Continuous head localization and data correction in MEG

Abstract We describe a system that monitors head movement continuously and corrects the data to remove the effects of motion. Head position is monitored by real-time analysis of signals of three small coils mounted on the subject's head. Data correction is done off-line. Tests of the system with both dipole fitting and SAM beamformer analysis show that it allows correction of errors in source locations due to head movement to ∼ 1 mm.