COGNITIVE NEUROSCIENCE AND NEUROPSYCHOLOGYDetection of early cognitive processing by event-related phase synchronization analysisAllefeld, Carsten1 2 CA; Frisch, Stefan1 3; Schlesewsky, Matthias1 4Author Information 1Research Unit ‘Conflicting Rules’, University of Potsdam, P.O. Box 601553, D-14415 Potsdam 2Nonlinear Dynamics Group, University of Potsdam 3Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 4Junior Research Group Neurolinguistics, Philipps University Marburg, Germany CACorresponding Author: [email protected] Received 27 November 2004; accepted 19 October 2004 NeuroReport: January 19, 2005 - Volume 16 - Issue 1 - p 13-16 Buy Abstract In order to investigate the temporal characteristics of cognitive processing, we apply multivariate phase synchronization analysis to event-related potentials. The experimental design combines a semantic incongruity in a sentence context with a physical mismatch (color change). In the ERP average, these result in an N400 component and a P300-like positivity, respectively. Synchronization analysis shows an effect of global desynchronization in the theta band around 288 ms after stimulus presentation for the semantic incongruity, while the physical mismatch elicits an increase of global synchronization in the alpha band around 204 ms. Both of these effects clearly precede those in the ERP average. Moreover, the delay between synchronization effect and ERP component correlates with the complexity of the cognitive processes. © 2005 Lippincott Williams & Wilkins, Inc.