Sensitivity of MEG and EEG to Source Orientation
Open Access
- 18 July 2010
- journal article
- research article
- Published by Springer Science and Business Media LLC in Brain Topography
- Vol. 23 (3), 227-232
- https://doi.org/10.1007/s10548-010-0154-x
Abstract
An important difference between magnetoencephalography (MEG) and electroencephalography (EEG) is that MEG is insensitive to radially oriented sources. We quantified computationally the dependency of MEG and EEG on the source orientation using a forward model with realistic tissue boundaries. Similar to the simpler case of a spherical head model, in which MEG cannot see radial sources at all, for most cortical locations there was a source orientation to which MEG was insensitive. The median value for the ratio of the signal magnitude for the source orientation of the lowest and the highest sensitivity was 0.06 for MEG and 0.63 for EEG. The difference in the sensitivity to the source orientation is expected to contribute to systematic differences in the signal-to-noise ratio between MEG and EEG.Keywords
This publication has 38 references indexed in Scilit:
- Regional Differences in the Sensitivity of MEG for Interictal Spikes in EpilepsyBrain Topography, 2010
- Combining fMRI with EEG and MEG in order to relate patterns of brain activity to cognitionInternational Journal of Psychophysiology, 2009
- Cancellation of EEG and MEG signals generated by extended and distributed sourcesHuman Brain Mapping, 2009
- Mapping the signal‐to‐noise‐ratios of cortical sources in magnetoencephalography and electroencephalographyHuman Brain Mapping, 2008
- A novel integrated MEG and EEG analysis method for dipolar sourcesNeuroImage, 2007
- Influence of tissue conductivity anisotropy on EEG/MEG field and return current computation in a realistic head model: A simulation and visualization study using high-resolution finite element modelingNeuroImage, 2006
- Electromagnetic brain mappingIEEE Signal Processing Magazine, 2001
- Cortical Surface-Based Analysis: I. Segmentation and Surface ReconstructionNeuroImage, 1999
- Non-invasive detection of neuronal population activity in human hippocampusCognitive Brain Research, 1996
- EEG versus MEG localization accuracy: Theory and experimentBrain Topography, 1991