Abstract: A time series from a human electroencephalogram (EEG) is used as a local perturbation to a reaction-diffusion model with spatio-temporal chaos.For certain finite ranges of amplitude and frequency it is observed that the strongly irregular perturbations can induce transient coherence in the chaotic system. This could be interpreted as "on-line" detection of an inherently correlated pattern embedded in the EEG.
Summary: Electrical activity as measured by EEG is a complicated mixture of many local nerve cell events within the human brain. It is generally assumed that many of these local events, for instance cognitive processes, contribute to the EEG in the form of short-term patterns with correlations.
Among the myriads of activities going on at the same time such transient patterns are not detectable by conventional methods of analysis. We have developed a method to automatically search for such short-term events without the need for further sophisticated analysis. The method employs a novel type of dynamics called "excitable chaos" to perform continuous processing of highly irregular input signals like EEG. Presently we are optimizing the procedure to search for a given specific event which might have clinical applications, for instance, in predicting an epileptic seizure.
- Human Electroencephalogram Induces Transient Coherence In Excitable Spatio-Temporal Chaos, Gerold Baier, Ron S. Leder, and P. Parmananda, Physical Review Letters volume 84 issue 19, pages 4501-4504, 2000
- Contributed by Gerold Baier