Table 1.

Overview of the RQA features used in this study.

RQA measure name	Equation
Recurrence rate	RR $=\frac{1}{N^2}\sum _{i,j=1}^{N}R(i,j)$
Determinism	DET $=\frac{\sum _{\ell ={\ell }_{min}}^N\ell P(\ell )}{\sum _{i,j=1}^{N}R(i,j)}$
Laminarity	LAM $=\frac{\sum _{v=v_{min}}^{N}vP(v)}{\sum _{v=1}^{N}vP(v)}$
Ratio	RATIO $=N^2\frac{\sum _{\ell ={\ell }_{min}}^N\ell P(\ell )}{{(\sum _{l=1}^{N}P(\ell ))}^2}$
Average diag. length	L $=\frac{\sum _{\ell ={\ell }_{min}}^N\ell P(\ell )}{\sum _{\ell ={\ell }_{min}}^{N}P(\ell )}$
Trapping time	TT $=\frac{\sum _{v=v_{min}}^{N}vP(v)}{\sum _{v=v_{min}}^{N}P(v)}$
Entropy	ENTR $=-\sum _{\ell ={\ell }_{min}}^{N}p(\ell )lnp(\ell )$
Longest diag. line	${\text{L}}_{max}=max({\left\{{\ell }_i\right\}}_{i=1}^{N_{\ell }})$
Longest vert. line	${\text{V}}_{max}=max({\left\{v_i\right\}}_{i=1}^{N_v})$

ℓ and v are the length of diagonal and vertical lines in recurrence plots, respectively, ℓ_min and v_min are the minimal diagonal and vertical length that should be considered. The total number of diagonal and vertical lines of lengths ℓ and v is expressed as histograms P(ℓ) and P(v), respectively. While p(ℓ) and p(v) describe the estimated length distributions, $N_{\ell }=\sum _{\ell \ge {\ell }_{min}}P(\ell )$ is the total number of diagonal lines and, similarly, N_v the total number of vertical lines.