Brain Localization and Neuroplasticity

Question 1

What is Localization of a function?

Answer 1

Localization of function is the theory that specific parts of the brain are responsible for specific behaviours or cognitive processes.

Although we know that some parts of the brain do play specific roles in behaviour, rarely does a part of the brain work in complete isolation.

Question 2

Studies for Localization

Answer 2

Maguire Study

Question 3

Aim of Maguire Study

Answer 3

Aim: The aim of the study was to see whether the brains of London taxi drivers would be somehow different as a result of their exceptional knowledge of the city and the many hours that they spend behind the wheel navigating the streets of London.

Question 4

Procedure of Maguire Study

Answer 4

Procedure: The participants for this study were 16 right-handed male London taxi drivers. The taxi drivers were compared with the MRI scans of 50 right-handed males who did not drive taxis. In order to take part in the study, the participants had to have completed the “Knowledge” test and have their license for at least 1.5 years. The controls were taken from an MRI database. The sample included a range of ages so that age would not be a confounding variable.
The study is correlational in nature as the IV is not manipulated by the researcher. The researchers were looking to see if there was a relationship between the number of years of driving a taxi and the anatomy of one’s brain. It was also a single-blind study - that is, the researcher did not know whether she was looking at the scan of a taxi driver or a control.
The data from the MRI was measured using two different techniques: voxel-based morphometry (VBM) and pixel counting. Voxel-based morphology (VBM) was used in this study to measure the density of grey matter in the brain. Pixel counting consists of counting the pixels in the images provided by the MRI scans in order to calculate the area of the hippocampus.

Question 5

Findings of Maguire Study

Answer 5

Findings: there were two key findings of the study. First, pixel counting revealed that the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and the anterior hippocampi were significantly smaller. VBM showed that the volume of the right posterior hippocampi correlated with the amount of time spent as a taxi driver. No differences were observed in other parts of the brain.

Question 6

Conclusion of Maguire Study

Answer 6

Conclusion: Maguire argues that this demonstrates that the hippocampus may change in response to environmental demands.
How does this relate to localization of function? It appears that the posterior hippocampus is involved when previously learned spatial information is used, whereas the anterior hippocampal region may be more involved during the encoding of new environmental layouts.

Question 7

What is Neuroplasticity?

Answer 7

Changes that occur in the brain after breaking and forming synaptic connections between neurons
Can be affected by genetic reasons or environmental reasons (e.g. learning or injury)
Synaptic plasticity depends on neuron activity. The more active, the better they are at connecting with other neutrons

Question 8

Study for Neuroplasticity

Answer 8

Maguire
Draganski (2004)
Mercenich and collagues (1984)