Before revision: Permutation relative entropy is proposed to quantify time irreversibilityin our nonlinear dynamics analysis of electroencephalogram (EEG). Ordinal patterns in multi-dimension phase space of time series are symbolized, and the probabilistic divergences of all symmetric ordinal pairs are measured by relative entropy as time irreversibility.
After revision: To simplify the quantification of time irreversibility, we employ order patterns instead of the raw multi-dimension phase space of time series are symbolized, and the probabilistic divergences of all symmetric ordinal pairs are measured by relative entropy as time irreversibility.