plasticity and functional recovery of the brain

Question 1

what is the definition of plasticity

Answer 1

describes the brain’s ability to change and adapt as we gain new experience, grow and learn new things.

Question 2

what is synaptic pruning

Answer 2

the process that occurs as we age, rarely used connections are deleted and frequently used connections are strengthened

Question 3

what is the ao1 for plasticity

Answer 3

• During infancy the brain experiences a rapid growth in the number of connections it has peaking at approx. 15,000 (neural networks) aged 2-3. → This is twice as many as in an adult brain.
• As we age, rarely used connections are deleted and frequently used connections are strengthened → this process is called synaptic pruning.
• It was originally thought that adult brains had reached a “critical period” after which plasticity ceases.
  However, new research suggests that this is false- and that adult brains are still capable of plasticity.

Question 4

what are the +ve AO3 points for plasticity

Answer 4

• Maguire et al
• medical students
• language abilities

Question 5

expand on the +ve AO3 point for plasticity: Maguire et al

Answer 5

• studied the brains of London taxi drivers in comparison to a control group.
• Scans revealed that the cabbies had a significantly larger amount of grey matter in the posterior hippocampus, and that the longer they had been in the job, the bigger the volume there was in comparison to their colleagues.
• This area of the brain is involved in spatial and navigational skills.
• So the authors concluded that the complex knowledge of routes and systems that the cabbies use every day literally altered the structure of the brain.
• evidence of plasticity in adult brains.

Question 6

expand on the +ve AO3 point for plasticity: medical students

Answer 6

• Further evidence was acquired in a study of brain scans of Medical students three months before and after their final exams.
• Again, changes (increase) in the amount of grey matter in the posterior hippocampus and parietal cortex were significant.
• evidence of plasticity in adult brains.

Question 7

expand on the +ve AO3 point for plasticity: language abilities

Answer 7

• Finally, a study on bilingual vs unilingual (one language) adults showed that the bilingual group had a larger parietal cortex.
• evidence of plasticity in adult brains.

Question 8

what is the definition of functional recovery

Answer 8

describes the brain’s ability to literally remap itself (adapt functionally and physically) following trauma or stroke, so that if a certain brain area is damaged another area can compensate (take over the functioning of) for that area.

Question 9

what is the AO1 for functional recovery

Answer 9

• Functional recovery is one form of plasticity.
• The brain is literally able to rewire itself by forming new synaptic connections close to the area of damage
• Secondary neural pathways that would not usually be used are activated or unmasked to enable functioning to continue.

Question 10

what are the 3 structural brain changes (that allow functional recovery to happen)

Answer 10

1. Axonal Sprouting - the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
2. Reformation of blood vessels
3. Recruitment of homologous (similar) areas on the opposite side of the brain to perform specific tasks. For example if Broca’s area was damaged (left side) the same area on the right could take over its function.

Question 11

what are the +ve AO3 points for functional recovery

Answer 11

• practical application - neurorehabilitation
• cognitive reserve/educational attainment

Question 12

expand on the +ve AO3 point for functional recovery: practical application - neurorehabilitation

Answer 12

• Although neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery); research shows this slows down significantly over the next few weeks and months.
• Next the individual may need rehabilitative therapy to aid in their brain’s functional recovery.
• Techniques may include physical therapy and electrical stimulation of the brain.
• The aim is to counter the deficits which the individual is experiencing in motor/cognitive functioning following the trauma.

Question 13

expand on the +ve AO3 point for functional recovery: cognitive reserve/educational attainment

Answer 13

• There is a body of evidence that suggests that functional recovery is directly correlated with time spent in education.
• Schneider et al (2014) found that the more time brain injury patients had spent in education- an indication of their “cognitive reserve”- the more likely they were to fully recover.

Question 14

what is the -ve AO3 point for functional recovery of the brain

Answer 14

Maladaptive Plasticity:

• There are instances when the plasticity of the brain has negative consequences for individuals.
• One example is amputees who experience phantom limb syndrome because of “plasticity” in the somatosensory cortex
• The pain and discomfort experienced by amputees can be relieved using ‘mirror therapy’ which seems to ‘trick’ the brain into believing the missing limb is present.