Plasticity of the Brain
A01
Brain plasticity refers to the brain's ability to change and adapt as a result of experience.
This ability to change plays an important role in brain development and behaviour.
Researchers used to believe that changes to the brain took place only in infancy and childhood, but more recent research has demonstrated that the brain continues to create new neural pathways and alter existing ones to adapt to new experiences as a result of learning.
The brain also appears to show evidence of functional recovery, moving functions from a damaged area of the brain, after trauma, to an undamaged area.
Increased Brain Stimulation
- As neurons are damaged there is an effect on the neighbouring neurons as they no longer have input.
- This happens with the hemispheres too.
- Although damage may only be on one side, the other hemisphere functions at a lower level too, as it has reduced input.
New vs Old
Old belief
Changes in the brain only occurred during infancy or childhood.
New research
Brain continues to create new neural pathways and alter existing one to adapt to new experiences as a result of learning.
Takatsura et al 2009
They demonstrated that if the undamaged hemisphere is stimulated, recovery from a stroke can be improved.
Life Experience
As people gain new experiences, nerve pathways that are used frequently develop stronger connections whereas those used rarely eventually die.
By developing new connections and pruning away old weaker ones the brain is able to adapt to the changing environment.
There is a natural decline in cognitive functioning with age which can be attributed to the changing brain.
Researches are therefore looking for ways in which new connections can be made in order to reverse this effect.
Boyke et al 2008
- 60 year old taught new skill.
- They found increases in grey matter in the visual cortex, when they stopped practising, these changes were reversed.
Axon Sprouting
When an axon is damaged its connection with neighbouring neurons is lost.
In some cases
Other axons that already connect with that neuron will sprout extra connections to the neuron, replacing the ones that have been destroyed.
It is compensating for the lost neighbour.
This occurs...
Mainly after two weeks after the damage has happened. It helps to replace function, but only if the damaged axon and the compensatory axons do a similar job. If not, problems can occur with function.
Playing Video Games
Video games = complex cognitive and motor demands
Kuhn et al (2014)
Control v video game group (trained for 2 months, at least 30 mins per day on Super Mario)
Found
Significant increase in grey matter in brain areas in video game group but not control
Cortex, hippocampus, cerebellum
Conclusion
Video game training had resulted in new synaptic connections in brain areas involved in skills important in playing the game successfully
spatial navigation, strategic planning, working memory, motor performance
Meditation
Found
E electrodes picked up much greater activation of gamma waves (coordinate neuron activity) in monks
Students only showed slight increase in gamma wave activity whilst meditating
Meditation can change the inner workings of the brain
Davidson et al (2004)
8 practitioners of Tibetan meditation v 10 student volunteers with no previous meditation experience
Both groups fitted with electrical sensors, asked to meditate for short periods of time
Conclusion
Meditation not only changes the workings of the brain in the short-term (increasing efficiency with which information is processed), but may also produce permanent changes (because monks had far more gamma wave activity than the control group before they started meditating)