Plasticity and functional recovery of the brain after trauma Flashcards
Brain plasticity
the brain’s tendency to change and adapt (functionally and physically) as a result of experience and new learning
└aka neuroplasticity, cortical remapping
synaptic pruning
└brain experiences rapid growth in synaptic connections during infancy
└peaks at 15,000 at age 2-3 (Gopnik et al, 1999)
└as we age, rarely used connections deleted and frequently used are strengthened (synaptic pruning)
Research into plasticity
list
Eleanor Maguire et al (2000)
Draganski et al (2006)
Mechelli et al (2004)
Research into plasticity
Eleanor Maguire et al (2000)
Eleanor Maguire et al (2000)
└studied the brains of London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than in the matched control group
└part of the brain associated with spatial and navigational skills
└they must take a test called ‘The Knowledge’ to asses recall of city streets and possible routes
└longer they had had the job, the greater the structural difference (positive correlation)
Research into plasticity
Draganski et al (2006)
Draganski et al (2006)
└imaged the brains of medical students three months before and after their final exams
└learning induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex possibly as the result of the exam
Research into plasticity
Mechelli et al (2004)
Mechelli et al (2004)
└found a larger parietal cortex in the brains of people compared to matched monolingual controls
functional recovery
a form of plasticity. Following damage through trauma, the brains ability to redistribute or transfer functions usually performed by damaged areas to undamaged areas
functional recovery
process- time
└the process can occur quickly after trauma (spontaneous recovery) then slow down after weeks or months
└then individuals may require rehabilitative therapy to further their recovery
What happens in the brain during recovery
└the brain is able to rewire and organise itself by forming new synaptic connections close the damaged area
└secondary neural pathways that would not usually be used to carry out certain functions are activated to enable functioning to continue (Doidge, 2007)
Structural changes in the brain
└axonal sprouting: the growth of new nerve endings which connect with other undamaged nerve cells to form new neural pathways
└reformation of blood vessels
└recruitment of homologous areas on the opposite side of the brain to perform specific tasks.
Plasticity and functional recovery of the brain after trauma
limitations
Negative plasticity
└brains ability to rewire itself can have negative behavioural consequences
└Meduna et al (2007)
└prolonged drug use → poorer cognitive function, increased risk of dementia
└Ramachandran and Hiertein (1998)
└60%-80% of amputees develop phantom limb syndrome
└sensations of the missing limb as if it were still there (often painful)
└thought to be due to cortical reorganisation in the somatosensory cortex
Plasticity and functional recovery of the brain after trauma
strengths
Practical application
Age and plasticity -Landina Bezzola et al (2012)
Support from animal studies - Hubel and Wiesel (1963)
Plasticity and functional recovery of the brain after trauma
strengths
Practical application
Practical application
└understanding of the process involved in plasticity has contributed to the field of neurorehabilitation
└after brain damage, spontaneous recovery may slow down after several weeks so physical therapy may be needed to maintain improvements in functioning
└e.g. movement therapy, electrical stimulation of brain to counter deficits in motor and cognitive functioning from a stroke e.g.
└further intervention to completely fix the damage
Plasticity and functional recovery of the brain after trauma
strengths
Age and plasticity
Age and plasticity
└functional plasticity tends to reduce with age
└Landina Bezzola et al (2012)
└showed how 40 hours of gold training produced changes in the neural representation of movement in participants aged 40-60
└using fMRI, researchers observed reduced motor cortex activity in novice golfers compared to the control group
└suggests more efficient neural representations after training
└shows neural plasticity does continue through the lifespan
Plasticity and functional recovery of the brain after trauma
strengths
Support from animal studies
Support from animal studies
└Hubel and Wiesel (1963)
└sewed the eye of a kitten shut and analysed the brain’s cortical responses
└the area of the visual cortex with the shut eye was not idle as predicted but continued to process information from the open eye
