Plasticity And Functional Recovery

Question 1

What is meant by plasticity?

Answer 1

The idea that the brain has the ability to change as a result of life experiences and new learning.

Question 2

What is synaptic pruning?

Answer 2

• frequently used neural pathways become stronger
• neural pathways which aren’t used become weaker and are eventually lost

Question 3

:) London Taxi Drivers

Answer 3

Maguire et al (2000)
- using an MRI scanner, calculated the amount of grey matter in 16 taxi driver brains to a control group of 50 non-taxi drivers
- the posterior hippocampi of taxi drivers were significantly larger than that of the control group
- positive correlation between size of posterior hippocampi and time spent as a taxi driver

Question 4

:) Video game research

Answer 4

Kühn et al (2014):
- compared a control group with a video game training group who trained at least 30min a day for two months
- significant increase in grey matter in different brain areas such as the cortex, cerebellum, and hippocampus

Question 5

:( Negative impacts

Answer 5

Medina et al (2007): brain adaptation to prolonged drug use leads to poorer cognitive function in later life as well as increased risk of dementia

Ramachandran et al (1998): 60-80% of amputees struggle with phantom limb syndrome which is thought to to be due to cortical reorganisation in the somatosensory cortex

Question 6

What is meant by functional recovery?

Answer 6

Neural reorganisation, a type of plasticity where functions performed by areas of the brain are lost or damaged are performed by undamaged areas of the brain

Question 7

Axonal sprouting

Answer 7

The growth of new nerve endings which connect to other undamaged nerve cells to form new neuronal pathways

Question 8

Neuronal unmasking

Answer 8

The brain rewires itself by forming new synaptic connections
- Wall (1971): increased input into the dormant synapses “unmasks” them allowing for connections to be made

Question 9

Denervation super-sensitivity

Answer 9

Axons that do a similar job become aroused to a higher level to compensate for the ones that are lost

Question 10

Recruitment of homologous areas

Answer 10

If one area is damaged on one side of the brain, the opposite side equivalent would carry out it’s functions

Question 11

:) Case Study support

Answer 11

Danielli (2013): 14y/o EB
- at the age of two and a half, EB had a hemisphereoctomy, on the left hemisphere due to a tumour
- couldn’t speak until two years later
- right hemisphere followed a “left-hemisphere blueprint” for language from fMRI scans

Question 12

:) Neurorehabilitation

Answer 12

Understanding axonal sprouting has led to therapies such as neurorehabilitation and constraint induced movement therapy to strengthen motor connections for the affected side of their body

Question 13

:( Age differences in functional recovery

Answer 13

Elbert et al (2001): capacity for neural reorganisation is much greater in children than in adults
- even abilities commonly thought to be fixed in childhood can still be modified in adults with intense training