8 - Plasticity and Functional Recovery Flashcards
What does brain plasticity mean?
The brain’s ability to change and adapt as a result of experience.
It allows the brain to cope better with the indirect effects of brain damage, such as swelling or haemorrhage following a road accident, or the damage resulting from inadequate blood supply following a stroke.
How does life experience affect plasticity?
Nerve pathways that are used frequently develop stronger connections, those that are rarely used eventually die.
By developing new connections and reducing weak ones the brain is able to adapt to a changing environment.
However, there is also a decline in cognitive functioning with age attributed to these changes.
When 60 year olds were taught a new skill (juggling), this increased grey matter in the visual cortex.
What can affect brain plasticity?
Life experience
Meditation
Video games
How can meditation affect brain plasticity?
Eight practitioners of Tibetan meditation were compared with ten students who had no previous meditation experience.
Electrical sensors picked up greater gamma wave activity in
the monks, even before they started meditating. Gamma waves coordinate neural activity.
How can video games affect brain plasticity?
Control group compared to a group who had been given video game training for at least 30 minutes a day for two months on the game ‘Super Mario’.
Found playing video games = 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.
What are the advantages of brain plasticity?
Far more new neurons found in the brains of rats in complex environments compared to those in laboratory cages. This increase in neurones was most prominent in the hippocampus, which is involved in the forming of new long-term memories and the ability to navigate.
Grey matter measured in the brains of London taxi drivers using an MRI scan. The hippocampus in taxi drivers was significantly larger than a control group and this was positively correlated with the amount of time they had spent as a taxi driver (the extent of their life experience).
Define functional recovery
A form of plasticity.
Following damage caused by trauma, the brain can redistribute or transfer functions usually performed by damaged areas to other, undamaged areas.
When the brain is still maturing, recovery from trauma is more likely, however, the brain is capable of plasticity and functional recovery at any age. Research has suggested that women recover from a brain injury quicker than men do.
Define neural reorganisation
Transfer of functions from damaged areas of the brain to undamaged ones
Give examples of functional recovery
Neural re-organisation
Neural regeneration
-> axon sprouting
Define neural regeneration
Growth of new neurons and/or connections (axons and dendrites) to compensate for damaged areas
Define axon sprouting
A part of neural regeneration
New nerve endings grow and connect with other undamaged nerve cells to form new neural pathways
When may physical therapy be required? What does it involve?
Spontaneous recovery from a brain injury tends to slow down after a number of weeks so physical therapy 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.
What are the advantages of functional recovery?
Phantom Limb Syndrome can be used as evidence of neural reorganisation. PLS is the continued experience of sensation in a missing limb, as if it were still there. These sensations are often unpleasant and even painful. PLS is thought to be caused by neural reorganisation in the somatosensory cortex that occurs as a result of limb loss.
One eye of a kitten was sewed shut and the brain’s cortical response was analysed. They found that the visual cortex for the shut eye was not idle (as was predicted) it continued to process information from the open eye. This is further evidence that brain areas can reorganise themselves and adapt their function.
What are the disadvantages for functional recovery?
Patients with a college education were found seven times more likely to be disability free a year after a moderate to severe brain injury than those who did not finish secondary school. They concluded that neural reserve could be a factor in recovery from brain injury.
