Sensitivity of MEG and EEG to Source Orientation

被引：0
作者：
Seppo P. Ahlfors
Jooman Han
John W. Belliveau
Matti S. Hämäläinen
机构：
[1] MGH/HST Athinoula A. Martinos Center for Biomedical Imaging,
[2] Massachusetts General Hospital/Harvard Medical School,undefined
[3] Harvard-MIT Division of Health Sciences and Technology,undefined
来源：
Brain Topography | 2010年 / 23卷
关键词：
Magnetoencephalography; Electroencephalography; Suppression ratio; Current dipole; Radial source current;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
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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页码：227 / 232
页数：5
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