P: As Maguire's study was a quasi-experiment, she couldn't perform random allocation

E: For instance, whether participants were taxi drivers may not have been the only difference between the two groups. Perhaps interacting with people in the taxi could have made them smarter, increasing the size of their hippocampus

E: Thus, as she was unable to control participant variables, there may be extraneous variables which affected the findings of the study as they could have become confounding variables

P: Maguire couldn't establish a cause-and-effect relationship between being a taxi driver and having a large hippocampus

E: For instance, the taxi drivers could have had larger hippocampus' before, which may have led them to become a taxi driver

E: As a result, because Maguire didn't manipulate the independent variable, she couldn't be certain that the cause of the large hippocampus was being a taxi driver, therefore her findings are correlational

P: There is research support

E: Studies of stroke victims who have lost some brain functions due to brain damage have shown that the brain has the ability to re-wire itself with undamaged brain regions taking over the functions of damaged brain regions.

E: Thus, this suggests that neurons can take over at least some of the functions that have been lost, providing evidence to support functional recovery

E: However, the brain can only 'repair' itself up to a specific point

E: As a result, forms of physical therapy may also be required to increase recovery rates and maintain any improvements in functioning.

E: Therefore, perhaps that functional recovery alone can't be relied on to fully re-instate normal function

L: Though, this also shows that the research has practical application as it has been used to improve treatment for people who have suffered trauma to their brain, thus increasing their chances of recovery