About 70 million people worldwide are affected by dysfunction of the autonomic nervous system (ANS). These dysfunctions can lead to life-threatening conditions, because ANS controls vital functions like heart rate, digestion, respiration, among others. Spectral analysis of heart rate variability (HRV) allows noninvasive assessment of the ANS. However, the low frequencies (0.04-0.15 Hz) of HRV are influenced by the two complementary branches of the ANS, the sympathetic and parasympathetic nervous systems; hence, the spectral analysis cannot separate the dynamics of these autonomic tones. Developing reliable noninvasive techniques for assessment of the ANS dynamics remains a challenge for scientists. Recently, measure of electrodermal activit...