Quantifying time irreversibility using probabilistic differences between symmetric permutations

Publication date: Available online 28 November 2018Source: Physics Letters AAuthor(s): Wenpo Yao, Wenli Yao, Jun Wang, Jiafei DaiAbstractTo simplify the quantification of time irreversibility, we employ order patterns instead of the raw multi-dimension vectors in time series, and considering the existence of forbidden permutation, we propose a subtraction-based parameter to measure probabilistic differences between symmetric permutations for time irreversibility. Two chaotic models, logistic and Henon systems, and reversible Gaussian process and their surrogate data are used to validate the time-irreversible measure, and time irreversibility of real-world epileptic EEGs from Nanjing General Hospital is detected by the parameter. Test results prove that it is promising to quantify time irreversibility by measuring the subtraction-based probabilistic differences between symmetrical order patterns, and our findings suggest that epilepsy leads to a decline in the nonlinearity of brain activities during seize-free intervals and highlight the manifestation of nonlinearity of whether healthy or diseased brain electrical activities.
Source: Physics Letters A - Category: Physics Source Type: research