MEG-EEG Primer

Book excerpt: "Neuronal communication in the brain is associated with minute electrical currents that give rise to both electrical potentials on the scalp (measurable by means of electroencephalography [EEG]) and magnetic fields outside the head (measurable by means of magnetoencephalography [MEG]). Both MEG and EEG are noninvasive neurophysiological methods used to study brain dynamics, temporal changes in the activation patterns, and sequences. Their differences between MEG and EEG mainly reflect differences in the spread of electric potentials and magnetic fields generated by the same electric currents in the human brain. In this chapter, we give an overall description of the main principles of MEG and EEG, going deeper into details in the following chapters"--