Synchronization as adjustment of information rates: Detection from bivariate time series - art. no. 046211

An information-theoretic approach for studying synchronization phenomena in experimental bivariate time series is presented. "Coarse-grained" informat ion rates are introduced and their ability to indicate generalized synchron ization as well as to establish a "direction of information flow" between c oupled systems, i.e., to discern the driving from the driven (response) sys tem, is demonstrated using numerically generated time series from unidirect ionally coupled chaotic systems. The method introduced is then applied in a case study of electroencephalogram recordings of an epileptic patient. Syn chronization events leading to seizures have been found on two levels of or ganization of brain tissues and "directions of information flow" among brai n areas have been identified. This allows localization of the primary epile ptogenic areas, also confirmed by magnetic resonance imaging and pasitron e mission tomography scans.