plasticity

define plasticity

Brain plasticity refers to the brain’s ability to change and adapt both in its function and structure because of experience.

define functional and time line

This is the transfer of functions from a damaged area of the brain after trauma to other undamaged areas.

Neuroscientists suggest that this can happen quickly after trauma (spontaneous recovery) and then slow down after several weeks or months. Therapy may then be needed. During recovery, the brain is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage. Secondary neural pathways that would not typically be used to carry out certain functions are ‘unmasked’ to enable functioning to continue. This process is supported by a number of structural changes.

what are the 3 things that help with functional recovery

1.Axon sprouting: new nerve endings grow and connect with undamaged areas.
2. Reformation of blood vessels.
3. Recruitment of homologous (similar) areas on the opposite hemisphere to do specific tasks e.g. if Broca's area was damaged then an area on the right might take over.

One strength of plasticity is that there is evidence in support

P= There is further research to support the notion of brain plasticity.

E= Maguire et al. (2000) found that the posterior hippocampal volume of London taxi drivers’ brains was positively correlated with their time as a taxi driver and that there were significant differences between the taxi drivers’ brains and those of controls.

E=However, some psychologists suggest that research investigating the plasticity of the brain is limited. For example, Maguire’s 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.

L=Therefore, while Maguire’s research shows that the brain can change in response to frequent exposure to a particular task, some psychologists suggest that holistic approach to understanding complex human behaviour may be more appropriate.

uses of neurorehabiliation

P= A final strength of research examining plasticity and functional recovery is the application of the findings to the field of neurorehabilitation.

E= 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.

L= It demonstrates the positive application of research in this area to help improve the cognitive functions of people suffering from injuries

what an animal study in support

Animal studies also support that functional recovery can occur e.g. Hubel and Wiesel sewed one eye of a kitten shut and analysed the brain’s cortical responses. It was found that the area of the visual cortex that was sewn shut was not idle (as predicted) but continued to process information from the open eye.

the extent to which plasticity can help people recover varies

The extent to which plasticity can occur is related to educational attainment. Schneider et al. (2014) found that patients with the equivalent of a college education are seven times more likely than those who didn’t finish high school to be disability-free one year after a moderate to severe traumatic brain injury. The researchers concluded that ‘cognitive reserve’ (associated with greater educational attainment) could be a factor in neural adaptation during recovery from traumatic brain injury. This means that different people may recover differently after a traumatic accident/illness.

synaptic pruning

This is when synapses become more frequently used they are strengthened and those that are not are lost

case study evidence of plasticy

p= there is case study evidence in support

e= for example danelli et al remove the left hemisphere of EB brain. The left side contains Wernicke and borcas area. He lost all language ability. However over time he developed the ability to speak. When an FMRI was done he found that the right hemisphere was followed the blue print for the left. this shows evidence of plasticity

cognitive reserve

this refer to the brains ability to cope with damage and maintain cognitive function despite age

secondary pathway

In the brain, a secondary neural pathway is a series of neurone connections that begin to take on another function because the normal pathway for that function is damaged

neuronal unmasking

neuronal unmasking refers to a process where "dormant" or previously inactive synapses in the brain become active to compensate for damage or dysfunction in other neural pathways