plasticity and functional recovery

Question 1

Define plasticity.

Answer 1

the brains tendency to change and adapt as a result of experience and learning.

Question 2

Define functional recovery.

Answer 2

the transfer of functions from a damaged area of the brain after trauma, to other undamaged areas. Functional recovery can take place through a process called neuronal unmasking.

Question 3

Define neural unmasking.

Answer 3

‘dormant’ synapses (which have not received enough input to be active), open connections to compensate for a damaged area of the brain.

Question 4

Define synaptic pruning.

Answer 4

rarely used neural connections are deleted and frequently used ones are strengthened.
corpus callosum - tissue connecting the hemispheres of the brain.

Question 5

Define hippocampus.

Answer 5

part of the limbic system, and plays important roles in the consolidation of info from short-term memory to long-term memory, and in spatial memory that enables navigation.
humans and mammals have 2 hippocampi, one on each side of the brain.

Question 6

Define axonal sprouting.

Answer 6

growth of new nerve endings that connects with other undamaged nerve cells to form new neural pathways.

Question 7

What is meant by the key term reformation of blood vessels?

Answer 7

blood vessels regrow to ensure oxygen and glucose can serve the brain.

Question 8

what is meant by recruitment of homologous areas?

Answer 8

similar areas on opposite sides of the brain take over tasks that the damaged area would have performed.

Question 9

what is meant by cortical reorganisation?

Answer 9

the process by which an existing cortical map is affected by a stimulus resulting in the creation of a ‘new’ cortical map.

Question 10

describe brain plasticity (AO1)

Answer 10

when we say the brain has plasticity or is plastic, it means that it can change and adapt over time.
in infancy, the brain experiences growth in the number of synaptic synaptic connections it has, peaking at around 15,000 at age 2-3 (Gopnick et al, 1999). This is twice as many as in the adult brain.
As we age, rarely used connections are deleted and frequently used connections are strengthened in a process known as synaptic pruning.
It was originally thought that such changes were restricted to the developing brain within childhood, and that the adult brain, having moved beyond a critical period would remain fixed and static in terms of function and structure.
However, research suggests that at any time in life existing neural connections can change, or new neural connections can be formed, as a result of learning or experience.

Question 11

Who conducted a study into the brains of taxi drivers?

Answer 11

Maguire et al (2000).

Question 12

Outline the study of Maguire et al (2000).

Answer 12

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 animals.
As part of training they have to take a complex test which assesses their recall of city streets and possible routes.
it appears that this spatial learning alters the structure of the taxi drivers’ brains.

Question 13

Outline the finding as a result of as correlation by Maguire et al (2000).
Give one limitation of this finding in its support of brain plasiticity.

Answer 13

Found a positive correlation between the size of the posterior hippocampus and the time spent as a taxi driver.
Implies that it is the experience of being a taxi driver that changes the brain, which supports brain plasticity.

However, correlations cannot establish causality, as there may be a third factor affecting the altering of the brain. Therefore its support is limited.

Question 14

Outline functional recovery (AO1).

Answer 14

Following injury or trauma, such as 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 another example of neural plasticity.
Healthy brain areas may take over functions of the brain that are damaged, destroyed or even missing.
Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks, at which point the patient may need rehabilitative therapy.

Question 15

What is meant by spontaneous recovery?

Answer 15

the process of functional recovery occurs quickly after trauma, and then slows down after several weeks or months.

Question 16

What happens to the brain during recovery?

Answer 16

The brain is able to rewire and reorganise itself 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 activated or ‘unmasked’ to enable functioning to continue, often in the same ways as before.

Question 17

The process of what happens to the brain during recovery is supported by a number structural changes.
Name three.

Answer 17

1. axonal sprouting
2. reformation of blood vessels
3. recruitment of homologous areas

Question 18

outline an example of recruitment of homologous areas.
(Broca’s area).

Answer 18

If Broca’s area was damaged (which is on the left side of the brain), the right-sided equivalent would carry out it’s functions.
After a period of time, functionality may shift back to the left side.

Question 19

Name 6 individual differences that may affect recovery after traumatic brain recovery (TBI).

Answer 19

1. the severity of the injury.
2. access and response to treatment.
3. age.
4. level of education.
5. pre-existing environmental, genetic or medical complications.
6. conditions co-occurring with the primary condition.

Question 20

Discuss negative plasticity as a strength of plasticity and functional recovery.

Answer 20

The brains ability to rewire itself can sometimes have maladaptive behavioural consequences.
60-80% of amputees have been known to developed phantom limb syndrome, meaning they continue to experience painful sensations in the missing limb as if it were still there.
these sensations seem to be due to the cortical reorganisation in the somatosensory cortex that occur as a result of limb loss.
such cortical reorganisation is an example of the brains plasticity, thus supporting the notion of brain plasticity.

Question 21

discuss age and plasticity as a limitation of plasticity and functional recovery.

give a counterpoint.

Answer 21

while there is evidence for functional recovery, there is research evidence that this ability can deteriorate with age.
Elbert et al concluded that the capacity for neural reorganisation is much greater in children than in adults, meaning neural reorganisation is less effective in older brains.
therefore we must consider individual differences while assessing the likelihood of functional recovery after trauma.
However, Bezzola et al (2012) found that 40 hours of golf training produced changes in the neural representation of movement in ptps aged 40-60.
Using fMRI, the researcher observed reduced motor cortex activity in the novice golfers compared to a control group, suggesting more efficient neural representations after training.
This shows that neural plasticity does continue throughout the lifespan.

Question 22

Discuss practical application as a strength of plasticity and functional recovery.

Answer 22

understanding the processes involved in plasticity has contributed to the field of neurorehabilitation.
following illness or injury to the brain, spontaneous recovery tends to slow down after a few weeks so physical therapy may be required to maintain improvements in functioning.
techniques may include movement therapy and electrical stimulation of the brain to counter the deficits in motor and/or cognitive functioning following a stroke.