Bayesian Inference for Neural Electromagnetic Source Localization: Analysis of MEG Visual Evoked Activity

Conference · Mon Feb 01 00:00:00 EST 1999

OSTI ID:7429

George, J S; Schmidt, D M; Wood, C C

We have developed a Bayesian approach to the analysis of neural electromagnetic (MEG/EEG) data that can incorporate or fuse information from other imaging modalities and addresses the ill-posed inverse problem by sarnpliig the many different solutions which could have produced the given data. From these samples one can draw probabilistic inferences about regions of activation. Our source model assumes a variable number of variable size cortical regions of stimulus-correlated activity. An active region consists of locations on the cortical surf ace, within a sphere centered on some location in cortex. The number and radi of active regions can vary to defined maximum values. The goal of the analysis is to determine the posterior probability distribution for the set of parameters that govern the number, location, and extent of active regions. Markov Chain Monte Carlo is used to generate a large sample of sets of parameters distributed according to the posterior distribution. This sample is representative of the many different source distributions that could account for given data, and allows identification of probable (i.e. consistent) features across solutions. Examples of the use of this analysis technique with both simulated and empirical MEG data are presented.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Institutes of Health (NIH)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7429
• Report Number(s): LA-UR-99-554; ON: DE00007429
• Resource Relation: Conference: SPIE Medical Imaging Conference, San Diego, CA, February 20-26, 1999
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
Brain
Diagnostic Techniques
Markov Process
Monte Carlo Method
Electromagnetic Fields