“…In order to quantify time-correlations in recorded time series, we have used the DFA method [36,37], frequently applied in analysis of physiological data [25,[38][39][40][41]. The original time series X(t), t = 1, ..., N have been integrated Z(k) = k t=1 [X(t) − X], where X = N t=1 X(t)/N is the data mean and k is an integer number k ∈ {1, ..., N }.…”