Plasticity & Functional Recovery of Brain

Question 1

what is plasticity

Answer 1

brains ability to change/adapt because of experience = create new/adapt neural pathways
e.g. driving car, playing instrument

Question 2

synaptic pruning

Answer 2

rarely used connections get deleted, and frequently used are strengthened

Question 3

when are changes to the brain most likely to occur

Answer 3

during adulthood and childhood, mostly within childhood – peaking at 3yrs (15k neurons, approx. 2x as many as in human brain)

Question 4

outline Maguire et al’s plasticity research (2000)

Answer 4

• studied brain of London taxi drivers = had taken ‘The Knowledge’
• found greater volume of grey matter in posterior hippocampus compared to control group
• longer time in job = more pronounced structural diff

Question 5

what does Maguire’s research show about brain plasticity

Answer 5

• shows learning experience alters brain structure
• looks as if, when extra demands put on brain = it can “borrow” cells from less-used areas to “build up” much-needed areas
• suggest posterior hippocampus role in spatial navigation

Question 6

what is functional recovery (after trauma)

Answer 6

transfer of functions from a damaged area of the brain after trauma to other undamaged area

Question 7

what happens to the brain during recovery

Answer 7

• Doidge
  = brain reorganises itself
  = mitigate new synaptic connections close to area of damage, take over function of damaged area
• neuronal unmasking = formation of secondary neural pathways, activate previously ‘dormant’ neurons
  = enable functioning to continue

Question 8

what structural changes support process of functional recovery

Answer 8

1. axonal sprouting
   = new nerve endings grow, connect with other undamaged nerve cells to form new neuronal pathways
2. denervation supersensitivity
   = axons doing similar job are aroused to higher level, compensate for lost ones
3. recruitment of homologous structures
   = on opp. side of brain
   e.g., if B’s Area damaged, right-side equivalent would carry out its function

Question 9

pro of plasticity and functional recovery

Answer 9

IRL application
- Understanding processes of plasticity and functional recovery led to development of neurorehabilitation
= uses motor therapy/electrical stimulation of brain
= counter negative effects/deficits in motor/cognitive functions from accidents, injuries and/or strokes.

= demonstrates positive application of research = help improve cognitive functions of people suffering from injuries

Question 10

pros of research into plasticity

Answer 10

FURTHER RESEARCH SUPPORT
Kuhn
= playing video games for 30+ minutes per day resulted in increased brain matter in the cortex, hippocampus, and cerebellum

= complex cognitive demands of mastering video games caused formation of new synaptic connections in brain sites that control spatial navigation, planning, decision-making, etc.

Question 11

cons of research into plasticity

Answer 11

LOW GENERALISABILITY
- London taxi drivers used = all male, 16 of them
Gives no info on brain plasticity in females = unrepresentative

NEGATIVE PLASTICITY
= research assumes plasticity always positive
- Medina et al = brain adapting to prolonged drug use leads to poorer cognitive functioning in later life, + increased dementia risk
- 60-80% amputees = phantom limb syndrome = unpleasant/painful sensations thought to be caused by cortical reorganisation of somatosensory area due to limb loss

= brain’s ability to adapt to damage not always beneficial

Question 12

cons of research into functional recovery

Answer 12

LOW GENERALIASABILITY
- tend to use small sample sizes = low population validity
= making it difficult to draw conclusions