Plasticity and Functional Recovery

Question 1

What is brain plasticity?

Answer 1

the brains ability to change and adapt functionally and physically as a result of experience of new learning

Question 2

What experience expectant plasticity?

Answer 2

changes in the brain only took place during infancy and childhood

Question 3

What is experience dependent plasticity?

Answer 3

the brain continues to create new neural pathways and alter after existing ones as a result of learning life experiences

Question 4

What is synaptogenesis?

Answer 4

where new synapses are formed.

This can occur throughout life but during infancy there’s an explosion of synaptic formation (known as exuberant synaptogenesis)

Question 5

What is neurogensis?

Answer 5

This refers to when new neurons are grown. In infancy this is responsible for populating the growing brain with neurons, but also occurs in adulthood

Question 6

What is synaptic pruning?

Answer 6

the process of synapse elimination that typically happens between early childhood and the onset of puberty. However this has also been shown to occur to a lesser extent in adulthood

Question 7

What is infancy experience expectant plasticity?

Answer 7

during infancy , the brain experience a rapid growth of numbers of synaptic connections (approx. 15,000 by age of 2/3)

As we age, rarely used connections are deleted and frequently used connections are strengthened in a process called synaptic pruning.

Question 8

What conclusions can be made from infancy experience expectant plasticity?

Answer 8

The brain is ready for responding to experience by altering connections in response to experience

Question 9

What is experience dependent plasticity (taxi drivers)?

Answer 9

Maguire studied brains of taxi drivers (in London) by MRI. He found that more grey matter in posterior hippocampus than in the matched control group.

This part of the brain is associated with the development of spatial and navigational skills. The longer they had been doing the job, the more pronounced the structural difference was.

Question 10

What conclusions can be made relating to plasticity from Maguire’s taxi driver research?

Answer 10

Brain areas change structurally in response to stimulation

Question 11

What is functional recovery?

Answer 11

moving functions from a damaged area of the brain after trauma to other damaged areas

occurs after injuries such as infections and strokes

Question 12

What is neural regeneration (F.R)?

Answer 12

(a.ka. axon sprouting) occurs when new nerve endings grow and connect with undamaged areas

This can compensate for damaged areas and enable the recovery of previously lost functioning. Can be seen as a type of plasticity (synaptogenesis)

Question 13

What is neuronal unmasking (F.R)

Answer 13

occurs when ‘dormant synapses’ in the brain are opened and become functional due to a surrounding brain area becoming damaged

the rate of input to these dormant synapses would increase, opening connections to regions of the brain that are not normally activated and allowing the gradual development of new structures

Question 14

What is neural reorganization?

Answer 14

occurs when the brain transfers functions from the damaged are to undamaged sections of the brain .

i.e. if Broca’s area in the left hemisphere was damaged then an area on the right hemisphere might take over

Question 15

What was Danelli’s case study (2013) about?

Answer 15

investigated a case of an Italian boy (EB) who had most of his left hemisphere removed aged 2.5 to remove a tumor. With intensive therapy, his right hemisphere was able to take over almost all of the functioning that would normally have been done by the left.

this is largely because EB’s brain would have shown maximal plasticity

Question 16

What are 4 factors affecting recover of the brain after trauma?

Answer 16

perseverance
physical exhaustion, stress and alcohol consumption
age
gender

Question 17

What are the strengths of functional recover research (supporting research)?

Answer 17

• there is research to support the idea that the brain can recover from significant trauma
• case study of EB
• implies that functional recovery is possible especially with targeted physio therapy being done

Question 18

What are the strengths of functional recover research (practical applications)?

Answer 18

• useful practical applications
• Newer search into the role of stem cells has revived interest in Neural Transplantation. in theory stem cells implanted in a damaged area have the potential to grow into neurons and make functional synaptic connections that would restore behavioral functions
• this research is in its early days so there is long way to go yet, but is a very exciting avenue to explore

Question 19

What are the weaknesses of functional recover research (validity)?

Answer 19

• research is a case study and therefore lacks population validity.
• case studies involve a small number of P’s
• This means that findings of case studies can be criticized for being unrepresentative and functional recovery cannot be generalized in this case study

Question 20

What are the weaknesses of functional recover research?

Answer 20

• studies such as Boyke (2008) which found even 60 yr olds could regain some abilities thought to be fixed in childhood with intense retraining.
• Elbert et al (2001) concludes that the capacity for neural reorganization is much greater in children than in adults as demonstrated by the extended practice that adults require in order to produce changes
• this suggests that beyond childhood, those suffering from brain trauma may need to develop compensatory strategies to work around the deficit