Source connectivity analysis with MEG and EEG
Article first published online: 23 FEB 2009
Copyright © 2009 Wiley-Liss, Inc.
Human Brain Mapping
Special Issue: Electromagnetic Brain Imaging
Volume 30, Issue 6, pages 1857–1865, June 2009
How to Cite
Schoffelen, J.-M. and Gross, J. (2009), Source connectivity analysis with MEG and EEG. Hum. Brain Mapp., 30: 1857–1865. doi: 10.1002/hbm.20745
- Issue published online: 11 MAY 2009
- Article first published online: 23 FEB 2009
- Manuscript Accepted: 14 JAN 2009
- Manuscript Received: 21 NOV 2008
- MEG, magnetoencephalography;
- EEG, electroencephalography;
- source localization
Interactions between functionally specialized brain regions are crucial for normal brain function. Magnetoencephalography (MEG) and electroencephalography (EEG) are techniques suited to capture these interactions, because they provide whole head measurements of brain activity in the millisecond range. More than one sensor picks up the activity of an underlying source. This field spread severely limits the utility of connectivity measures computed directly between sensor recordings. Consequentially, neuronal interactions should be studied on the level of the reconstructed sources. This article reviews several methods that have been applied to investigate interactions between brain regions in source space. We will mainly focus on the different measures used to quantify connectivity, and on the different strategies adopted to identify regions of interest. Despite various successful accounts of MEG and EEG source connectivity, caution with respect to the interpretation of the results is still warranted. This is due to the fact that effects of field spread can never be completely abolished in source space. However, in this very exciting and developing field of research this cautionary note should not discourage researchers from further investigation into the connectivity between neuronal sources. Hum Brain Mapp 2009. © 2009 Wiley-Liss, Inc.