Figure 2. Group comparisons between individuals with values above and below the median of values.

Individuals with higher values had lower neuroticism (a), and higher positive emotion scores (b). Moreover, individuals with higher values had lower normalized LF power, higher normalized HF power, and a lower LF/HF ratio (c). Abbrevations: LF (n.u.): low frequency power (0.04–0.15 Hz) of the HRV in normalized units; HF (n.u.): high frequency power (0.15–0.4 Hz) of the HRV in normalized units; LF/HF: ratio of low frequency power to high frequency power.