Outline and evaluate functional magnetic resonance imaging (fMRI) as a way of studying the brain.

Question 1

outline

Answer 1

FMRI is a technique used for measuring changes in brain activity while a person performs a task, done by measuring changes in blood flow (indirectly measuring electrical activity of neurons).

When a specific area of the brain is active, more oxygen is used to meet the increased demand, therefore an increase in blood flow is found in the active area.

3D images are produced which shows what specific parts of the brain are involved in certain mental processes.

FMRI scanning has helped develop our understanding of localisation of functioning.

For example, participants asked to alternative between looking at a visual stimulus for 30 seconds and a control state (e.g., 30 seconds with their eyes closed) - fMRI will map which areas of the brain have been activated by the visual stimulus.

Question 2

strength

Answer 2

A strength of using fMRI is that it is non-invasive with low risks as the procedure is painless with very few negative side effects.

This is because the technique uses no radiation as part of the process, unlike CAT and PET scans.

Question 3

strength 2

Answer 3

Furthermore, fMRI scanning has excellent spatial resolution, which refers to its ability to accurately localise function. For example, fMRIs provide very clear and highly accurate images within 1-2mm when identifying changes in brain activity.

Question 4

limit 1

Answer 4

A limitation of using fMRI is that it has poor temporal resolution, which refers to its ability to precisely measure brain activity as it occurs.

This is because there is a 5 second time lag between brain activity occurring and the image being seen, therefore it can be difficult to establish which areas of the brain are responding to certain tasks.

Question 5

limit 2

Answer 5

In addition, fMRI scanning relies fully on patient co-operation as within out this it can be impossible to establish localisation of functioning.

This is because a clear and detailed image can only be captured if the patient lays completely still, the slightest movement can significantly impair the quality of the image.