What is the oldest brain-imaging technique?

A) electroencephalography (EEG)
B) magnetoencephalography (MEG)
C) positron emission tomography (PET)
D) functional magnetic resonance imaging (fMRI)

Electroencephalography (EEG)

A technique for measuring the brain’s electrical activity by placing electrode sensors on the outside of the skull.

Magnetoencephalography (MEG)

A technique for using delicate magnetic sensors on the outside of the skull to detect brain activity.

Positron Emission Tomography (PET)

A technique for creating images of brain activity by injecting a radioactive tracer into the blood and then, using a scanner, finding where in the brain the blood is being metabolized.