Magnetoencephalography (
MEG) is a
functional neuroimaging technique for mapping brain activity by recording
magnetic fields produced by electrical currents occurring naturally in the
brain, using very sensitive
magnetometers. Arrays of
SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, while the
SERF (spin exchange relaxation-free) magnetometer is being investigated for future machines. Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and
neurofeedback. This can be applied in a clinical setting to find locations of abnormalities as well as in an experimental setting to simply measure brain activity.