title: Distinguishing between moving and stationary sources using EEG/MEG measurements with an application to epilepsy.
abstract: Performances of electroencephalography (EEG) and magnetoencephalography (MEG) source estimation methods depend on the validity of the assumed model. In many cases, the model structure is related to physical information. We discuss a number of statistical selection methods to distinguish between two possible models using least-squares estimation and assuming a spherical head model. The first model has a single moving source whereas the second has two stationary sources; these may result in similar EEG/MEG measurements. The need to decide between such models occurs for example in Jacksonian seizures (e.g., epilepsy) or in intralobular activities, where a model with either two stationary dipole sources or a single moving dipole source may be possible. We also show that all of the selection methods discussed choose the correct model with probability one when the number of trials goes to infinity. Finally we present numerical examples and compare the performances of the methods by varying parameters such as the signal-to-noise ratio, source depth, and separation of sources, and also apply the methods to real MEG data for epilepsy.
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA. syetik@ece.uic.edu
authors.forename: Imam Samil
authors.initials: IS
authors.lastname: Yetik
authors.forename: Arye
authors.initials: A
authors.lastname: Nehorai
authors.forename: Jeffrey David
authors.initials: JD
authors.lastname: Lewine
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Muravchik
mesh_terms: D000465:Algorithms; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004569:Electroencephalography / Q000379:methods*; D004574:Electromagnetic Fields; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology*; D006257:Head / Q000503:physiopathology; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008959:Models, Neurological; D015233:Models, Statistical; D009038:Motion; D013269:Stochastic Processes; D013997:Time Factors