New time-series statistic for detecting rhythmic co-occurrence in the frequency domain: The weighted coherence and its application to psychophysiological research

The relationships among physiological systems and between physiological and behavioral systems have frequently been evaluated with traditional descriptive statistics. These methods may not be sensitive to underlying rhythmic relationships. Although cross-spectral analysis provides a method for assessing rhythmic co-occurrence, it is only capable of describing the covariation of 2 systems at specific frequencies. Since physiological and behavioral systems tend not to be manifested at a constant frequency, a new statistic is described that is capable of evaluating the shared rhythmicity of 2 systems across an entire band of frequencies. (13 ref)