Neuromagnetism: a new approach for localizing brain function

The physical origins of neuromagnetic signals are described from which it is concluded that magnetoencephalography is potentially much more applicable than electroencephalography for localizing the sources of a variety of neural activities in the brain. The magnitudes of typical neuromagnetic signals are discussed. Selected examples of MEG studies are given. Recent experiments which appear to indicate directly the association of spreading cortical depression with migraine headache are briefly described.