumours
  • Infections
• If a stroke patient has damage to the area of the brain that controls the left hand, then healthy areas around the damaged part can take over that function
• Split-brain surgery


  Corpus callosum severed due to severe epilepsy
• Sperry (1968) research method

  1. Natural experiment

  2. 11 participants (10 men, 1 woman)

  3. Visual and tactile tests
• Information presented to the right visual field could be described in speech and writing, but if presented to the left visual field, the participant could not remember seeing anything and could not describe it
• Objects placed in the right hand could be described in speech or writing, but if placed in the left hand, participants guessed and sometimes seemed unaware they were holding anything
• These findings support the theory that for right handed people, language is processed in the left hemisphere of the brain
• Sperry (1968) research


  • Controlled and standardised - reliable
  • Small sample
  • Individual differences
  • Lack ecological validity
• Maguire et al (2000) research


  Studied London taxi drivers to discover whether changes in the brain could be detected as a result of their extensive navigational experience
• Maguire et al (2000) procedure

  1. Natural experiment

  2. Using an MRI scanner, the researchers calculated the amount of grey matter in the brains of taxi drivers and a set of control participants
• The posterior hippocampi of taxi drivers were significantly larger relative to those of controls and posterior hippocampal volume was positively correlated with the amount of time they had spent taxi driving
• This demonstrates brain plasticity. The structure of the brain can change in response to the demands placed upon it