Measuring Cardiac Autonomic Nervous System (ANS) Activity in Toddlers - Resting and Developmental Challenges

Abstract

The autonomic nervous system (ANS) consists of two branches, the parasympathetic and sympathetic nervous systems, and controls the function of internal organs (e.g., heart rate, respiration, digestion) and responds to everyday and adverse experiences 1 . ANS measures in children have been found to be related to behavior problems, emotion regulation, and health 2-7. Therefore, understanding the factors that affect ANS development during early childhood is important. Both branches of the ANS affect young children's cardiovascular responses to stimuli and have been measured noninvasively, via external monitoring equipment, using valid and reliable measures of physiological change 8-11 . However, there are few studies of very young children with simultaneous measures of the parasympathetic and sympathetic nervous systems, which limits understanding of the integrated functioning of the two systems. In addition, the majority of existing studies of young children report on infants' resting ANS measures or their reactivity to commonly used mother-child interaction paradigms, and less is known about ANS reactivity to other challenging conditions. We present a study design and standardized protocol for a non-invasive and rapid assessment of cardiac autonomic control in 18 month old children. We describe methods for continuous monitoring of the parasympathetic and sympathetic branches of the ANS under resting and challenge conditions during a home or laboratory visit and provide descriptive findings from our sample of 140 ethnically diverse toddlers using validated equipment and scoring software. Results revealed that this protocol can produce a range of physiological responses to both resting and developmentally challenging conditions, as indicated by changes in heart rate and indices of parasympathetic and sympathetic activity. Individuals demonstrated variability in resting levels, responses to challenges, and challenge reactivity, which provides additional evidence that this protocol is useful for the examination of ANS individual differences for toddlers.

The Effects of a Prenatal Mindfulness Intervention on Infant Autonomic and Behavioral Reactivity and Regulation

“…Although the feasibility and reliability of collecting SNS data from infants have been established (59,60), very few studies have examined maternal health and behaviors during the prenatal period and infant sympathetic response (see, for exception, Refs. (12,15)).…”

Infant weight-for-length gain associated with autonomic nervous system reactivity

“…ANS regulation was collected continuously throughout the SFP using BioNex hardware and BioLab acquisition software version 3.0 (Mindware Technologies, Ltd., www.mindwaretech.com) via spot electrodes placed on the infants. The full ANS collection and scoring methods protocol have been previously described [28]. Parasympathetic nervous system reactivity was assessed using respiratory sinus arrhythmia (RSA; the naturally occurring variation in heart rate as a function of respiration).…”

Dynamics of mother‐infant parasympathetic regulation during face‐to‐face interaction: The role of maternal emotion dysregulation

“…Therefore, the SFP has become a standard laboratory procedure for evaluating the dynamics of mother‐infant interactions. In the current study, we operationalize individuals' homeostasis as their average RSA level during the Play episode, as with previous studies (Bush et al, 2016; Conradt & Ablow, 2010), to capture ordinary mother‐infant play interactions. This operationalization of homeostasis differs from the traditional understanding that focuses on physiological activity while at rest.…”