Eur. Phys. J. Plus (2012) 127: 140
https://doi.org/10.1140/epjp/i2012-12140-9

Regular Article

Variational Bayesian localization of EEG sources with generalized Gaussian priors

¹ Ikerbasque, The Basque Foundation for Science, E-48011, Bilbao, Spain
² Biocruces Health Research Institute, Hospital Universitario de Cruces, Plaza de Cruces s/n, E-48903, Barakaldo, Spain
³ Departamento de Lenguajes y Sistemas Informáticos, Universidad de Granada, E-18071, Granada, Spain
⁴ Departamento de Ciencias de la Computación e Inteligencia Artificial, Universidad de Granada, E-18071, Granada, Spain
⁵ Department of Electrical Engineering and Computer Science, Northwestern University, 60208-3118, Evanston, Illinois, USA

Received: 7 July 2012
Revised: 4 November 2012
Accepted: 5 November 2012
Published online: 23 November 2012

Abstract

Although in the last decades the use of Magnetic Resonance Imaging has grown in popularity as a tool for the structural analysis of the brain, including MRI, fMRI and recently DTI, the ElectroEncephaloGraphy (EEG) is, still today, an interesting technique for the understanding of brain organization and function. The main reason for this is that the EEG is a direct measure of brain bioelectrical activity, and such activity can be monitorized in the millisecond time window. For some situations and cognitive scenarios, such fine temporal resolution might suffice for some aspects of brain function; however, the EEG spatial resolution is very poor since it is based on a small number of scalp recordings, thus turning the source localization problem into an ill-posed one in which infinite possibilities exist for the localization of the neuronal generators. This is an old problem in computational neuroimaging; indeed, many methods have been proposed to overcome this localization. Here, by performing a Variational Bayesian Inference procedure with a generalized Gaussian prior, we come out with an algorithm that performs simultaneously the estimation of both sources and model parameters. The novelty for the inclusion of the generalized Gaussian prior allows to control the smoothness degree of the estimated sources. Finally, the suggested algorithm is validated on simulated data.