Heart rate complexity during the temporary systems dedifferentiation

Abstract

The article describes the results of a study of correlation between parameters of heart rate variability and characteristics of system organization of behavior, which is considered as the dynamic actualization of functional systems of different “age”. The proportion of “old” (low-differentiated) and “new” (high-differentiated) systems defines the general degree of differentiation of the set of functional systems actualized in particular behavior. Heart rate variability reflects the coordination of activity of heart cells and other body cells. This coordination is the important for achieving adaptive behavioral results. We hypothesized that temporary system dedifferentiation (reversible decreasing the number of highly differentiated systems subserving behavior) is accompanied by reduction of heart rate complexity. Beat-to-beat intervals were recorded during stress (Experiment 1) and alcohol administration (Experiment 2). We used approximate entropy (ApEn) as a measure of heart rate complexity. The decrease of approximate entropy was observed in both stress and alcohol conditions. It is concluded that reversible system dedifferentiation is reflected in heart rate dynamics as a reduction of complexity.