Plasticity and Functional Recovery

• Brain plasticity

  The capacity for the brain to alter its structure and function.
• Synaptic


  chemical release and diffusion across a synapse
• Maguire et al (2000)


  Aim: To investigate whether or not the hippocampus plays a role in human spatial memory

  
  

  Procedure: London taxi drivers with a range of age and experience were the participants because their work requires the extensive use of spatial navigational skills, matched pairs design: participants were age and gender matched with a control group, and two different types of MRI scanning were used to assess how the brains of the taxi drivers differed from the control group. It was a quasi-experiment

  Results: showed significantly more grey matter in both left and right hippocampi of the taxi drivers compared to the control group

  
  

  Evaluation:

  •No researcher bias

  •No ethical implications

  •Only observed males

  •Only observed 16 matched pairs

  •Nature vs. Nurture debate: did the driving influence the change in the hippocampus, or did their larger than average hippocampus lead them to become taxi drivers?

  
• Hippocampus


  A neural centre located in the limbic system that helps process explicit memories for storage.

  
• Control group


  In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

  
• Positive correlation


  - A correlation where as one variable increases, the other also increases, or as one decreases so does the other.

  - Both variables move in the same direction.

  
• Parietal cortex


  Brain region that processes information about sensation.

  
• Limitation of brain plasticity

  Negative plasticity

  - Ramachandran and Hirstein (1998) 60-80% of amputees develop phantom limb syndrome, which is believed to be a result of cortical remapping in the somatosensory cortex that occurs as a result of limb loss.
• Strength of brain plasticity

  Age and plasticity

  - Bezzola et al (2012) Using fMRI, researchers observed increased motor cortex activity in novice golfers compared to a control group.
• Functional recovery


  - A form of plasticity.

  - Following damage through trauma, the brain's ability to redistribute or transfer functions usually performed by a damaged area to other, undamaged areas.
• Axonal sprouting


  The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
• Denervation super sensitivity


  - To compensate for the loss of axons in a pathway the remaining axons become more sensitive (more likely to fire).

  - This can result in side effects such as pain.
• Recruitment of homologous areas

  Regions on opposite sides of the brain take on functions of damaged areas.
• Strength of functional recovery

  Real-world application

  - Understanding plasticity led to neurorehabilitation understanding axonal growth encourages new therapies E.g constraint induced movement therapy involves massed practice with an affected arm while unaffected arm is restrained, shows research into functional recovery helps medical professional know when interventions can be made.
• Limitation of functional recovery

  Cognitive reserve

  - Schneider et al (2014) Brain injury patients who had spent more time in education prior to their brain injury than other brain injury patients were more likely to make a disability free recovery (DFR).

  - This may be due to 'cognitive reserve' whereby the brain is better able to adapt after injury possibly due to experiences such as educational attainment