plasticity and functional recovery Flashcards
what is the plasticity of the brain
this describes the brain’s tendency to change and adapt as a result of experience and new learning
This generally involves the growth of new connections
what happens to the brain during infancy
during infancy, the brain experiences a rapid growth in the number of synaptic connections it has peaking at approximately 15,000 at age 2 - 3 years
this is twice as many synaptic connections than the adult brain as we
why do the number of synapses decrease as we age
as we age, rarely used connections are deleted and frequency used connection are strengthened
this process is known as synaptic pruning
what was the plasticity of the brain originally thought to be restricted to
originally it was thought that such changes were restricted to the developing brian within childhood and that the adult brain has moved beyond a critical period, would remain fixed and structure
however, more recent research suggests that at any time in life existing neural connections can change or new neural connections can be formed as a result of learning and experience
who did research into plasticity
Eleanor Maguire (2000) studied the brains of London taxi drivers and found significantly more volume of grey matter in the posterior hippocampus than n a matched control group
what is the grey matter in the posterior hippocampus
part of the brain associated with the development of spatial and navigational skills on humans and other animals
what were the results of the study performed as Eleanor Maguire
as part of training, the London cabbies must take a complex test called the knowledge which assesses their:
- recall of the city streets
- possible routes
The results of this learning experience are to alter the structure of the taxi drivers’ brian
Also, the longer they had been in the job the more pronounced was the structural difference ( this is a positive correlation)
what study also produced a similar finding
a similar finding was observed by Dragnski et al (2006)
they imaged brains of med students
3 months before and after their final exams
learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex presumably as a result of the exam
what happens to the brain after it experiences trauma
following physical injury or other forms such as the experiences of a strike, unaffected areas of the brain are to adapt and compensate for those areas that are damaged
the functional recovery that may occur in the brain after trauma is another example of neural plasticity
- healthy brain areas may take over the functions of these areas that damaged, destroyed, or even missing
what do neuroscientists suggest happen to the brain after trauma
neuroscientists suggest that this process ( the one where the brian arranges itself) can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks or months
what happens in the brain during recovery
the brain is able to rewrite and reorganise itself by forming new synaptic connections close to the area of damage
(a bit like avoiding roadworks on the way to school by finding a different route)
secondary neural pathways that would not typically be used to carry out certain functions are activated or unmasked to enable the functioning to continue often in the same way as before (Doidge 2007)
This process is supported by a number of structural changes in the brain
what are the structural changes in the brain during the recovery
axon sprouting
reformation of blood vessels
recruitment of homologous of similar areas on the opposite side of the brain to perform specific tasks e.g. if Broco’s area was damaged on the left side of the brain, the right-sided equivalent would carry out its functions.
After a period of time functionality may then shift back to the left side
