Sensitivity of MEG and EEG to Source Orientation

被引:187
作者
Ahlfors, Seppo P. [1 ,2 ]
Han, Jooman [1 ]
Belliveau, John W. [1 ,2 ]
Haemaelaeinen, Matti S. [1 ,2 ]
机构
[1] Harvard Univ, Massachusetts Gen Hosp, Sch Med, MGH HST Athinoula A Martinos Ctr Biomed Imaging, Boston, MA 02129 USA
[2] Harvard Mit Div Hlth Sci & Technol, Cambridge, MA 02135 USA
关键词
Magnetoencephalography; Electroencephalography; Suppression ratio; Current dipole; Radial source current; SURFACE-BASED ANALYSIS; TO-NOISE-RATIOS; LOCALIZATION ACCURACY; HEAD MODEL; SIMULATION; BRAIN; MAGNETOENCEPHALOGRAPHY; ELECTROENCEPHALOGRAPHY; RECONSTRUCTION; ANISOTROPY;
D O I
10.1007/s10548-010-0154-x
中图分类号
R74 [神经病学与精神病学];
学科分类号
100204 [神经病学];
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.
引用
收藏
页码:227 / 232
页数:6
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