Artifact removal using simultaneous current estimation of noise and cortical sources

Abstract

The measurement of magnetoencephalographic (MEG) signals is contaminated by large magnetic artifacts, such as heart beats, eye movements, and muscle activities, and so on. These artifacts can be orders of magnitude larger than the signal from the brain, thus making cortical current estimation extremely difficult. This paper proposes a novel method to remove the effects of artifacts by simultaneously estimating the cortical and artifactual dipole currents. By using proper prior information, we show that this method can estimate the currents of artifacts and cortical activities simultaneously, and the estimated cortical currents are more reasonable in comparison to those of previous methods. © 2009 Springer Berlin Heidelberg.