Plasticity and functional recovery from trauma

Question 1

What is “the knowledge” and how does it provide evidence for plasticity?

Answer 1

It is a ‘mental map’ of over 400 prescribed routes around London. Maguire conducted MRI scans on 16 London cabbies. It was found the posterior hippocampus (grey matter) was bigger in London taxi drivers. Suggesting this part of the brain has grown to hold “the knowledge”.

Question 2

Research has shown that neuroplasticity is greatest at what age?

Answer 2

2 - 3 years.

Question 3

Who has conducted research into neuroplasticity?

Answer 3

Eleanor Maguire et al. (2000).
Draganski (2006).
Mechelli (2004).

Question 4

What is plasticity?

Answer 4

The brains tendency to change and adapt (both functionally and physically) as a result of new learning.

Question 5

T / F:

During infancy we have roughly 15,000 synaptic connections which is roughly twice as many as an adult brain.

Answer 5

True.

Question 6

What is synaptic pruning?

Answer 6

As we age we use fewer connections regularly, this leads to them dying off.

Question 7

Describe the study of Maguire (2000):

Answer 7

MRI scans conducted on 16 London cabbies and found enlarged hippocampus / greater grey matter. Found that the longer they had worked as a cabbie, the more pronounced the structural differences.

Question 8

Describe the study of Draganski (2006):

Answer 8

Took images of medical students brains 3 months before and after final exams. The learning had induced changes in the posterior hippocampus and parietal cortex.

Question 9

Describe the study of Mechelli (2004):

Answer 9

Found that bilingual students had a much larger parietal cortex than monolingual students.

Question 10

What is functional recovery?

Answer 10

A form of plasticity which occurs following damage through trauma, it is the brain’s ability to redistribute functions to undamaged areas.

Question 11

How fast is functional recovery from trauma?

Answer 11

The process can occur quickly (spontaneous recovery) and then slow down after several weeks or months to where the individual requires rehabilitative therapy.

Question 12

Name a case study that supports functional recovery from trauma.

Answer 12

Gabby Giffords (US Democratic Politician).

Question 13

What is cortical remapping?

Answer 13

Another word for neuroplasticity:

How the brain can find alternative pathways for doing things when the usual pathways are blocked or destroyed.

Question 14

Give an example of trauma that could cause brain damage:

Answer 14

A stroke or a car accident

Question 15

How does the case study of Gabby Giffords provide evidence for functional recovery from trauma?

Answer 15

In 2011, Gabby Giffords (a former US Democrat) survived an assassination attempt when she was shot in the head from point blank. The bullet went through her left hemisphere and she was put in a waking coma. Within months she made a slight recovery and through rehabilitation she was able to walk and control her left arm and leg. This supports the idea hemispheric lateralisation and the idea of neuroplasticity as other brain areas took over the function of the damaged areas.

Question 16

After spontaneous recovery, what can be done to further recovery?

Answer 16

Using rehabilitative therapy.

Question 17

What does the brain do in order to allow plasticity to occur?

Answer 17

It is able to rewire and reorganise by forming new synaptic connections close to the damaged areas, either creating new pathways or utilising dormant ones.

Question 18

What structural changes may occur to a brain during functional recovert?

Answer 18

• Axonal sprouting.
• Reformation of blood vessels.
• Recruitment of homologous areas.

Question 19

AO3 - Practical applications.

Answer 19

Spontaneous recovery appears to slow after a few weeks so rehabilitation therapy can further recovery. Movement therapy, language therapy and electrical stimulation of the brain can counter cognitive deficiencies following trauma. The brain tends to reach a point of fixing then needs extra support provided by this therapy.

Question 20

What is the Reformation of blood vessels?

Answer 20

Reforming damaged vessels to provide oxygen to the damaged area of the brain.

Question 21

AO3 - Negative plasticity.

Answer 21

Plasticity can be maladaptive, prolonged drug use results in poorer cognitive functioning and increased risk of dementia. 60-80% of amputees develop phantom limb syndrome. The symptoms are unpleasant and painful, it is thought to be due to cortical reorganisation in the somatosensory cortex occurring as a result of limb loss.

Question 22

What is Axonal sprouting?

Answer 22

The growth of new nerve endings which connect with undamaged ones to create new pathways.

Question 23

AO3 - Age and plasticity.

Answer 23

Functional plasticity reduces with age, Bezzola (2012), found 40 hours of golf training produced neural changes in novice participants aged 40-60. fMRI scans showed reduced motor cortex activity compared to the control group, this shows the neural pathways become more efficient after training and demonstrates neural plasticity lasts throughout a lifetime.

Question 24

AO3 - Animal studies.

Answer 24

Hubel and Wiesel (1963) sewed the eye of a kitten shut and analysed cortical responses, the visual cortex for the shut eye continued to process stimuli from the other eye. However, this is completely unethical so could not be repeated again.

Question 25

AO3 - Cognitive reserve.

Answer 25

Educational attainment may influence how well the brain adapts functionally after injury. Schneider et al (2014), more time brain injury patients spent in education (greater cognitive reserve), the greater chances of disability-free recovery. Two-fifths of their patients had more than 16 years’ education compared to the 10% who had less than 12 years. However, there could be other factors such as general health, severity of brain injury, rehab treatment and motivation.

Question 26

AO3 - Enriched environments.

Answer 26

Enriched environments could alter the number of neurons in the brain, Kempermann (1998) investigated rats raised in cages with rats raised in complex environments. The complex group showed greater neuron counts in the hippocampus (associated with memory formation). This shows enriched environments can increase plasticity as there are more neurons.