EVENT SYNCHRONIZATION: A VERY SIMPLE AND FAST MEASURE OF SYNCHRONIZATION AND TIME DELAY PATTERNS
Abstract number :
1.134
Submission category :
Year :
2002
Submission ID :
3013
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Rodrigo Quian Quiroga, Thomas Kreuz, Klaus Lehnertz, Christian Elger, Peter Grassberger. Sloan-Swartz Center of Theoretical Neurobiology, California Institute of Technology, Pasadena, CA; John von Neumann Institute of Computing, Research Center Juelich, J
RATIONALE: We propose a simple method to measure synchronization and time delay patterns between EEG channels.
METHODS: The method is based on the relative timings of events in the time series, defined e.g. as local maxima. The degree of synchronization is obtained from the number of quasi-simultaneous appearances of events, and the delay is calculated from the precedence of events in one signal with respect to the other. Moreover, we can easily visualize the time evolution of the delay and synchronization level with an excellent resolution.
RESULTS: We show the application of the algorithm to intracranial human EEG recordings containing seizure activity and we propose that it might be useful for the detection of the epileptic foci.
CONCLUSIONS: Event synchronization gives an useful quantification of synchronicity and time delay patterns between EEG channels. The method can be easily extended to other types of data and it is very simple and fast, thus being suitable for on-line implementations.
[Supported by: Deutsche Forschungsgemeinschaft, SFB TR3. Sloan Swartz Foundation.]