Magnetoencephalographic response characteristics associated with tongue movement

Whole-head magnetoencephalography (MEG) was employed to study the sources o f activation evoked by both active tongue movement and swallowing in five h ealthy subjects. Evoked magnetic fields were adequately explained in both p aradigms by a time-varying single-dipole model which localized in the tongu e in all subjects. No additional brain sources were detectable. Therefore, MEG detects fields associated with tongue movement that best fit a single-d ipole source in the tongue. Future electrophysiological brain activation st udies where tongue movement is likely should be aware of this observation s ince the tongue behaves like a strong current dipole.