Source Activity Correlation Effects on LCMV Beamformers in a Realistic Measurement Environment
Joint Authors
Braun, Christoph
Belardinelli, Paolo
Ortiz, Erick
Source
Computational and Mathematical Methods in Medicine
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-8, 8 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-04-29
Country of Publication
Egypt
No. of Pages
8
Main Subjects
Abstract EN
In EEG and MEG studies on brain functional connectivity and source interactions can be performed at sensor or source level.
Beamformers are well-established source-localization tools for MEG/EEG signals, being employed in source connectivity studies both in time and frequency domain.
However, it has been demonstrated that beamformers suffer from a localization bias due to correlation between source time courses.
This phenomenon has been ascertained by means of theoretical proofs and simulations.
Nonetheless, the impact of correlated sources on localization outputs with real data has been disputed for a long time.
In this paper, by means of a phantom, we address the correlation issue in a realistic MEG environment.
Localization performances in the presence of simultaneously active sources are studied as a function of correlation degree and distance between sources.
A linear constrained minimum variance (LCMV) beamformer is applied to the oscillating signals generated by the current dipoles within the phantom.
Results show that high correlation affects mostly dipoles placed at small distances (1, 5 centimeters).
In this case the sources merge.
If the dipoles lie 3 centimeters apart, the beamformer localization detects attenuated power amplitudes and blurred sources as the correlation level raises.
American Psychological Association (APA)
Belardinelli, Paolo& Ortiz, Erick& Braun, Christoph. 2012. Source Activity Correlation Effects on LCMV Beamformers in a Realistic Measurement Environment. Computational and Mathematical Methods in Medicine،Vol. 2012, no. 2012, pp.1-8.
https://search.emarefa.net/detail/BIM-453160
Modern Language Association (MLA)
Belardinelli, Paolo…[et al.]. Source Activity Correlation Effects on LCMV Beamformers in a Realistic Measurement Environment. Computational and Mathematical Methods in Medicine No. 2012 (2012), pp.1-8.
https://search.emarefa.net/detail/BIM-453160
American Medical Association (AMA)
Belardinelli, Paolo& Ortiz, Erick& Braun, Christoph. Source Activity Correlation Effects on LCMV Beamformers in a Realistic Measurement Environment. Computational and Mathematical Methods in Medicine. 2012. Vol. 2012, no. 2012, pp.1-8.
https://search.emarefa.net/detail/BIM-453160
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-453160