1. Year 2 Bio Psychology Plasticity and functional recovery

2. Starter: Today we’re looking at ‘plasticity’ of the brain…….
Concentrate on the word ‘plasticity’;
What qualities doe you think this word is conveying about the brain?
If the word ‘plasticity’ didn’t exist which words do you think psychologists could use to replace it.
On the basis of your answers to the above which life stages, incidents or events do you think we’ll look at today?

3. Plasticity of the brain (also known as Neuroplasticity) This describes the brains tendency to change and adapt (functionally and physically) as a result of experience and new learning.
During infancy, the brain experience a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 by the age of 2-3 years old. This equates to twice as many as there are in the adult brain. As we age rarely used connections are deleted and frequently used connections are strengthened in a process known as cognitive pruning. This shows that the brain is in a continual state of change from growth in early years to change and refinement in adulthood as we learn and experience.
In recent years, it’s become clear not only that neural organization is changed as a result of experience, but also that there are many different types of experience that can do this. Areas investigated have included video games and meditation.
Plasticity can negative. Examples of this would include: prolonged drug use leading to poorer cognitive functioning and old age being associated with dementia .Both are due to changes in the brain.

4. Plasticity research:
Elanor Maguire et al (2000) studied the brains of London taxi drivers using an MRI and found significantly more grey matter in the posterior hippocampus than in the matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training London Cabbies must take a complex test called ‘the knowledge’, which assesses their recall of the city streets and possible routes. It is also noteworthy that the longer they had been doing the job the more pronounced was the structural difference (a positive correlation).

5. Plasticity research:
Elanor Maguire et al (2000) studied the brains of London taxi drivers using an MRI and found significantly more grey matter in the posterior hippocampus than in the matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training London Cabbies must take a complex test called ‘the knowledge’, which assesses their recall of the city streets and possible routes. It is also noteworthy that the longer they had been doing the job the more pronounced was the structural difference (a positive correlation). What conclusions can we draw? (2 mins to discuss)
Plasticity of the brain
(Also known as Neuroplasticity or cortical remapping ). This describes the brains tendency to change and adapt (functionally and physically) as a result of experience and new learning.
During infancy, the brain experience a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 by the age of 2-3 years old. This equates to twice as many as there are in the adult brain. As we age rarely used connections are deleted and frequently used connections are strengthened in a process known as cognitive pruning. This shows that the brain is in a continual state of change from growth in early years to change and refinement in adulthood as we learn and experience.
In recent years, it’s become clear not only that neural organization is changed as a result of experience, but also that there are many different types of experience that can do this. Areas investigated have included video games and meditation.
Plasticity can negative. Examples of this would include: prolonged drug use leading to poorer cognitive functioning and old age being associated with dementia .Both are due to changes in the brain.

6. Plasticity research:
Elanor Maguire et al (2000) studied the brains of London taxi drivers using an MRI and found significantly more grey matter in the posterior hippocampus than in the matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training London Cabbies must take a complex test called ‘the knowledge’, which assesses their recall of the city streets and possible routes. It is also noteworthy that the longer they had been doing the job the more pronounced was the structural difference (a positive correlation). How does this study suggest Plasticity of the brain? (2 mins to discuss)
Plasticity of the brain
(Also known as Neuroplasticity or cortical remapping ). This describes the brains tendency to change and adapt (functionally and physically) as a result of experience and new learning.
During infancy, the brain experience a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 by the age of 2-3 years old. This equates to twice as many as there are in the adult brain. As we age rarely used connections are deleted and frequently used connections are strengthened in a process known as cognitive pruning. This shows that the brain is in a continual state of change from growth in early years to change and refinement in adulthood as we learn and experience.
In recent years, it’s become clear not only that neural organization is changed as a result of experience, but also that there are many different types of experience that can do this. Areas investigated have included video games and meditation.
Plasticity can negative. Examples of this would include: prolonged drug use leading to poorer cognitive functioning and old age being associated with dementia .Both are due to changes in the brain.

7. strengths weaknesses Plasticity research:
Elanor Maguire et al (2000) studied the brains of London taxi drivers using an MRI and found significantly more grey matter in the posterior hippocampus than in the matched control group. This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. As part of their training London Cabbies must take a complex test called ‘the knowledge’, which assesses their recall of the city streets and possible routes. It is also noteworthy that the longer they had been doing the job the more pronounced was the structural difference (a positive correlation).
Evaluating research into Plasticity of the brain  The conclusion that we drew from this study is that it seems to support the idea that experience changes the brain. As ever, there are strengths of the research that makes it good support for the idea and weaknesses which detract from it’s value as evidence.
Can you spot them?
strengths
weaknesses

8. Evaluation of Mcguire et al
Control group allows us to say that there is a significant difference between taxi drivers and others. (good design).
Use of scientific, objective measurements (MRI)
An attempt to study a real world phenomena.
We can’t be sure that the difference is due to the ‘knowledge’, they weren’t tested before. They could have been taxi drivers because of their already existing difference. (although the positive correlation between experience and structure makes this less likely)

9. Functional recovery
Following physical injury or other forms of trauma such as infection or the experience of a stroke, unaffected areas are sometimes able to adapt or compensate for those areas that are damaged. The functional recovery that occurs in these cases is an example of neural plasticity. Neuro scientists suggest that this can happen quickly after trauma (spontaneous recovery) and then slow down after several weeks or months. Therapy may then be needed.
What happens in the brain during recovery? the brain is able to rewire and reorganise it’s self by forming new synaptic connections close to the area of damage. Secondary neural pathways that would not typically be used to carry out certain functions are ‘unmasked’ to enable functioning to continue. This process is supported by a number of structural changes.
1.Axon sprouting: new nerve endings grow and connect with undamaged areas. 2. Reformation of blood vessels. 3. Recruitment of homologous (similar) areas on the opposite hemisphere to do specific tasks. E.g if Brocas area was damaged then an area on the right might take over

10. It may be possible in the exam that you are asked a 16 marker about either plasticity or functional recovery. If the wording is ‘plasticity’ it may be possible to include information on functional recovery as long as you explain if you recover you are showing plasticity.
If the question only mentions functional recovery you need to be careful that you only talk about those who are recovering and ignore the plasticity associated with normal growth.

11. Research into functional recovery
Tajiri et al (2013) provided evidence for the role of stem cells in recovery from brain injury. They randomly assigned rats with traumatic brain injury to one of 2 groups. One group received transplants of stem cells into the region of the brain affected by traumatic injury. The control group received a solution infused into the brain containing no stem cells. Three months after the brain injury, the brains of stem cell rats showed clear development of neuron-like cells in the area of injury. This was accompanied by a solid stream of stem cells migrating to the brain’s site of injury. This was not the case with the control group.
Where would you put this in your essay and why?

12. Research into functional recovery
Tajiri et al (2013) provided evidence for the role of stem cells in recovery from brain injury. They randomly assigned rats with traumatic brain injury to one of 2 groups. One group received transplants of stem cells into the region of the brain affected by traumatic injury. The control group received a solution infused into the brain containing no stem cells. Three months after the brain injury, the brains of stem cell rats showed clear development of neuron-like cells in the area of injury. This was accompanied by a solid stream of stem cells migrating to the brain’s site of injury. This was not the case with the control group.
Animal study so hard to generalise to humans
Animal studies enable us to monitor the function of the brain before and after trauma because we cause it. Ethically we couldn’t do this in humans and it’s unlikely that we would have measured their function before a natural event (because we didn’t know it was going to happen).
It often makes sense to put an animal study first in your evaluation. You can say that it might not apply to humans and then ……..

13. Further evaluation of functional recovery
….animal study problem!
Human echolocation is a learned ability for humans to sense their environment from echoes. This ability is used by some blind people to navigate their environment and sense their surroundings in detail. Studies in 2010[53] and using functional magnetic resonance imaging techniques have shown that parts of the brain associated with visual processing are adapted for the new skill of echolocation. Studies with blind patients, for example, suggest that the click-echoes heard by these patients were processed by brain regions devoted to vision rather than audition. In human’s evidence is restricted to small scale studies of people who already have issues, it is unclear whether what we are seeing is due to recovery or an individual difference.
Another justification for not ending the essay here….setting you up for the next section

14. ….you’ve just said their may be individual differences!
Further evaluation of functional recovery
….you’ve just said their may be individual differences!
Lets demonstrate that
Age differences in functional recovery It’s a commonly accepted view that functional plasticity reduces with age (Huttenlocher, 2002). According to this view, the only option following traumatic brain injury beyond childhood is to develop compensatory behavioural strategies to work around the deficit (such as seeking social support or to develop strategies to deal with cognitive deficits). However, studies have suggested that even abilities commonly thought to be fixed in childhood can still be modified in adults with intense retraining. Despite these indications of adult plasticity, Elbert et al (2001) conclude that the capacity for neural reorganization is much greater in children than in adults, as demonstrated by the extended practice that adults require in order to produce changes.
Educational attainment and functional recovery: Schneider et al (2014) found that patients with the equivalent of a college education are seven times more likely than those who didn’t finish high school to be disability-free one year after a moderate to severe traumatic brain injury. They carried out a retrospective study based on data from the US Traumatic Brain Injury Systems Database. Of the 769 patients studied, 214 had achieved disability-free recovery (DFR) after one year. Of these, 39.2% of the patients with 16 or more years of education had achieved DFR, as had 30.8% of those with years of education, and just 9.7% of those with less than 12 years of education achieved DFR after just one year. The researchers concluded that ‘cognitive reserve’ (associated with greater educational attainment) could be a factor in neural adaptation during recovery from traumatic brain injury.
concluding paragraph! What does all the evidence tell you?

15. Plenary:
Write a brief concluding paragraph (couple of sentences)……
Some suggestions to help you :
What does the research show you?
Is it possible to recover your functions after a trauma?
Is it certain?
What might it depend up?