Figure 3: Quantification of MSE: Summation of the entropy over different scales was used to quantify the complexity over certain time scales.

The common profile of entropy gradually increased as the time scale increased and reached a plateau where information richness could be accumulated rapidly if the system responded well. Three parameters of the MSE were assessed: (1) the linear-fitted slope between scales 1–5 (slope 1–5); (2) the area under the curve between scales 1–5 (area 1–5), which was used to represent complexity between short scales; (3) the area under curve between scales 6–20 (area 6–20), which was used to represent complexity between long scales.