Plasticity and Functional Recovery of the Brain After Trauma Flashcards
What is plasticity
the brains tendency to adapt and change functional and physically due to experience and learning
What was Gopnik et al. (1999)
synaptic connections in infant rapidly increase - peaks at around 15,000 by age 2 or 3 - double the amount of connections is an adult brain
What happens to frequently used connections
they are strengthened as we get older
What happens to rarely used connections
they get deleted through the process of synaptic pruning
What was thought about connection changes
that they did not happen in adults, only children - recent studies suggest adult brains don’t remain in fixed state, connections can change and newly form
What was Maguire et al. (2000)
studied London taxi drivers brains - found significantly more grey matter volume in posterior hippocampus - this area links to development of navigational and spatial skills
London taxi drivers take ‘the knowledge’ to test their ability to become a driver
There is a positive correlation between how long taxi drivers are in the job and how pronounced structural difference was
What was Draganski et al. (2006)
saw similar findings to Maguire when looking at brain of medical student 3 months before and 3 months after finals - changes seen in posterior hippocampus and parietal cortex after exam
What was Mechelli et al. (2004)
larger parietal cortex found in brains of bilingual people compared to those who could only speak one language
What if functional recovery of the brain after trauma
a form of plasticity which allows the brain to transfer or redistribute functions usually performed by a damaged area to an undamaged area
What is spontaneous recovery
fast recovery straight after trauma, which then slows down for several weeks or months
Rehabilitative therapy
may be needed for further recovery
What are secondary neural pathways
not typically used
activated or unmasked to enable functioning to continue as it was before - Doidge (2007)
What are the 3 structural changes that take place in the brain
reformation of blood cells, axonal sprouting and recruitment of homologous areas
Axonal sprouting
growth of new nerve endings to connect to other undamaged nerve cells
Recruitment of homologous areas
areas on opposite hemisphere recruited to do specific tasks
Practical application - EVAL
the understanding of processes within plasticity has contributed to the field of neurorehabilitation
spontaneous recovery seems to slow down after a few weeks, so physical therapy is required e.g. movement therapy or electrical stimulation of brain
used to counter deficits in cognitive and motor functioning after a stroke or brain trauma
Negative Plasticity - EVAL
there can be maladaptive behavioural consequences when the brain tries to rewire itself
prolonged drug use may result in poorer cognitive function and greater risk of dementia
60-80% of amputees are said to develop phantom limb disease - continued sensation in missing limb
these sensations are thought to be due to cortical reorganisation in somatosensory cortex
Age and Plasticity - EVAL
the functionality of plasticity tends to diminish with age
brain has greater inclination for reorganisation in childhood due to continuous learning
Bezzola et al. (2012) - demonstrated effect of 40hrs of golf training on neural representation of movement in participants between 40-60yrs old
FMRI used by researchers to observe reduced motor cortex activity in novices compared to those with no training - shows more efficient neural representation came after training - neural plasticity continues throughout life
Taxi Driver - EVAL
Maguire et al. (2000) didn’t study brains before the study - it could be that bigger posterior hippocampus leads people to become taxi drivers or jobs that require similar skills, not that it develops from the learning and new experiences
However, it is shown that more time on the job is positively correlated with bigger posterior hippocampus
