Biopsychology - Plasticity And Functional Recovery Of The Brain Flashcards
What is neural plasticity?
The brain’s ability to change and adapt as a result of experience & learning
What is functional recovery?
The ability of the brain to redistribute certain abilities of the brain that have been lost due to damage/trauma to other parts of the brain
How is the brain able to change through life?
In infancy there is a peak of 15000 synaptic connections in the brain (Gopnick et al), but as we age some are rarely used and are deleted while others are strengthened (synaptic pruning)
It was though that changes in the brain were fixed to childhood but recent research suggests that in any time in life existing neural connections can change throughout life & new ones can be formed (plasicity)
What was Maguire et al’s study of taxi drivers to support plasticity?
Studied the brains of 16 right handed male London taxi drivers who were driving for 1.5+ years-> found more grey matter in the posterior hippocampus than the controls (50 healthy right handed males who didn’t drive taxis) (controls spatial navigation) as taxi drivers must know every street & routes in London
How longer that they were in the job -> more pronounced the difference was)
What was other research done into plasticity by Draganski et al & Mechelli et al?
Draganski et al -> imaged the brains of medical student 3 months before & after final exams -> found changes occurred to posterior hippocampus & the parietal cortex
Mechelli et al -> found a larger parietal cortex in the brains of people who were bilingual compared to monolingual controls
How can functional recovery occur?
Can occur quickly (spontaneous recovery) & then slow down -> may need rehabilitation to further recovery
The brain can:
- recruit homologous areas
- undergo axonal sprouting
- reform blood vessels
How does the brain recruit homogolous areas for functional recovery?
After trauma, the brain can use other pieces of the brain that were doing the same or similar job and use those neural pathways to enable function e.g. using the existing structures of the opposite hemisphere so new pathways dont have to be built
How does the brain undergo axonal sprouting for functional recovery?
After trauma, new nerve endings are grown to join undamaged neurons to create new pathways
How does the brain reform blood vessels for functional recovery?
After trauma, neural pathways are supported and reinforced with blood vessels
STRENGTH: What is the practical application of brain plasticity & functional recovery?
Understanding plasticity has contributed to the neurorehabilitation field -> physical therapy may be required as spontaneous recovery slows down so people may use techniques e.g. movement therapy/electrical stimulation to counter the motor and/or cognitive deficits that may be experienced following a stroke -> shows that the brain has a capacity to ‘fix itself’ to a point but requires further intervention to be successful
WEAKNESS: What are the limitations of brain plasticity & functional recovery regarding negative plasticity?
Brain plasticity can have maladaptive behavioural consequences. For example, 60-80% of amputees have been known to develop phantom limb syndrome which can be unpleasant & painful for the person who has to experience it
STRENGTH: What is a strength of brain plasticity & functional recovery regarding age & plasticity?
Can reduce with age however Benzzola et al demonstrated that 40 hours of golf training produced changes in the neural representation of movement in participants who were 40-60 -> fMRI was able to see reduced motor cortex activity in the novice golfers compared to control group -> shows that neural plasticity occur throughout lifespan
STRENGTH: What is some support from animal studies?
Hubei & Wiesel -> sewed one eye of a kitten shut & analysed the brain’s cortical responses -> found the area of the visual cortex associated with shut eye continued to process information form the open eye
COUNTERPOINT -> CANT GENERALISE TO HUMAN (THEY’RE CATS)
STRENGTH: How does the concept of cognitive reserve support brain plasticity & functional recovery?
Schneider et al -> more time brain injury patients spent in education (taken as indication of cognitive reserve) greater chances of disability free recovery
2/5 patients who achieved DFR had 16 years + in education compared to 10% of patients who had less than 12 in education
