Plasticity and functional recovery

What is brain plasticity?

Brain plasticity refers to the brain’s ability to change and adapt because of experience

Experience includes everything outside the body e.g. driving a car, playing an instrument and the function and processes of the brain can change as a result of these experiences

Gopnik et al (1999)

Growth in synaptic connections peaks at about 15,000 at age 2-3

What is synaptic pruning?

The removal of rarely used connections and the strengthening of frequently used connections

What is functional recovery?

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

What is neuralunmasking?

The process in which ‘dormant’ synapses open connections to compensate for a nearby damaged area of the brain

What is axonal sprouting?

When undamaged axons grow new nerve endings to reconnect neurons whose links were injured or severed. this allows new connections in the brain to be activated, thus recovering any damage occuring in specific regions

What is neural unmasking supported by?

• axonal sprouting

• reformation of blood cells

• recruitment of homologous areas on the opposite side of the brain to perform specific tasks

  • e.g. if Broca’s area was damaged on the LH, the right sided equivalent would carry out it’s functions. After a period of time, functionality might then shift back to the left side

Maguire et al (2000)

• According to Maguire, the role of the hippocampus is to facilitate spatial memory, in the form of navigation

• Structural MRI scans were obtained

  • 16 right handed male London taxi drivers participated; all had been driving for more than 1.5 years

  • scans of 50 healthy right-handed males who did not drive taxis were included for comparison

Maguire - findings

• increased grey matter was found in the brains of taxi drivers compared with controls. The increased volume was found in the posterior 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.

AO3 - research support

P = there is research support for the idea of brain plasticity

EV = Kuhn et al. found a significant increase in grey matter in various regions of the brain after participants played video games for 30 mins over a two month period. He scanned 62 adult male brains and the MRI results showed these results.

EX = this highlights the idea that the brain has the ability to adapt as a result of a new experience, in this case being video games

EXT = Bezzola et al 2012: demonstrated how 40 hours of golf training produced changes in this neural representation of movement in participants aged 40-60. The researchers used an fMRI and observed that there was reduced motor cortex activity in the novice golfers compared to a control group, suggesting more efficient neural representation after training.

LB = research provides clear evidence for brain plasticity and shows how experience can cause structural changes in the brain which increases the validity of the study

AO3 - maguire support

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

EV = Magire et al. (2000) found that the posterior hippocampal volume of London taxi driver’ 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

C = however, some psychologists suggest that research investigating the plasticity of the brain is limited. e.g. Maguire’s research is biologically reductionist and only examines the size of the hippocampus - a single biological factor - 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

LB = 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.

AO3 - strength - neurorehabilitation

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

EX = following an injury or illness, spontaneous recovery tends to slow down after a number of weeks so forms of physical therapy may be required to improve function of movement

EV = understanding the processes of plasticity and functional recovery had lead to the development of neurorehabilitation which uses motor therapy and electrical stimulation of the brain to counter the negtive effects and deficits in motor and cognitive functions following accidents, injuries and/or strokes

EXT = Furthermore, Taijiri et al. (2013) found that if rats were provided with stem cells following brain trauma, there was a clear development of neuron-like cells in the area of injury. This demonstrates the ability of the brain to create new connections using neurons manufactured by stem cells.

LB = it demonstrates the positive application of research in this area to help improve the cognitive functions of people suffering from brain damage