TY - JOUR A1 - Drenhaus, Heiner A1 - Beim Graben, Peter A1 - Saddy, Douglas A1 - Frisch, Stefan T1 - On the processing of negative polarity constructions revealed by the symbolic resonance analysis Y1 - 2005 SN - 0898-929X ER - TY - JOUR A1 - Brehm-Jurish, Eva Ute A1 - Saddy, Douglas T1 - On cohesion and coherence in text processing : two ERP studies Y1 - 2005 SN - 0898-929X ER - TY - JOUR A1 - Beim Graben, Peter A1 - Frisch, Stefan A1 - Fink, A. A1 - Saddy, Douglas A1 - Kurths, Jürgen T1 - Topographic voltage and coherence mapping of brain potentials by means of the symbolic resonance analysis N2 - We apply the recently developed symbolic resonance analysis to electroencephalographic measurements of event- related brain potentials (ERPs) in a language processing experiment by using a three-symbol static encoding with varying thresholds for analyzing the ERP epochs, followed by a spin-flip transformation as a nonlinear filter. We compute an estimator of the signal-to-noise ratio (SNR) for the symbolic dynamics measuring the coherence of threshold-crossing events. Hence, we utilize the inherent noise of the EEG for sweeping the underlying ERP components beyond the encoding thresholds. Plotting the SNR computed within the time window of a particular ERP component (the N400) against the encoding thresholds, we find different resonance curves for the experimental conditions. The maximal differences of the SNR lead to the estimation of optimal encoding thresholds. We show that topographic brain maps of the optimal threshold voltages and of their associated coherence differences are able to dissociate the underlying physiological processes, while corresponding maps gained from the customary voltage averaging technique are unable to do so Y1 - 2005 SN - 1539-3755 ER -