What does fMRI measure in cognitive psychology research?

Functional Magnetic Resonance Imaging (fMRI) is a technique widely used in cognitive psychology to measure brain activity. It does this by detecting changes in blood flow in the brain. When a specific area of the brain is more active, it requires more oxygen, which leads to an increase in blood flow to that area. This relationship between neural activity and blood flow allows researchers to infer which regions of the brain are involved in particular cognitive tasks.

This contrasts with other methods like measuring electrical activity of neurons or direct neural connections. fMRI does not measure the electrical activity of neurons (as in techniques such as EEG), nor does it directly visualize the connections between them. Additionally, while neurotransmitter levels are critical for understanding brain chemistry, fMRI does not measure these levels; instead, it provides insight into where and when various cognitive processes take place as indicated by changes in blood flow.