Eye movement effects in MEG

Eye movements are an integral part of human perception, yet in many magneto-encephalography (MEG) and electroencephalography (EEG) studies people try to minimize them, because of the large artifacts they can induce in the signal. Most studies lack a good control check to verify whether eye movements are causing an effect found in the MEG signal. Therefore, it remains unclear how much of an influence eye movements can have on observed effects in MEG. We find that we can decode stimulus location from eye movements in two different stages of a working memory match-to-sample task that encompass different areas of research typically done with MEG. This means that the observed MEG effect might be (partly) due to eye movements instead of any true neural correlate. We suggest how to check for eye movement effects in your data and make suggestions on how to minimize eye movement artifacts from occurring in the first place.