Functional magnetic resonance imaging (fMRI) is based on a measurement of
A)magnetic fields emanating from the surface of the brain.
B)the distribution of dye in the arteries and veins of the brain.
C)virtual lesions following intense magnetic stimulation of the brain.
D)ratios of oxygenated to deoxygenated hemoglobin in the brain.

Question

Quizplus · Accepted Answer

fMRI measures the ratio of oxygenated to deoxygenated hemoglobin in the brain. Areas of the brain that are more active require more oxygen, so they have a higher ratio of oxygenated to deoxygenated hemoglobin. This allows researchers to identify which areas of the brain are being used during certain tasks.

Functional Magnetic Resonance Imaging (FMRI) Is Based on a Measurement