biopsychology: plasticity and functional recovery of the brain after trauma Flashcards
(24 cards)
What does plasticity describe in the brain?
The brain’s tendency to change and adapt (functionally and physically) as a result of experience and new learning.
Plasticity allows for both the strengthening of frequently used connections and the deletion of rarely used ones.
What significant change occurs in the brain during infancy?
A rapid growth in the number of synaptic connections
what is the approximate number of synaptic connections at around 2-3?
15,000 > this is twice as many as there are in the adult brain
What is synaptic pruning?
The process where rarely used connections are deleted and frequently used connections are strengthened as we age.
Can existing neural connections change or new connections form at any time in life?
Yes, existing neural connections can change or new connections can be formed as a result of learning and experience.
Why are there more synaptic connections during infancy?
Children are constantly taking in new information from the environment/learning.
Does neural plasticity stop after childhood?
No, recent research suggests that plasticity continues throughout life > the brain remains capable of adapting to new experiences
What did Maguire et al study in London taxi drivers?
They found significantly more volume of grey matter in the posterior hippocampus than in a matched control group. > This area of the brain is associated with spatial and navigational skills.
What is ‘the knowledge’ test that London cab drivers must take?
A complex test that assesses their recall of the city streets and possible routes.
Does the study by Maguire et al support plasticity?
Yes, it shows that the experience of learning routes around London has increased the volume of the posterior hippocampus.
This indicates that the brain adapts and grows in response to new learning experiences.
AO3: plasticity is lifelong
One strength is that brain plasticity may be a life-long ability
Bezzola et al demonstrates how 40 hours of golf training produced changes in the neural representation of movement in participants aged 40-60. Using FRMI researchers observed increased motor cortex activity in the golfers compared to the control group.
STRENGTH as this suggest neural plasticity can continue throughout the lifespan
COUNTER: However, there is research to support the idea that in general plasticity reduces with age. Elbert et al. supports the idea that the capacity for neural reorganisation is much greater in children than in adults, meaning that neural regeneration is less effective in older brains. This suggests that older individuals may find learning harder than younger individuals and may go some way in explaining why older individuals find change more demanding than younger people. This supports the idea that plasticity occurs as a result of new learning which is more common in younger people
AO3: negative consequences
There is evidence to suggest that plasticity can have maladaptive behavioural consequences.
Evidence has shown that the brains adaptation to prolonged drug use leads to poorer cognitive functioning in later life, as well as an increased risk of dementia.
WEAKNESS as this suggests the brains ability to adapt to damage is not always beneficial. But it is still adding to the body of evidence which supports the idea that the brain is able to change and adapt in response to experience.
What is functional recovery?
A form of plasticity where the brain redistributes functions from damaged areas to undamaged areas.
What happens to the brain following trauma such as a stroke?
Unaffected areas of the brain adapt and compensate for damaged areas.
What is spontaneous recovery?
A rapid recovery process that occurs shortly after trauma, slowing down after several weeks or months.
What occurs in the brain during recovery?
The brain rewires and reorganizes itself by forming new synaptic connections near the damage.
This process allows for the reestablishment of functions that were lost.
What are secondary neural pathways?
Neural pathways that are typically not used for certain functions but are activated during recovery. > These pathways assist in enabling continued functioning despite damage.
what are the 3 structural changes involved infunctional recovery
- reformation of blood vessels
- recruitment of homologous areas
- axonal sprouting
explain reformation of blood vessels
The brain is able to deal with indirect effects of physical trauma e.g. blood vessels that may have become damaged and are unable to carry oxygen to areas of the brain
explain recruitment of homologous areas
Areas on the opposite side of the brain carry out functions of damaged area
explain axonal sprouting
The growth of new nerve endings which connect with undamaged nerve cells to form new pathways
AO3: individual differences
individual differences (such as level of education) may influence recovery rates
Schneider et al revealed that the **more time people with a brain injury had spent in education the greater their chance of a disability-free recovery **(DFR). 40% of those who achieved DFR had more than 16 years education compared to 10% of those who had less than 12 years education.
WEAKNESS as this suggests that people with brain damage who have insufficient education are less likely to achieve a full recovery. As a result, not everyone benefits from functional recovery equally
AO3: research to support
There is evidence from animal studies to support plasticity and functional recovery of the brain.
Taijiri et al. (2013) found that stem cells provided to rats after brain trauma showed a clear development of neuron-like cells in the area of injury. This demonstrates the ability of the brain to create new connections using neurons manufactured by stem cells
STRENGTH as this further supports the fact that the brain is able to recover from from trauma
COUNTER: human brains are more complex than rat brains so we shouldn’t generalise findings from rats to humans
AO3: real life application
A strength of functional recovery is its real life application
Understanding the processes of plasticity and functional recovery has led to the development of neurorehabilitation. This uses motor therapy and electrical stimulation of the brain to counter the negative effects and deficits in motor and cognitive functions following accidents, injuries and/or strokes. For example constraint-induced movement therapy is used with stroke patients whereby they repeatedly practise using the affected part of their body (such as an arm) while the unaffected arm is restrained.
STRENGTH as this demonstrates the positive application of research in this area to help improve the cognitive functions of people suffering from injuries.
