plasticity & functional recovery

• plasticity


  The brain can change throughout life
• synaptic pruning


  As we get older synaptic connections that we don't need shrink and the ones we use frequently are strengthened
• Maguire et el (2000)


  - Studied the brains of London taxi drivers who took a knowledge test which showed they had more neurons in the posterior hippocampus.

  - This was the part of the brain associated with navigational skills

  - Those who were taxi drivers for longer the more pronounced the structural difference was
• Draganski et al (2006)

  - Imaged the brains of medical students 3 months before and after their final exams

  - Learning-induced changes were seen to have occurred in posterior hippocampus and parietal cortex
• Mechelli et al (2004


  - Found larger parietal cortex in the brains of people who were bilingual compared to matched monolingual controls
• Lazar et al (2005)


  Using MRI scans showed that experienced meditators had a thicker cortex than non-meditators, in areas related to attention and sensory processing
• functional recovery of the brain


  Healthy brain areas take over the functions of the damaged/destroyed areas
• Synaptic Connections (functional recovery of the brain)


  The brain forms new synaptic connections close to the area of damage.
• Axonal Sprouting (functional recovery of the brain)


  Growth of new nerve endings which connect to other undamaged nerve cells to form new pathways.
• Reformation Of Blood Vessels (functional recovery of the brain)


  New blood vessels grow.
• Recruitment Of Homologous Areas (functional recovery of the brain)


  On the opposite side of the brain after a period of time,function may switch to the original side.
• AO3 = Practical Application (strength)

  - Research has helped in the area of neurorehabilitation

  - Spontaneous recovery slows down after a while so physical therapy may be necessary

  - Techniques such as movement therapy and electrical stimulation can be used to counter the deficits in motor and cognitive functioning after a stroke (example)
• AO3 = Negative Plasticity (weakness)


  When the brain rewires itself it can have negative consequences. For example, prolonged drug use has been shown to result in poorer cognitive functioning and an increased risk of dementia.

  
  

  60%-80% of amputees experience phantom limb syndrome sensations in the missing limb which can be painful. This is thought to be due to cortical reorganization in the somatosensory area as a result of limb loss.
• AO3 = Age and Plasticity (weakness)


  Functional plasticity reduces with age. As we get older we don't need to adapt to new experiences as much.
• AO3 = Age and Plasticity Bezzola et al 2012 (strength)


  It showed that 40 hours of golf training produced changes in the motor cortex of ppts aged 40-60, it used MRI scans to show that neutral plasticity does continue throughout life.
• AO3 = Support From Animal Studies (strength)

  Hubel & Wiesel (1963) - sewed 1 eye of a kitten shut and analysed the brain's response. The visual area associated with the shut-eye was not ideal but continued to process information from the open eye.
• AO3 = The Concept Of Cognitive Reserve (strength)

  - A person's educational attainment may have an influence on how well the brain recovers after trauma.

  Schneider et al (2014) - found that the more time brain injury patients spent in education the greater chance of disability-free recovery

  - 2/5 of patients who achieved disability-free recovery had more than 16 years of education