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Regularized two-step brain activity reconstruction from spatio-temporal EEG data

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Published in Image Reconstruction from Incomplete Data III, SPIE International Symposium on Optical Science and Technology. Denver (USA) - Aug 2-6 - . 2004
Collection SPIE proceedings; 5562
Abstract We are aiming at using EEG source localization in the framework of a Brain Computer Interface project. We propose here a new reconstruction procedure, targeting source (or equivalently mental task) differentiation. EEG data can be thought of as a collection of time continuous streams from sparse locations. The measured electric potential on one electrode is the result of the superposition of synchronized synaptic activity from sources in all the brain volume. Consequently, the EEG inverse problem is a highly underdetermined (and ill-posed) problem. Moreover, each source contribution is linear with respect to its amplitude but non-linear with respect to its localization and orientation. In order to overcome these drawbacks we propose a novel two-step inversion procedure. The solution is based on a double scale division of the solution space. The first step uses a coarse discretization and has the sole purpose of globally identifying the active regions, via a sparse approximation algorithm. The second step is applied only on the retained regions and makes use of a fine discretization of the space, aiming at detailing the brain activity. The local configuration of sources is recovered using an iterative stochastic estimator with adaptive joint minimum energy and directional consistency constraints.
Keywords ElectroencephalographyBrainComputing systemsElectrodesInterfacesInverse problemsSource localizationSuperposition
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Note Publié aussi dans: Joint AMI, PASCAL, (IM)2, M4 Workshop on Multimodal Interaction and related machine learning algorithms, Martigny (Switzerland), 21-23 June 2004
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Research groups Computer Vision and Multimedia Laboratory
Multimodal Interaction Group
Stochastic Information Processing Group
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ALECU, Teodor, VOLOSHYNOVSKYY, Svyatoslav, PUN, Thierry. Regularized two-step brain activity reconstruction from spatio-temporal EEG data. In: Image Reconstruction from Incomplete Data III, SPIE International Symposium on Optical Science and Technology. Denver (USA). [s.l.] : [s.n.], 2004. (SPIE proceedings; 5562) https://archive-ouverte.unige.ch/unige:47710

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Deposited on : 2015-03-06

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