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MEG versus EEG localization test using implanted sources in the human brain
Author(s) -
Cohen David,
Cuffin B. Neil,
Yunokuchi Kazutomo,
Maniewski Roman,
Purcell Christopher,
Cosgrove G. Rees,
Ives John,
Kennedy John G.,
Schomer Donald L.
Publication year - 1990
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.410280613
Subject(s) - electroencephalography , magnetoencephalography , signal (programming language) , pattern recognition (psychology) , brain mapping , artificial intelligence , eeg fmri , computer science , neuroscience , psychology , programming language
It is believed that the magnetoencephalogram (MEG) localizes an electrical source in the brain to within several millimeters and is therefore more accurate than electroencephalogram (EEG) localization, reported as 20 mm. To test this belief, the localization accuracy of the MEG and EEG were directly compared. The signal source was a dipole at a known location in the brain; this was made by passing a weak current pulse simulating a neural signal through depth electrodes already implanted in patients for seizure monitoring. First, MEGs and EEGs from this dipole were measured at 16 places on the head. Then, computations were performed on the MEG and EEG data separately to determine the apparent MEG and EEG source locations. Finally, these were compared with the actual source location to determine the MEG and EEG localization errors. Measurements were made of four dipoles in each of three patients. After MEGs with weak signals were discounted, the MEG average error of localization was found to be 8 mm, which was worse than expected. The average EEG error was 10 mm, which was better than expected. These results suggest that the MEG offers no significant advantage over the EEG in localizing a focal source. However, this does not diminish other uses of the MEG.