Sensitivity of MEG and EEG to Source Orientation
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. Si...
Main Authors: | , , , |
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Other Authors: | |
Format: | Article |
Language: | en_US |
Published: |
Springer
2011
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Online Access: | http://hdl.handle.net/1721.1/64950 https://orcid.org/0000-0001-6841-112X |
Summary: | 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. |
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