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Plasticity and Functional Recovery - Coggle Diagram
Plasticity and Functional Recovery
Functional Recovery
A form of plasticity. following damage through trauma, the brain's ability to redistribute or transfer functions usually performed by a damaged area to undamaged areas.
Danelli et al - Aim:
to investigate if the brain can functionally recover after trauma by redistributing functions normally performed by the damaged area to other undamaged areas.
Method:
operated on at the age of 2 1/2 to remove a large tumour from his left hemisphere. Due to the size of the tumour nearly the entire left hemisphere was removed and at the time, all his linguistic abilities disappeared too. He underwent a large rehab programme to improve his language skills
Results
: Language abilities improved at the age of 5 and when tested again at 17 to compare him to normal people they found his right hemisphere has compensated for the loss of the left hemisphere and that he was functioning linguistically well. Some parts weren't to the expected standard.
Conclusion:
They concluded that hemispheric lateralisation can be compensated for to at least a basic degree by the non-specialist hemisphere.
(-) Case study:
we cannot be certain that EB represents the population and that the functional brain recovery demonstrated by EB would occur in other human beings.
(+) Practical Application:
Following the illness of injury to the brain spontaneous recovery tends to slow down after a number of weeks so forms of physical therapy - such as electrical stimulation of the brain - may be required in order to maintain improvements in functioning.
(-) The concept of cognitive reverse:
Schneider discovered that the more time brain injury patients had spent in education - what was taken as an indication of their cognitive reserve - the greater their chances of disability-free recovery.
Functional recovery and age:
studies have suggested that even abilities commonly thought to be fixed in childhood can still be modified in adults with intense training.
Plasticity
Plasticity refers to the brain's tendency to change or adapt as a result of experience and new learning. This generally involved the growth of new connections.
Maguire et al: Aim:
To investigate whether changes in the brain could be detected as a result of extensive experience of spatial navigation.
Method:
16 male London taxi drivers and 50 males who do not drive taxis - control group. Using an MRI scanner, the researchers calculated the amount of grey matter in the brains of taxi drivers and a set of control participants.
Results:
The posterior hippocampus of taxi drivers was significantly larger relative to those of control participants. This part of the brain is associated with spatial and navigational skills in humans and animals. The volume was positively correlated with the amount of time they had spent as a taxi-driver.
Conclusion:
The brain changes physically as a result of experience
(-) Population validity:
the sample of 16 male London taxi drivers is small and therefore may not be representative of the whole population
(-) Correlation:
her study does not demonstrate that the taxi drivers experience directly caused the changed in their brain
(+) Age and Plasticity:
Plasticity reduces with age. Ladina Bezzola demonstrated how 40 hours of golf training produced changes in the neural representations of movement in participants aged 40-60. using fMRI, researchers observed increased motor cortex activity in the novice golfers compared to control group.
(-) Negative plasticity:
60-80% of amputees have been known develop phantom limb syndrome - continued experience of sensation in the missing limb were still there. Sensations are usually unpleasant, painful and thought to be due to cortical reorganisation in the somatosensory cortex.
Axonal Sprouting:
the growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
Denervation Supersensitivity:
this occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. However, it can cause a lot of pain.
Recruitment of homologous areas:
on opposite side of the brain. This means that specific tasks can still be performed. e.g., if Broca's area was damaged.