Dynamics of Neurovisceral Interactions in Individual and Phylogenetic Development: Analysis of Heart Rate Variability

This article presents an overview of experimental studies addressing the nature of neurovisceral interactions by analysis of heart rate variability at different stages of individual development and in members of different species. Analysis of heart rate variability is one of the most common and accessible methods for observing and assessing aspects of neurovisceral (specifically, neurocardiac) interactions in experiments. Non-stationary, non-linear components in the dynamics of RR intervals (the time intervals between adjacent heartbeats) reflect the processes coordinating cardiac activity with changes in the organization of neural activity supporting the ongoing relationship of an individual with the environment. Mathematically, these aspects of heart rate dynamics are expressed as estimates of the complexity, irregularity, entropy, and unpredictability of the time sequence of interbeat intervals. The dynamics of neurocardiac interactions described in this way are different in different species and become more complex during phylogenesis. Similarly, during individual development, heart rate dynamics become more complex and reflect, among other things, the degree of maturation of certain neural structures at different stages of ontogenesis. We address the dynamics of neurovisceral interactions during individual and phylogenetic development within the framework of the systems-evolutionary approach and interpret them in relation to changes in the structure of individual experience, i.e., the characteristics of a set of functional systems actualized as behavior, i.e., increases in the level of differentiation of the individual’s relationships with the environment.