Brain Plasticity and Functional Recovery Flashcards
What does Brain Plasticity mean
The brain’s ability to change and adapt as a result of experience
What is functional recovery
Moving functions from a damaged area of the brain after trauma to other undamaged areas
How do neural pathways work
Life experience changes they, with those used frequently developing stronger connections and those that are rarely or never used eventually dying
What happens to cognitive functioning with age
There is a natural decline in functioning with age, which can be attributed to changes in the brain
How do humans adapt to changing environments
By developing new connections, and removing weak ones, the brain is able to constantly adapt to changing environments
Why did Boyke study six year olds
Boyke found evidence of brain plasticity in six year olds who were taught juggling, however, when practise stopped these changes were reversed
How were the effects of video games on brain plasiticity tested
They have many complex cognitive and motor demands. Kuhn et al compared a control group with a video game training group who trained for two months for at least 30 mins a day on Super Mario.
What did Kuhn et al find from their video game study
Significant increasing grey matter in various brain areas including the cereberal cortex, hippocampus and cerebellum. This increase was not evident in the control group that did not place Super Mario. Researchers concluded that video game training had resulted in new synaptic connections in brain areas involved spatial navigation, strategic planning, working memory and motor performance
How was the effects of meditation on Brain plasiticity tested
Research by Davidson et al compared 8 practisioners of Tibetan meditation with 10 student volunteers who had no previous meditation experience. Both groups were made to meditate for short periods with sensors attached.
What did Davidson find from their study
The electrodes picked up much greater gamma wave activity in the monks. These are important as they coordinate neuron activity. The students showed only a slight increase in gama wave activity while meditating. Researchers concluded that meditation may not only change the brain in the short term but may cause permianent changes as the monks had four times more gamma wave activity than the control group even before they started meditating
What are the two mechanisms the brain has to recover functionality after trauma
Neuronal Unmasking and Stem cells
What is Neuronal Unmasking
Wall identified ‘dominant synapses’, which are synaptic connections that exist anatomically but their functions are blocked. Under normal conditions neural input is too low for them to be activated, but increasing the rates of input into these synapses, such as following trauma, can open or unmask these dormant synapses. This can open connections to regions of the brain not normally activated, creating a lateral spread of activation which in time gives way to the development of new structures
How can stem cells cause functional recovery
Stem cells are unspecialised cells that have the potential to give rise to different cell types that carry out different functions, including taking on the characteristics of nerve cells. There a 3 views of how stems cells may aid functional recovery (on another slide)
What are the three way that stem cells may aid functional recovery
1 - They could be directly implanted into the brain and directly replace dead or dying cells
2 - Implanted stem cells secrete growth factors that somehow rescue the injured cells
3 -Transplanted cells form a neural network, which links an uninjured brain like, where new stem cells are made, with the damaged region of the brain
How have animal studies supported the presence of brain plasticity
Kempermann et al suggested that an enriched environment could grow the number of neurons in the brain. They found evidence of an increased number of new neurons in the brains of rats housed complex environments compared to rats housed in laboratory cages
Where did Kempermann’s rats show a particular increase in neurons
In the hippocampus, a part of the brain associated with the formation of new memories and the ability to navigate from one location to another.
Who put rats in a maze to grow their brains
Kempermann
How did a study of taxi drivers show evidence of brain plasticity in humans
Maguire et al studied london taxi drivers and discovered that changes in the brain could be detected as a result of extensive experience of spatial navigation.
How was Maguire’s study conducted
They used an MRI scanner to calculate the amount of grey matter in the brains of taxi drivers and a set of control participants.
What were the findings of Maguire’s study
The posterior hippocampi of taxi drivers were significantly larger compared to those of control participants and posterior hippocampal volume was positively correlated to amount of time spent as taxi driver
Who did a study on london cabbies
Maguire
How have animal studies been used to support functional recovery
Tajiri provided evidence of the role of stem cells by having a group of rats with traumatic brain injuries either given transplants of stem cells into the region of the brain affected by traumatic injury, or a solution infused into the brain containing no stem cells. Three months later the brains of stem cell rats showed a clear development of neuron-like cells in the area of injury, as well as a solid stream of stem cells migrating to the injury point. Not in control group
Who decided to give rats traumatic brain injuries to prove that stem cells are important
Tajiri
What has more recent research suggested about adult brain plasticity
It is commonly accepted that functional plasticity reduces with age. With this view the only option following traumatic injury post childhood is to develop behavioural strategies to work around the defecit. However, studies have suggested that even abilities commonly thought to be fixed in childhood can still be modified in adults with intense retraining. Despite this, Ebert et al conclude that the capacity for neural reorganization is much greater in children than adults, as demonstrated by the extended practice that adults require in order to produce changes
Who concluded that adults have poor capacity for neural reorginisation
Ebert et al
