Plasticity & functional recovery

What is brain plasticity/neuroplasticity?

The brain’s tendency to change & adapt (functionally & physically) as a result of experience & new learning

What is functional recovery?

Following damage by injury or trauma, it is the brain’s ability to re-distribute or transfer functions usually performed by a damaged area(s) to other undamaged area(s)

At what age is the peak number of synaptic connections?

Around 2-3 years old

As we age, what process occurs to delete those connections that are rarely used allowing those connections that are more frequently used to be strengthened?

Synaptic pruning

What experiences have been investigated that actually lead to a change in the brain?

Video games & meditation

What is meant by positive plasticity?

Where our brains develop due to learning & practice from experience

What would be an example of positive plasticity?

Blind people who use braille have enlarged areas of the brain capable of dealing with hand sensory areas

What is negative plasticity?

Changes in the brain involve reduced cognitive abilities

What type of timescale have neuroscientists found for neural plasticity?

It can happen quickly after trauma (spontaneous recovery) & then slow down after several weeks or months

What may be required to support functional recovery?

Therapy

What happens to the brain during recovery?

It is able to re-wire & re-organise itself by forming new synaptic connections close to the damaged area(s)

Secondary neural pathways that would not typically be used to carry out certain functions are ‘unmasked’ to enable functioning to continue which is supported by 3 main structural changes. Name these.

• Axon sprouting

• Re-formation of blood vessels

• Recruitment of homologous areas

What is axon sprouting?

New nerve endings grow & connect with undamaged areas

What is meant by recruitment of homologous areas?

Similar areas on the opposite hemisphere take on specific tasks (e.g. if Broca's area was damaged, then an area on the right might take over)

What does ‘The Knowledge’ test?

Recall of streets & possible routes

What are 2 examples of how knowledge of plasticity be useful in everyday life?

• We can use knowledge to reverse cognitive decline in old people

• We can use it for neurorehabilitation by providing movement therapy or electrical stimulation of the brain after injury in the period between spontaneous recovery & this slowing down

Describe and evaluate evidence of plasticity and functional recovery after trauma in the brain (16 marks)

Write your AO1 paragraph

• Plasticity refers to the brain’s ability to change & adapt (functionally & physically) through experience & learning. The number of synaptic connections peak at around age 2-3, after which synaptic pruning occurs which removes rarely used connections while frequently used ones are strengthened.

• Plasticity can be positive where our brains develop due to learning & practice from experience (e.g. blind people who use braille have enlarged areas of the brain capable of dealing with hand sensory areas). However, it can also be negative, such as prolonged drug use leading to poorer cognitive functioning & old age associated with dementia.

• Functional recovery occurs after physical injury or trauma, where unaffected brain areas adapt to compensate for damaged areas. Recovery may occur spontaneously before slowing down, after which therapy may be needed. During recovery, the brain re-wires & re-organises itself by forming new synaptic connections near the damaged area(s). Secondary neural pathways may become ‘unmasked’ to take over lost functions - structural changes involved include: axon sprouting, re-formation of blood vessels & recruitment of homologous areas.

Describe and evaluate evidence of plasticity and functional recovery after trauma in the brain (16 marks)

Write your strength AO3 PEEL (Hubel & Wiesel)

• Point: One strength of plasticity is there is research evidence in support from animal studies.

• Evidence: For example, Hubel & Wiesel sewed one eye of a kitten shut & analysed the brain’s cortical responses in the visual cortex.

• Explain: Results found the area of the visual cortex linked to the closed eye was not idle as predicted, but instead began processing information from the open eye.

• Link: Therefore, this provides clear experimental evidence for plasticity, increasing the validity of the theory.

Describe and evaluate evidence of plasticity and functional recovery after trauma in the brain (16 marks)

Write your strength AO3 PEEL (Maguire et al.)

• Point: One strength of plasticity is there is research evidence in support of structural changes in the brain due to experience.

• Evidence: For example, Maguire et al. used MRI scans to study London taxi drivers, who had to memorise routes & streets as part of ‘The Knowledge’ test.

• Explain: Results found significantly more grey matter in the posterior hippocampus (linked to spatial & navigational skills) than in a matched control group, as well as a positive correlation between years on the job & grey matter volume.

• Link: Overall, this increases the validity of the theory of plasticity by highlighting that the brain can structurally adapt in response to experience.

Describe and evaluate evidence of plasticity and functional recovery after trauma in the brain (16 marks)

Write your limitation AO3 PEEL (Schneider et al.)

• Point: One limitation of plasticity is that the extent to which it may occur depends on individual differences, such as educational attainment.

• Evidence: For example, Schneider et al. found patients with the equivalent of a college education were 7 times more likely to be disability-free one year after a moderate-to-severe traumatic brain injury compared to those who didn’t finish high school.

• Explain: This suggests that cognitive reserve (the brain’s resilience built through intellectual stimulation) may support more effective neural adaptation during recovery.

• Link: Overall, this means that plasticity is not uniform, meaning recovery outcomes can vary.