Lesson 8 - Plasticity and Functional Recovery Flashcards
Brain Plasticity
The brain’s ability to change and adapt as a result of experience
Plasticity allows the brain to cope better with the indirect effects of brain damage or the damage resulting from inadequate blood supply following a stroke
Plasticity Research
Life Experiences
Video Games
Meditation
Plasticity Research
Life Experiences
Nerve pathways used frequently develop stronger connections, those rarely used die
By developing new connections and reducing weak ones, the brain is able to adapt to a changing environment
There is also a decline in cognitive functioning with age attributed to these changes
Boyke et al. (2008) taught 60 year olds a new skill (juggling) => increased grey matter in visual cortex
Plasticity Research
Video Games
Kuhn et al. (2014) compared control group to group who had been given video game training for at least 30 minutes a day for 2 months on Super Mario
Found playing video games causes significant increase in grey matter in visual cortex, hippocampus, and cerebellum
Playing video games results in new synaptic connections in brain areas involved in spatial navigation, strategic planning, working memory and motor performance
Plasticity Research
Meditation
Davidson et al. (2004) compared 8 practitioners of Tibetan meditation with 10 students who had no meditation experience
An EEG picked up greater gamma wave activity in monks, even before starting meditating
Gamma waves coordinate neural activity
Plasticity Evaluation Points
Kempermann et al. (1998) - Neurons
Maguire et al. (2000) - Grey Matter
Plasticity Evaluation
Kempermann et al. (1998) - Neurons
Positive
Found far more new neurons in the brains of rats in complex environments compared to those housed in basic cages
Increase in neurons was most prominent in hippocampus
Hippocampus is involved in forming new long term memories and ability to navigate
Plasticity Evaluation
Maguire et al. (2000) - Grey Matter
Positive
Measured grey matter in brains of London taxi drivers using MRI scans
Hippocampus in taxi drivers was significantly larger than control group
Positively correlated with the amount of time they spent as a taxi driver
Functional Recovery
Form of plasticity
Following damage by trauma, brain can redistribute or transfer functions performed by damaged areas
When brain is still maturing, recovery from trauma is more likely (Elbert et al., 2001), however brain is capable of plasticity and functional recovery at all ages
Women recover quicker from brain injuries
Functional Recovery
Neural Reorganisation and Regeneration
Transfer of functions from damaged to undamaged areas of brain => Neural Reorganisation
Growth of new neurons and/or connections (axons/dendrites) to compensate for damaged areas can also occur => Neural Regeneration
Axon sprouting is part of neural regeneration, new nerve endings grow and connect with undamaged nerve cells to form new neural pathways
Functional Recovery
Physiotherapy
Spontaneous recovery slows down after a number of weeks so physiotherapy may be required to maintain improvements in functioning
Techniques can include movement therapy and electrical stimulation of the brain to counter deficits in motor and cognitive functioning that can be experienced following a stroke
Functional Recovery Evaluation Points
Ramachandran and Hirstein (1998) - Phantom Limb Syndrome
Hubel and Torten Wiesel (1963) - Kitten
Functional Recovery Evaluation
Ramachandran and Hirstein (1998) - Phantom Limb Syndrome (PLS)
Positive
PLS can be used as evidence of neural reorganisation
PLS is the continued experience of sensation in a missing limb, as if it was still there
Sensations are often unpleasant and painful
Thought to be caused by neural reorganisation in the somatosensory cortex that occurs as a result of limb loss
Functional Recovery Evaluation
Hubel and Torten Wisel (1963) - Kitten
Swerved one eye of a kitten shut and analysed brain’s cortical response
Found visual cortex for shut eye was not idle and continued to process information from open eye
Further evidence that brain areas can reorganise themselves and apart their functions
