Plasticity and functional recovery of the brain Flashcards
Definition of brain plasticity
The brain’s ability to change and adapt as the result of experience. These changes occur post-infancy/adolescence, suggesting that adult brains will alter in response to different experiences, for example by creating new neuronal pathways
What is grey matter
Neurons and synapses
Examples of plasticity - juggling
As people gain new experiences, nerve pathways that are used more frequently develop stronger connections, whereas neurons that are rarely or never used eventually die
However, there is a natural decline in cognitive functioning as people age but researchers have found that training can help to reverse these effects
E.g. 93 healthy elderly volunteers (mean age 60) taught a new skill - juggling. 24 of these participants didn’t complete the study. Found that grey matter in the visual cortex of participants increased. However, once the training stopped, these changes were reversed
Examples of plasticity - super mario bros
Participants asked to play Super Mario 64 for at least 30 minutes per day for 2 months
After this training, MRI scans were used and they found a significant increase in grey matter in brain areas such as the prefrontal cortex, hippocampus and cerebellum
Concluded that some video games can improve spatial navigation, strategic planning and working memory
Low control - the participants could have been gamers and therefore have been playing for a lot more than 30 mins a day
Brain plasticity AO3 - meditation
Studied a group of 8 Tibetan monks and a control group of 10 students who had no experience of meditation
Found that when both groups were asked to meditate, the monks showed much greater activation of gamma brain waves (which are involved in perception and consciousness and play a key role in nerve cell communication) than the students
Suggests that meditation can alter how the brain works
However, meditation takes skill and so is difficult to apply to everyone
Brain plasticity AO3 - taxi drivers
The brain structures of 16 male London taxi drivers were studied to see whether their experience of spatial navigation had changed their brain
Through brain scanning using MRIs, the researchers discovered that the posterior hippocampus of taxi drivers were significantly larger than those of a control group
Furthermore, the more experienced they were, the larger their hippocampus volume was
Reliable as brain scans were used
Functional recovery after trauma
Researchers have found that stroke victims can regain brain functioning as their brain re-wires itself to compensate for damaged areas. Known as functional recovery
If one brain area is damaged, other parts will take over the lost functions
This is the result of the plasticity of the brain, which allows functional and structural changes after trauma
Neuronal unmasking
‘Dormant synapses’ identified in the brain which exist but whose function is blocked
Before brain trauma, these synaptic connections have little neural input so are ineffective
However, post-trauma the brain may increase neural input into these sections to compensate for damage to an adjacent brain area. This has the effect of ‘unmasking’ the dormant synapse. This can lead to new connections between different regions of the brain, and eventually structural change and functional recovery
Stem cells
These are unspecialised cells which have the potential to become any cell type, such as taking on the characteristics of a nerve cell
Researchers believe that by implanting stem cells into the brain, they can replace cells damaged by trauma
Alternatively, these stem cells may form a new neural network, which can link an uninjured brain site with the damaged region of the brain
Functional recovery AO3 - research support for stem cells
Rats with traumatic brain injury given transplants of stem cells
Three months after the injury, the brains of these rats showed development of neuron-like cells in the injured area, and a stream of stem cells moving towards the site of the injury
These changes were not present in a control group, suggesting that stem cells can lead to functional recovery following trauma
Functional recovery AO3 - age differences in functional recovery
Most researchers agree that functional plasticity reduces with age
For example, it was concluded that the neural reorganisation was much better in children than adults
However, with extensive retraining, adults have been able to modify their brain structures to produce functional recovery
Functional recovery AO3 - educational attainment and functional recovery
Was found that more educated patients were more likely to recover from brain trauma than less educated patients
In particular, patients with a college education (or equivalent) were seven times more likely to recover one year after a moderate to severe brain injury than those who did not finish high school.
In a study of 769 patients, 39% of patients who had attended 16 or more years of education had recovered, compared with 9% of those with less than 12 years of education
The researchers interpreted this as showing that ‘cognitive reserve’ (indicated by educational attainment) could also play a role in functional recovery
