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A method for estimating long-range power law correlations from the electroencephalogram.

Paul A Watters·Frances Martin
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Abstract

Recent research has found long-range electroencephalogram (EEG) power law correlations, indicating time scale invariance. However, the EEG is also rather noisy, displaying short-term decorrelation like white noise--i.e., what is scale invariant at one time period may disappear in the next. The paradoxical combination of short-range divergence, but long-range correlations, suggests that any long-range correlations detected in one sample may be spurious, since they could be related to amplitude fluctuations. To overcome this problem, this paper suggests a new technique for analysing EEG signals segmented by zero-crossings, using detrended fluctuation analysis (DFA), evaluated across two time periods (TIME) and different sites (SITE). A mean scaling exponent across all subjects and sites of alpha = 0.67 was observed. MANOVA analysis indicates no significant main effect for TIME or interaction with SITE, suggesting that the zero-crossing method may be successful in determining the fractal nature of EEG dynamics across relatively long time scales.

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Cerebral CortexElectroencephalographyHumansModels, TheoreticalPeriodicityReproducibility of ResultsJournal ArticleResearch Support, Non-U.S. Gov't

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Paul A Watters, Frances Martin. 2004. A method for estimating long-range power law correlations from the electroencephalogram.. https://doi.org/10.1016/j.biopsycho.2003.09.001

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