Electrical activity in the brain generates a weak magnetic field in the vicinity of the head. Recording this signal with sensitive detectors is called magnetoencephalography (MEG). The technique may be considered the magnetic counterpart of electroencephalography (EEG), where the signal is recorded from electrodes attached to the scalp. An outstanding feature of MEG (as well as EEG) is that its temporal resolution is virtually unlimited. Thus, MEG is excellently suited for studying brain dynamics. For a magnetic field arising from a single circumscribed brain area, MEG offers high source localization accuracy as well. But this is not the situation in typical experiments. In general, the observed activity is more complex and comprises contributions from several simultaneously active sources. A unique interpretation of the recorded data does not exist under such circumstances, and any conclusion depends on modeling assumptions about the number and configuration of the underlying neuronal sources.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)