Conditions of autonomic reciprocal interplay versus autonomic co-activation: Effects on non-linear heart rate dynamics

The stress of chess players as a model to study the effects of psychological stimuli on physiological responses: an example of substrate oxidation and heart rate variability in man

“…Furthermore, the interplay between the sympathetic and vagal regulation of HR is not always organized in a reciprocal fashion, wherein increased activity in one system is accompanied by decreased activity in the other. A simultaneous sympathetic and vagal activation has been observed during cold face immersion (Tulppo et al 2005), and also in other circumstances in healthy subjects (Mourot et al 2007). It is highly possible that increased sympathetic activation occurs without any change in vagal outflow during a demanding mental stress situation without exercise or body position changes, as in the present study.…”

Biophysiologic Effects of Warm Water Immersion

“…Safe, easily available nonpharmacologic methods of achieving this autonomic adjustment could have potential utility and applicability over a range of health care issues. Warm water immersion has been shown in some previous studies to have some significant effects upon the ANS, reducing SNS activity, and increasing PNS influence upon the ANS (Mourot et al, 2008;Mourot et al, 2007;Nagasawa et al, 2001;Nishimura & Onodera, 2000. The mood and cognitive effects of these autonomic adjustments reduce anxiety, increase working memory, increase executive function (a complex group of cognitive skills), and attentional regulation (Thayer & Brosschot, 2005).…”

Nonlinear Cardiac Dynamics

“…One thing is for sure -autonomic imbalance and heart rate variability are important risk factors for cardiovascular disease [32]. Importantly, the reciprocity or co-activation of the sympathetic and parasympathetic branches of the autonomic nervous system is decidedly non-linear [33] and non-Gaussian [34]. This being true, it becomes apparent and necessary to apply the proper nonlinear tools to assess the signals.…”