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Updated: Dec 31, 2025

Cortical Source Analysis of High-Density EEG Recordings in Children
Published on: June 30, 2014
Localization of sparse and coherent sources by orthogonal least squares
Gilles Chardon1, François Ollivier2, José Picheral1
1Université Paris-Saclay, CNRS, CentraleSupélec, Laboratoire des signaux et systèmes, 91190 Gif-sur-Yvette, France.
This study introduces an efficient method for locating signal sources and estimating their covariance, significantly reducing computational complexity for high-dimensional problems. The novel approach enhances accuracy and simplifies source correlation matrix estimation without needing regularization parameters.
Area of Science:
- Signal Processing
- Array Signal Processing
- Computational Electromagnetics
Background:
- Estimating signal covariance is crucial for analyzing correlated sources, often found with distributed sources or reflections.
- Existing methods face computational complexity challenges, limiting their application in high-dimensional scenarios.
Purpose of the Study:
- To propose an efficient method for joint source localization and signal covariance estimation.
- To overcome the computational complexity associated with traditional covariance matrix estimation techniques.
Main Methods:
- Covariance Matrix Fitting by Orthogonal Least Squares (CMF-OLS).
- A greedy dictionary-based approach utilizing the orthogonal least squares algorithm.
- Exploiting orthogonal least squares to reduce computational load.
Main Results:
- The proposed method significantly reduces computational complexity compared to existing techniques.
- Achieves higher accuracy in source correlation matrix estimation.
- Demonstrates capability in handling high-dimensional problems and exploring extensive source position spaces.
- Successfully locates and identifies physical and mirror sources in experimental settings.
Conclusions:
- The CMF-OLS method offers an efficient and accurate solution for joint source localization and covariance estimation.
- Its reduced complexity enables analysis of complex scenarios with fine spatial discretization.
- Experimental validation confirms its effectiveness with correlated sources and reflectors.
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