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Sparse EEG Source Localization Using Bernoulli Laplacian Priors

Costa, Facundo Hernan and Batatia, Hadj and Chaari, Lotfi and Tourneret, Jean-Yves Sparse EEG Source Localization Using Bernoulli Laplacian Priors. (2015) IEEE Transactions on Biomedical Engineering, 62 (12). 2888-2898. ISSN 0018-9294

(Document in English)

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Official URL: http://dx.doi.org/10.1109/TBME.2015.2450015


Source localization in electroencephalography has received an increasing amount of interest in the last decade. Solving the underlying ill-posed inverse problem usually requires choosing an appropriate regularization. The usual l2 norm has been considered and provides solutions with low computational complexity. However, in several situations, realistic brain activity is believed to be focused in a few focal areas. In these cases, the l2 norm is known to overestimate the activated spatial areas. One solution to this problem is to promote sparse solutions for instance based on the l1 norm that are easy to handle with optimization techniques. In this paper, we consider the use of an l0 + l1 norm to enforce sparse source activity (by ensuring the solution has few nonzero elements) while regularizing the nonzero amplitudes of the solution. More precisely, the l0 pseudonorm handles the position of the non zero elements while the l1 norm constrains the values of their amplitudes. We use a Bernoulli–Laplace prior to introduce this combined l0 + l1 norm in a Bayesian framework. The proposed Bayesian model is shown to favor sparsity while jointly estimating the model hyperparameters using a Markov chain Monte Carlo sampling technique. We apply the model to both simulated and real EEG data, showing that the proposed method provides better results than the l2 and l1 norms regularizations in the presence of pointwise sources. A comparison with a recent method based on multiple sparse priors is also conducted.

Item Type:Article
Additional Information:Thanks to IEEE Xplore. The definitive version is available at http://ieeexplore.ieee.org/Xplore/home.jsp The original PDF of the article can be found at: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7134742
HAL Id:hal-01261357
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Université de Toulouse > Université Toulouse - Jean Jaurès - UT2J (FRANCE)
Université de Toulouse > Université Toulouse 1 Capitole - UT1 (FRANCE)
Laboratory name:
Deposited On:25 Jan 2016 10:15

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