Biomagnetism Create Inspire

The naturally occurring flow of electric currents in the working brain produces a changing magnetic field, which can be measured outside the head with sensitive SQUID (superconducting quantum interference device) magnetometers. The resulting signals can be analyzed mathematically to yield locations of brain activity as it happens on a millisecond time scale. The estimation of the electric sources on the basis of magnetic field measurements is called magnetic source imaging or MSI. Other terms for the same method include magnetic field tomography and biomagnetic computed tomography. The study of the magnetic fields of the brain is called neuromagnetism and also magnetoencephalography (MEG). The corresponding electrical technique is electroencephalography (EEG).