Brain Plasticity and Functional Recovery

• Brain plasticity:

  • this is the brain's ability to change and adapt throughout life as a result of experience and new learning
  • this will be affected by what you personally experience in your life, what you pay attention to and what you find important
  • plastic is something that can continually change, which is where the name comes from
• Synaptic pruning:

  • the brain is made up of millions of synaptic connections that continually change. As you get older brain connections that are not used anymore are deleted and those connections that are used a lot are strengthened. This is called synaptic pruning
  • the process of getting rid of unused connections is called the 'use it or lose it' principle
• Maguire's research into brain plasticity - procedure (2000):

  • Maguire studied the brains of London taxi drivers. As part of their training to be a taxi driver, they have do to a very complex test, which asks them to recall many city streets and possible routes around London. This is known as 'The Knowledge'
  • she used fMRI scanners to scan the brains of taxi drivers and compare them them to non-taxi drivers. This is an example of cognitive neuroscience
• Maguire's research into brain plasticity - findings (2000):

  • she found that the taxi drivers had more grey matter in the posterior hippocampus compared to the control group of non-taxi drivers. This part of the brain has been linked to memory and spatial and navigational skills in humans and animals
  • she also found that the longer the taxi drivers has been in the job, the more structural differences they had in the brain
  • therefore, she found a positive correlation between time spent driving a taxi and hippocampus size
• Maguire's research into brain plasticity - conclusion (2000):

  • this shows that experience directly influences the brain and that it has the ability to change in response to it
  • in other words, showing evidence of brain plasticity
• Functional recovery:

  • functional recovery is a form of brain plasticity
  • when the brain experiences trauma, for example due to an injury or a stroke, the unaffected areas of the brain are able to adapt and compensate for the areas that are damaged
  • healthy brain areas take over the functions of those areas that are damaged, destroyed or even missing. This process can occur quickly after trauma but then slows down after several weeks or months. The patients would then need rehabilitative therapy to recover further. Functional recovery is not a purely passive process that happens on its own
• Recovery:

  • this happens via a process called neuronal unmasking. This is where dormant synapses compensate for damaged areas of the brain
• Types of functional recovery:

  • neural reorganisation
  • neural regeneration
• Neural reorganisation:

  • this is where functions that are lost due to damage are transferred to undamaged areas
  • for example, the right hemisphere may attempt to take on some language functions if the left was damaged
  • this is known as the recruitment of homologous regions
• Neural regeneration:

  • this is when new neurons grow to compensate for the damage and/or when new connections between neurons are made
  • one way this is done is called axonal sprouting. The brain is able to form new synaptic connections close to the area of damage
  • the brain is able to grow new nerve endings which connect with other undamaged nerve cells to form new pathways
• Factors affecting functional recovery:

  2 factors that affect functional recovery are;

  • age
  • education
• Age:

  • it is easier to recover from trauma if you experience brain trauma when you are young. Children will recover more than adults will
  • Teuber (1975) found that soldiers with brain damage were more able to recover from movement and visual problems if they were under the age of 20. This recovery was much more difficult if they were older
  • this is because when you are younger you have experienced less synaptic pruning, meaning you have more neurons to unmask and take over the jobs of the damaged areas. When you are older you may have already lost these connections via synaptic pruning
• Education:

  • it is easier to make a full recovery if you have spent longer in education
  • this is because the longer you have been in education the less likely you are to have had extensive synaptic pruning (you are using your brain more, therefore losing fewer connections). This is known as 'cognitive reserve'
  • Schneider et al (2014) found that the longer someone had spent in education, the more likely they were able to make a full recovery after a brain injury. 40% of those who made a full recovery had been in education for 16+ years, compared to just 10% who had spent less than 12 years in education
• Evaluation of brain plasticity and functional recovery:

  S - evidence to support brain plasticity - Bezzolla

  S - evidence to support brain plasticity - Hubel and Wiesel

  S - evidence to support functional recovery - Danelli et al (E.B)

  S - practical applications - neurorehabilitation
• Research to support brain plasticity (identify);

  • there is research evidence to support brain plasticity and that changes can happen to the brain throughout your life
• Research to support brain plasticity (explain):

  • Bezzolla (2012) found that the brains of participants aged between 40 and 60 years old changed after golf training. Those that were given 40 hours of golf training had more activity in their motor cortex compared to a control group who did not play golf
  • this suggests that if a skill that uses certain neural connections in the brain is carried out a lot, these connections strengthen (increased grey matter)
• Research to support brain plasticity (conclusion):

  • therefore, this adds to the validity of brain plasticity, as it demonstrates that the brain can adapt based on experiences to meet the demands to the individual through a process of synaptic pruning
• Hubel and Wiesel (1963):

  • conducted research on kittens which involved sewing one eye shut to see how the visual cortex would respond
  • they found that the kittens were able to process information from the open eye, but not from the eye that had been sewed shut (even when it was opened back up again)
• Research to support brain plasticity (identify):

  • there is further research to support brain plasticity in animals
• Research to support brain plasticity (explain):

  • Hubel and Wiesel did research on kittens which involved sewing one eye shut to see how the visual cortex would respond. They found that the kittens were able to process information from the open eye
  • this shows that when one functional area of the brain is lost, the other areas can recover this function to compensate for the damage
• Research to support brain plasticity (conclusion):

  • this adds to the validity of brain plasticity and functional recovery, as it demonstrates that another area can carry out this function through a process of neural reorganisation
• Research to support functional recovery (identify):

  • there is research to support functional recovery from the case study of E.B
• Research to support functional recovery (explain):

  • Danelli et al (2013) found that E.B was able to make a full recovery by the age of 15 after having his left hemisphere removed, showing that other areas of his brain compensated for the loss of language centres at the age of 3
• Research to support functional recovery (conclusion):

  • E.B's recovery supports functional recovery because he has been able to recover functions that were lost over time suggesting that the brain is able to adapt to compensate for lost functions
• Practical applications (identify):

  • a strength of research into brain plasticity is that it has practical applications, leading to the development of neurorehabilitation
• Practical applications (explain):

  • although the brain can rewire itself soon after trauma, this slows down after a few weeks, meaning that patients need further support
  • neurorehabilitation is a form of physical therapy on the brain, which is used to help patients recover and improve their functioning
  • for example, they use techniques like the electrical stimulation of the brain to deal with damaged areas. This has had great success in helping the lives of many patients who have suffered brain trauma as a result of an injury or illness
• Practical applications (conclusion):

  • therefore, this adds to the validity of brain plasticity as research has allowed for new and successful techniques to be developed, what has had a positive impact on the lives of both patients who have suffered brain trauma, and their families, by aiding their recovery
  • this also has benefits to the economy