BIOPSYCHOLOGY - plasticity and functional recovery of the brain after trauma Flashcards
what is plasticity?
the brains tendency to change and adapt as a result of experience and new learning .
involves growth and new connections
what did Gopnik et al (1999) say about the brain?
during infancy, the brain experiences rapid growth in the number of synaptic connections
- there is 2x as many as there are in adult brain
SYNAPTIC PRUNING = as we age= rarely used connections are deleted
- frequently used connections are strengthened
- synaptic pruning allows life long plasticity
outline the procedure + findings of Maguire et al (2000)?
- studied brains of London taxi drivers
- found more volume of grey matter in posterior hippocampus than in a matched control group
- longer the taxi drivers had been in the job, the more different the structure of the brain.
explain Maguire et al’s findings.
posterior hippocampus is involved in the development of the spatial and navigational skills.
- london taxi drivers must know all routes in london for a recall test = this alters the structure of the taxi driver’s brains.
explain Draganski et al.
- imaged brains of medical students = learning induced changes were seen to have occurred to the posterior hippocampus ad the parietal cortex.
what is functional recovery?
- following damage through trauma, the brains ability to redistribute or transfer functions, usually performed by a damaged area to other undamaged areas.
what is spontaneous recovery?
when functional recovery occurs quickly, and then slows down after several weeks or months
what happens in the brain during recovery?
- forms new synaptic connections close to the area of damage.
- secondary neural pathways are ‘unmasked’ to enable functioning to continue.
- axonal sprouting
- denervation supersensitivity
- recruitment of homologous areas on opposite side of the brain
what is axonal sprouting?
growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
what is denervation supersensitivity?
axons that do a similar job become aroused at a higher level to compensate for the ones that are lost.
what are the strengths of research into plasticity?
+ life long ability
Bezzola et al (2012) -40 hours of golf training produced changes in neural representations of movements in ps.
fMRI - showed reduced motor cortex activity in golfers compared to a control group.
shows that neural plasticity can continue throughout the lifespan
+ research suggests there is something called seasonal plasticity. there is evidence that the superchiasmatic nucleus shrinks in animals during spring and expands throughout autumn.
what are the limitations of research into plasticity?
- plasticity may have negative behavioural consequences = evidence = brains adaptation to prolonged drug use leads to poorer cognitive functioning = increasing risk of dementia ( medina et al) = brains ability to adapt to damage is not beneficial.
what are the strengths of functional recovery?
+ RWA = understanding the processes involved in plasticity has contributed to the field of neurorehabilitation. Understanding that axonal growth is possible encourages new therapies to be tried = this increases the value of functional recovery
what are the limitations of functional recovery?
- levels of education may infleunce recovery rates
eg Schneider et al = more time people w/brain injury had spent in education, the greater their chances of disability free recovery. = ppl w brain damage who have insufficient disability free recovery may not achieve a full recovery.