A new concept for EEG/MEG signal analysis: detection of interacting spatial modes.

We propose a new concept for analyzing EEG/MEG data. The concept is based on a projection of the spatiotemporal signal into the relevant phase space and the interpretation of the brain dynamics in terms of dynamical systems theory. The projection is obtained by a simultaneous determination of spatial modes and coefficients of differential equations. The resulting spatiotemporal model can be characterized by stationary points and corresponding potential field maps. Brain information processing can be interpreted by attraction and repulsion of spatial field distributions given by these stationary points. This allows an objective and quantitative characterization of the brain dynamics. We outline this concept and the underlying algorithm. Results of the application of this method to an event related potential (ERP) study of auditory memory processes are discussed.