Biopsychology- plasticity and functional recovery Flashcards
Define brain plasticity (neuroplasticity)
The brains ability to change and adapt because of experience
What are experiences?
Everything outside the body + the functions and processes of the brain can change as a result of these experiences
Why is the brain not a static organ?
Synaptic connections/ neural pathways are continually formed and altered
When does the most growth in synaptic connections occur?
During infancy and early childhood
What happens to rarely used connections during aging?
They are deleted (synaptic pruning) and the more frequently used ones are strengthened
Give two studies that provide evidence for neural connections forming at any time
Boyke- 60 year olds were taught to juggle, they found an increase in grey matter in the visual cortex, although when they stopped practicing the changes were reversed
Kuhn- People trained in a certain video game for 2 months, 30 minutes a day, a significant increase in grey matter was found in areas such as the cortex, hippocampus and cerebellum. It also resulted in new synaptic connections involved in spatial navigation, and strategic planning
What was the role of the hippocampus according to Maguire?
To facilitate spatial memory in the form of navigation
What was the aim of Maguire’s study?
To examine whether structural changes could be detected in the brains of people with extensive experience of spatial navigation
What was the method of Maguire’s study?
-Structural MRI scans were obtained
-16 right handed male London taxi drivers participated all had been driving for more than a year and a half
-Scans of 5o healthy right handed males who did not drive taxis were included for comparison (control groups)
What were the results of Maguire’s study?
-Increased grey matter was found in the brains of taxi drivers compared with controls in two brain regions, the right and left hippocampi- the increased volume was found in the posterior (rear) hippocampus
-Changes with navigation experience- a correlation was found between the amount of time spent as a taxi driver and volume in the right posterior hippocampus
What did Maguire’s study conclude?
Evidence for the idea of brain plasticity- experience can change the structure of the brain (enlarged hippocampus)
Define functional recovery
The transfer of functions from a damaged area of the brain after trauma to other undamaged areas
Give an example of functional recovery
-Jody Miller
-3 year olds
-Rasmussen encephalitis in right hemisphere
-Had a hemishpherectimy (on right side)
-Lives a relatively normal life apart from slight prarlysis on left side of body
-Her left hemisphere compensates
Does spontaneous recovery occur quickly ? What happens after?
-Yes
-Recovery can slow down and the person may require rehabilitative therapy
What is neuronal unmasking?
Dormant synapses (which have not received enough input to be active) open connections or compensate for nearby damaged areas of the brain
What is the function of stem cells?
-Unspecialised cells that can become specialised for different functions
-Can provide treatments for brain damage by replacing dead/dying cells
Define structural plasticity
changes within brain structures
Give an evaluation point (Kuhn et al research)
-There is research support for the idea of brain plasticity
-Kuhn et al found a significant increase in grey matter in various regions of the brain after participants played video games for 30 minutes over a 2 months period
-This matters because Kuhn provides clear evidence for brain plasticity and shows how experience (playing computer games) can cause structural changes in the brain
Give an evaluation point (Maguire et al)
-Further research to support the notion of brain plasticity
-Found that the posterior hippocampal volume of London taxi drivers brains were positively correlated with their time as a taxi driver
-There were significant differences between the taxi drivers brain and those controls
-Some psychologists suggest that research investigating the plasticity of the brain is limited
-Maguires research is biologically reductionist and only examines a single biological factor (the size of the hippocampus) in relation to spatial memory
-This approach is limited and fails to take into account all of the different biological/cognitive processes involved in spatial navigation which may limit our understanding
-This shows that the brain can permanently change in response to frequent exposure to a particular task
Give an evaluation point (neurorehabilitation)
-A final strength of research examining plasticity and functional recovery is the application of the findings to the field of neurorehabilitation
-Understanding the processes of plasticity and functional recovery had led to the development of neurorehabilitation which uses motor therapy and electrical stimulation of the brain to counter the negative effects and deficits in motor and cognitive functions following accidents, injuries and or strokes
-This demonstrates the positive application of research to this area to help improve the cognitive functions of people suffering from injuries
Give an evaluation point (Evidence is not consistent)
Neuroplasticity and functional recovery do not always happen when needed- evidence is not consistent
-The case of HM who had his hippocampus removed at the age of 27, he suffered from catosphrophic anterograde amnesia after having corrective surgery for epilepsy
-However this does not acknowledge individual differences because of the case of Jody Miller
-This casts doubt as the universality of plasticity does not apply in every case
