Plasticity & Functional Recovery Flashcards
Describe what’s meant by plasticity
The tendency of the brain to change and adapt as a result of experience - the experience results in some connection being lost and some being strengthened
How do synaptic connections vary throughout life?
The brain experiences a massive growth in the number of synaptic connections peaking at roughly 15,000 at age 2-3 yrs (Gopnick et al. 1999)
What is synaptic pruning?
The process by which unused connections are removed and commonly used connections strengthened
When is brain plasticity strongest?
Younger people have brains with the strongest plasticity but changes can occur at any point in life
Outline some research into plasticity
Maquire et al (2000) -Studied london taxi drivers, found more grey matter in their posterior hippocampus this is associated with spatial and navigational skill. Their knowledge altered brain structure – more experienced cabbies had greater differences in brain structure
What is meant by functional recovery?
A form of plasticity. After trauma, the brains ability to redistribute functions usually performed by the damaged area to an undamaged area
What is the concept of functional recovery?
When part of the brain suffers damage of some kind functional recovery enables other healthy areas to compensate and take on extra function – this process is fast to begin with – spontaneous recovery – but slows down eventually until therapy is needed to progress further
What happens to the brain during functional recovery?
New synaptic pathways around the damaged area form. Secondary neural pathways are unmasked to carry out certain functions. Axonal sprouting. Reformation of blood vessels. Recruitment of similar areas on the opposite side of the brain - E.g. Broca’s area damaged on the left side, the equivalent area would be recruited on the right side
What is Axonal Sprouting?
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
How has research into brain plasticity help us in the real world? Use examples in your answers (eval +)
Neurorehabilitation – helps us develop techniques like movement therapy and electrical stimulation to counter the deficits in motor/cognitive functioning that may result from brain damage. The brain can ‘fix itself’ only to an extent, we need to intervene to completely recover
Outline one example of animal research into plasticity and discuss if what we learn from such studies is worth the permanent damage done to the animals (Eval +/-)
Hubel and Wiesel (1963) Cats eye sewn shut. Both visual cortices took over functions for the other eye. Generalizability from cats to humans is an issue. Also, we have no insight into thought or emotions of the animal. Plasticity may be different in animals
Are there downsides to functional recovery? (Eval -)
Negative plasticity - Maladaptive. Drug use leads to poor cognitive function + Cognitive impairment and dementia (Medina et al, 2007)
Phantom limb syndrome (Ramachandran, 1998) comes from reorganization in the somatosensory area
What other factors have been known to affect functional recovery? (Eval +/-)
Level of education (Schneider et al, 2014). The amount of time spent in education (greater cognitive reserve), the greater chance the person has of full functional recovery (DFR). 40% of patients who achieved DFR had been in education 16+ years, 10% of patients who had 12 or less years of education achieved DFR
