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Testing for time-localized coherence in bivariate data

Sheppard, L. W. and Stefanovska, A. and McClintock, P. V. E. (2012) Testing for time-localized coherence in bivariate data. Physical Review E, 85 (4). -. ISSN 1539-3755

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    Abstract

    We present a method for the testing of significance when evaluating the coherence of two oscillatory time series that may have variable amplitude and frequency. It is based on evaluating the self-correlations of the time series. We demonstrate our approach by the application of wavelet-based coherence measures to artificial and physiological examples. Because coherence measures of this kind are strongly biased by the spectral characteristics of the time series, we evaluate significance by estimation of the characteristics of the distribution of values that may occur due to chance associations in the data. The expectation value and standard deviation of this distribution are shown to depend on the autocorrelations and higher order statistics of the data. Where the coherence value falls outside this distribution, we may conclude that there is a causal relationship between the signals regardless of their spectral similarities or differences.

    Item Type: Article
    Journal or Publication Title: Physical Review E
    Additional Information: ©2012 American Physical Society
    Subjects: Q Science > QC Physics
    Departments: Faculty of Science and Technology > Physics
    ID Code: 54939
    Deposited By: ep_importer_pure
    Deposited On: 07 Jun 2012 14:57
    Refereed?: Yes
    Published?: Published
    Last Modified: 09 Apr 2014 23:38
    Identification Number:
    URI: http://eprints.lancs.ac.uk/id/eprint/54939

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