Plasticity And Functional Recovery Flashcards
What is brain plasticity?
Refers to the brain’s ability to modify its own structure and function as a result of experience and new learning
What is functional recovery?
Refers to the brain’s ability to change and adapt in order to recover abilities and mental processes that have been compromised as a result of brain injury or disease.
What is synaptic pruning?
With age rarely used synaptic connections in the brain are deleted and frequently used connections strengthened= example of plasticity of brain
What are 3 structural changes the brain undergoes to help it recover after trauma?
- Axonal sprouting
- Reformation of blood vessels
- Recruitment of homologous areas on the opposite hemisphere
State two examples which show support for neural plasticity
Maguire et al. (2000)= London cabbie drivers
Davidson et al. (2004)= Tibetan monks meditating
What is axonal sprouting
New nerve endings grow and connect with other undamaged nerve cells to form new neural pathways.
How does patient J.W. show evidence for functional recovery of the brain?
He developed the capacity to speak out of the right hemisphere with the result that he can now speak about information present to the left or right brain
Describe the study of Maguire et al.
x Cabbie drivers required to learn all city streets and possible routes in London for a test.
x Their brains were scanned using MRI
x Found cabbie drivers had more grey matter in the posterior hippocampus than control group
x This part of the brain is associated with development of spatial and navigational skills
Describe the study of Davidson et al. (2008)
x Compared Tibetan monks with student volunteers with no meditation experience
x Both fitted with electrical sensors during meditation
x Greater activation of gamma waves in monks. This was even true before they started meditating, suggesting the changes are permanent.
2 strengths for plasticity
Research support from humans for neural plasticity:
Maguire et al. (2000)= London cabbies and Davidson et al. (2004)= Tibetan monks
Animal study support
Increased number of new neurones in the hippocampus (navigation) in the brains of rats housed in complex environments rather than lab cages.
2 limitation for plasticity
Negative plasticity:
The brain’s ability to rewire itself can sometimes have maladaptive behavioural consequences.
It was found that prolonged use of marijuana resulted in poorer cognitive functioning as well as an increased risk of dementia later in life.
Plasticity changes with age:
Age is a confounding variable which affects the plasticity of the brain. Functional plasticity tends to reduce with age as the brain has a greater propensity for reorganisation in childhood as it is constantly adapting to new experiences and learning.
COUNTER-ARGUMENT: Researchers showed that 40 hours of golf training in 40-60 year olds produced changes in the neural representation of movement ‡ suggests that neural plasticity is evident in all ages and not just young people.
1 Strength and 1 limitation of functional recovery
Hubel and Wiesel (1963)- sewed one eye of a kitten shut and analysed the brain’s cortical responses. It was found that the area of the visual cortex associated with the shut eye was not idle (as predicted) but continued to process information from the open eye
Level of education may influence functional recovery:
Schneider et al (2000) found that 40% of those who has a recovery has more than 16 years of education versus 10% who had less than 12 years education
