plasticity and functional recovery Flashcards
What is synaptic pruning?
As we age, rarely used synaptic connections are deleted
Frequently used ones are strengthened
What is plasticity?
Brain’s tendency to change and adapt as a result of experience and new learning
Describe Maguire’s study into plasticity
Studied brains of London taxi drivers - more volume of grey matter in posterior hippocampus
Associated with development of navigational skills
Longer they’d been in the job - more pronounced difference
Describe Draganski’s research into plasticity
Imaged brains of medical students before and after exam
Changes in posterior hippocampus and parietal cortex
Describe Mechelli’s research into plasticity
Larger parietal cortex in brains of bilinguals
What is functional recovery?
Areas of brain adapt after injury, trauma
Healthy brain areas take over functions
What is spontaneous recovery?
Functional recovery which occurs quickly after trauma
Slows down after several weeks
How does functional recovery work?
Brain forms synaptic connections close to area of damage
Unused secondary neural pathways are unmasked
What structural changes occur in the brain during functional recovery?
Axonal sprouting
Reformation of blood vessels
Recruitment of homologous areas
What is axonal sprouting?
Growth of new nerve endings which connect with other undamaged nerve cells
Form new neuronal pathways
What is the recruitment of homologous areas?
On opposite side of brain to area of damage
Evaluation - practical application
Understanding has contributed to neurorehabilitation
Physical therapy needed when spontaneous recovery slows down ie movement therapy
Evaluation - negative plasticity
Maladaptive behaviour consequences
Phantom limb syndrome
Unpleasant sensations due to cortical reorganisation in somatosensory cortex as a result of limb loss
Evaluation - age and plasticity
Functional recovery reduces with age
Bezzola - 40 hours of golf training produced changes in 40-60 year olds
Reduced motor cortex activity - more efficient neural representations
Evaluation - support from animal studies
Hubel and Wiesel - sew one kitten eye shut and analyse brain’s response
Area of visual cortex associated with shut eye continued to process information