Plasticty and functional Recovery Of The Brain After Trauma

Question 1

What does brain plasticity mean? what happens during infancy

Answer 1

The brains’ ability to change throughout life.

During infancy, the brain experiences a rapid growth in the number of synaptic connections it has, peaking at about 15,000 per neuron at 2-3 years of age (Gopnik et al, 1999). This is about twice as many as there are in the adult brain.

Question 2

what is synaptic pruning and how does it affect the brain as we age?

Answer 2

• As we age, rarely-used connections are deleted and frequently-used connections are strengthened—a process known as synaptic pruning.
• People once thought that the adult brain was not capable of change but we now understand that synaptic pruning enables lifelong plasticity where new neural connections are formed in response to new demands on the brain.

Question 3

What is “The Knowledge” and how does it relate to Maguire’s findings?

Answer 3

• 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.
• Maguire et al. found that this learning experience alters the structure of the taxi drivers’ brains.
• They also found that the longer the taxi drivers had been in the job, the more pronounced was the structural difference (a positive correlation).

Question 4

What did Eleanor Maguire et al. (2000) find in their study of London taxi drivers? (brain structures)

Answer 4

• Eleanor Maguire et al. (2000) studied the brains of London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than in a matched control group.

This part of the brain is associated with the development of spatial and navigational skills in humans and other animals.

Question 5

What did Draganski et al. (2006) observe about medical students?

Answer 5

• Began Draganski et al. (2006) imaged the brains of medical students three months before and after their final exams.

Learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex presumably as a result of the learning.

Question 6

what happens following physical injury or trauma (functional recovery explanation )

Answer 6

• Following physical injury or other forms of trauma such as the experience of a stroke, unaffected areas of the brain are often able to adapt and compensate for those areas that are damaged.
• The functional recovery that may occur in the brain after trauma is an example of neural plasticity.
• Healthy brain areas may take over the functions of those areas that are damaged, destroyed or even missing.

Question 7

How quickly does functional recovery happen, and what might be needed afterward?

Answer 7

• Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks or months.
• At this point, the individual may require rehabilitative therapy to further their recovery.

Question 8

What structural changes support functional recovery in the brain?

Answer 8

• The brain is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage (a bit like avoiding roadworks by finding a different route).
• Secondary neural pathways that would not typically be used to carry out certain functions are activated or unmasked to enable functioning to continue, often in the same way as before (Doidge, 2007).

Question 9

What are the 3 specific structural changes involved in functional recovery?

Answer 9

• Axonal sprouting: the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
• Denervation supersensitivity: axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. However, it can have the negative consequence of oversensitivity to messages such as pain.
• Recruitment of homologous areas on the opposite side of the brain: specific tasks can still be performed. For example, if Broca’s area was damaged on the left side, the right-sided equivalent would carry out its functions. After a period, functionality may shift back to the left side.

Question 10

AO3: What is one limitation of brain plasticity? (behavioural consequences)

Answer 10

• Point: One limitation of brain plasticity is that it can have negative behavioural consequences.
• Evidence: Research has found that prolonged drug use can lead to poorer cognitive functioning later in life and an increased risk of dementia (Medina et al., 2007). Additionally, Ramachandran and Hirstein (1998) found that 60–80% of amputees experience phantom limb syndrome — painful sensations as if the missing limb were still there.
• Explanation: These effects are thought to be caused by maladaptive plasticity, such as reorganisation in the somatosensory cortex.
• Link: This shows that plasticity is not always beneficial.

Question 11

AO3: What is one strength of brain plasticity? (lifespan)

Answer 11

• Point: A strength of brain plasticity is that it appears to continue across the lifespan.
• Evidence: Bezzola et al. (2012) found that 40 hours of golf training in 40–60-year-olds led to changes in motor cortex activity.
• Explanation: Using fMRI, they observed increased motor cortex activity in the trained group compared to a control group, indicating that older adults can still form new neural representations.
• Link: This demonstrates that the adult brain retains the capacity to adapt, supporting the idea of lifelong plasticity.

Question 12

AO3: What is one strength of research into functional recovery? (PEEL)

Answer 12

• Point: A strength of functional recovery is its real-world application in rehabilitation.
• Evidence: Understanding the brain’s recovery mechanisms has led to developments like constraint-induced movement therapy, where stroke patients are encouraged to use their affected limb while the unaffected one is restrained.
• Explanation: This promotes brain recovery by encouraging damaged areas to regain function.
• Link: Research into plasticity has helped improve clinical rehabilitation strategies.

Question 13

AO3: What is one limitation of functional recovery? (individual differences)

Answer 13

• Point: A limitation of functional recovery is that it may depend on individual differences, such as education level.
• Evidence: Schneider et al. (2014) found that people with brain injuries who had more years of education were more likely to recover without disability.
• Explanation: 40% of those with over 16 years’ education achieved disability-free recovery (DFR), compared to just 10% with under 12 years.
• Link: This suggests recovery outcomes are influenced by cognitive reserve, not just biological processes.