Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children's baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic association (inverted U-shape curve) between baseline vagal tone and prosociality (Kogan et al., 2014). The present research examined whether this nonlinear association was evident in children. The authors found consistent evidence for a quadratic relation between vagal tone and prosociality across 3 samples of children using 6 different measures. Compared to low and high vagal tone, moderate vagal tone in early childhood concurrently predicted greater self-reported prosociality (Study 1), observed empathic concern in response to the distress of others and greater generosity toward less fortunate peers (Study 2), and longitudinally predicted greater self-, mother-, and teacher-reported prosociality 5.5 years later in middle childhood (Study 3). Taken together, the findings suggest that moderate vagal tone at rest represents a physiological preparedness or tendency to engage in different forms of prosociality across different contexts. Early moderate vagal tone may reflect an optimal balance of regulation and arousal that helps prepare children to sympathize, comfort, and share with others. (PsycINFO Database Record

The links among mothers' compassionate love for their child, autonomic nervous system activity, and parenting behavior during less and more challenging mother-child interactions were examined. Mothers expressed and reported less negative affect when they exhibited autonomic patterns of increased parasympathetic dominance (high parasympathetic and low sympathetic activation) or autonomic coactivation (high parasympathetic and high sympathetic activation) during the less challenging interaction and autonomic coactivation during the more challenging interaction. Compassionate love predicted less reported and observed negativity in mothers who showed increased sympathetic nervous system dominance (high sympathetic and low parasympathetic activation). Compassionate love appeared to help mothers, and particularly those who experienced strong physiological arousal during difficult parenting situations, establish positive socialization contexts for their children and avoid stress-induced adverse parenting.

Altruism, although costly, may promote well-being for people who give. Costly giving by adults has received considerable attention, but less is known about the possible benefits, as well as biological and environmental correlates, of altruism in early childhood. In the current study, we present evidence that children who forgo self-gain to help other people show greater vagal flexibility and higher subsequent vagal tone than children who do not, and children from less wealthy families behave more altruistically than those from wealthier families. These results suggest that (a) altruism should be viewed through a biopsychosocial lens, (b) the influence of privileged contexts on children's willingness to make personal sacrifices for others emerges early, and (c) altruism and healthy vagal functioning may share reciprocal relations in childhood. When children help others at a cost to themselves, they could be playing an active role in promoting their own well-being as well as the well-being of others.

Individual differences in children's prosocial behaviors, including their willingness to give up something of value for the benefit of others, are rooted in physiological and environmental processes. In a sample of 4-year-old children, we previously found evidence that flexible changes in respiratory sinus arrhythmia (RSA) were linked to donation behavior, and that these physiological patterns may support greater sensitivity to the positive effects of compassionate parenting on donation behavior. The current study focused on a follow-up assessment of these children at age 6. First, we examined the stability of individual differences in donation behavior and related parasympathetic nervous system (PNS) activity from age 4 to 6. Second, we examined associations between donation behavior and RSA at 6 years. Third, we examined whether the association between children's RSA and donation behavior at age 6 varied depending on mothers' compassionate love. We found low to modest stability in donation behavior and RSA reactivity from age 4 to 6. These findings provide preliminary evidence that stable individual differences in altruism, as reflected by generosity, and in some aspects of parasympathetic functioning during opportunities to be prosocial, emerge in childhood. In addition, we found that some of the same associations between donation behavior, RSA, and compassionate love that we previously observed in children at 4 years of age continued to be evident 2 years later at age 6. Greater decreases in RSA when given the opportunity to donate were associated with children donating more of their own resources which, in turn, were associated with greater RSA recovery after the task. Lastly, mothers' compassionate love was positively associated with donation behavior in children who demonstrated stronger decreases in RSA during the task; compassionate parenting and RSA reactivity may serve as external and internal supports for prosociality that build on each other. Taken together, these findings contribute to the perspectives that individual differences in altruistic behaviors are intrinsically linked to healthy vagal flexibility, and that biopsychosocial approaches provide a useful framework for examining and understanding the environmental and physiological processes underlying these individual differences.

BACKGROUND: The nature of medical emergencies places emergency physicians at risk for high levels of acute psychological stress (APS). Stress-modifying techniques like visualization, breath control, and mental practice may help mitigate APS, but objective markers of stress are difficult to measure in the clinical setting. We explored the relationship between heart rate variability (HRV), a real-time measure of autonomic arousal, and self-reported APS among emergency medicine (EM) residents learning to intubate on actual patients. METHODS: This was a prospective study of postgraduate year 1 (PGY-1) EM residents at a single academic medical center during their 1-month anesthesia rotation. We obtained repeated measures of HRV immediately before and during the first intubation attempt each day. Participants completed the modified Spielberger State-Trait Anxiety Inventory (STAI-6) before intubation attempts and scored intubation difficulty using the Intubation Difficulty Scale. We analyzed HRV using root mean square of successive differences and analyzed data using clustered data methods and Pearson correlation coefficients. RESULTS: We enrolled eight PGY-1 residents and recorded 64 intubations. Mean HRV in the 2 minutes before intubation (17.88 ± 9.22) and during intubation (21.17 ± 13.46) was significantly lower than resting baseline (32.09 ± 15.23; adjusted mean difference [95% CI] = -13.90 [-20.35 to -7.45], p < 0.001; and -10.77 [-17.65 to -3.88], p = 0.02). Preintubation anxiety was negatively correlated with HRV (r = -0.39 [-0.58 to -0.16], p = 0.001). Intubation difficulty was not significantly correlated with HRV (r = -0.12 [-0.36 to 0.13], p = 0.35). CONCLUSIONS: HRV shows promise as a real-time index of autonomic arousal and may serve as an outcome measure in the evaluation of stress-modifying interventions.

Physiological synchrony within a dyad, or the degree of temporal correspondence between two individuals' physiological systems, has become a focal area of psychological research. Multiple methods have been used for measuring and modeling physiological synchrony. Each method extracts and analyzes different types of physiological synchrony, where 'type' refers to a specific manner through which two different physiological signals may correlate. Yet, to our knowledge, there is no documentation of the different methods, how each method corresponds to a specific type of synchrony, and the statistical assumptions embedded within each method. Hence, this article outlines several approaches for measuring and modeling physiological synchrony, connects each type of synchrony to a specific method, and identifies the assumptions that need to be satisfied for each method to appropriately extract each type of synchrony. Furthermore, this article demonstrates how to test for between-dyad differences of synchrony via inclusion of dyad-level (i.e., time-invariant) covariates. Finally, we complement each method with an empirical demonstration, as well as online supplemental material that contains Mplus code.

Experiencing maltreatment in early childhood predicts poor parasympathetic regulation, characterized by low baseline parasympathetic activity and strong withdrawal of parasympathetic influence in response to tasks. The Promoting First Relationships^® (PFR) program improves parental sensitivity toward young children in families identified as maltreating. Using a subsample from a randomized control trial, we examined whether parental participation in PFR had lasting effects on toddlers' parasympathetic regulation, as measured by respiratory sinus arrhythmia (RSA), relative to a resource and referral control condition. In addition, we examined whether parental sensitive and responsive behavior mediated or moderated associations between parent treatment group and children's RSA. More than 6 months after completing treatment, 29 families in the PFR condition and 30 families in the control condition were visited at home, and toddlers' RSA was assessed at baseline and during five moderately challenging tasks. Groups did not differ in baseline RSA, but differed in RSA reactivity to the tasks. Across tasks, toddlers of parents in the control condition manifested significantly larger RSA decreases than toddlers of parents in the PFR condition. Parental behavior showed divergent associations with RSA change for toddlers of parents in the PFR versus control condition, with PFR treatment predicting RSA change ranging from small decreases to increases in toddlers of parents who showed the most sensitive, responsive behavior in the 6 months following treatment. This preliminary study showed that the same intervention that improved parenting also improved toddlers' parasympathetic regulation in response to everyday activities, warranting further experimental investigation.

Irritability is common in Attention-Deficit Hyperactivity Disorder (ADHD), but little is known about whether irritability predicts the course of ADHD symptoms over time. Adolescence is a dynamic period of emotional development as well as shifts in ADHD symptoms; an important goal is to identify youth at risk of increasing or persisting symptoms. We examined irritability as a longitudinal predictor of change in adolescents' ADHD symptoms, as well as how this link may differ in females versus males. The sample included 108 youth (72 males) age 12-16 years (M = 14.21 years, SD = 1.44 years), 62 of whom met criteria for ADHD. Approximately 18 months later, 80 participants (48 males) were followed up at Time 2. A dimensional approach was used to examine changes over time in parent-reported inattentive and hyperactive/impulsive symptoms. Longitudinal path analysis revealed that irritability at Time 1 predicted higher relative hyperactive/impulsive symptoms at Time 2 after controlling for age and longitudinal stability in all variables. A multiple-group analysis examining moderation by sex/gender revealed that this association was significant only for females. These results suggest that irritability may play a key role in the persistence and worsening of hyperactive/impulsive symptoms across adolescence for females, with potential implications for the diagnosis and treatment of females with ADHD.

Background

The nature of medical emergencies places emergency physicians at risk for high levels of acute psychological stress (APS). Stress-modifying techniques like visualization, breath control, and mental practice may help mitigate APS, but objective markers of stress are difficult to measure in the clinical setting. We explored the relationship between heart rate variability (HRV), a real-time measure of autonomic arousal, and self-reported APS among emergency medicine (EM) residents learning to intubate on actual patients.

Methods

This was a prospective study of postgraduate year 1 (PGY-1) EM residents at a single academic medical center during their 1-month anesthesia rotation. We obtained repeated measures of HRV immediately before and during the first intubation attempt each day. Participants completed the modified Spielberger State-Trait Anxiety Inventory (STAI-6) before intubation attempts and scored intubation difficulty using the Intubation Difficulty Scale. We analyzed HRV using root mean square of successive differences and analyzed data using clustered data methods and Pearson correlation coefficients.

Results

We enrolled eight PGY-1 residents and recorded 64 intubations. Mean HRV in the 2 minutes before intubation (17.88 ± 9.22) and during intubation (21.17 ± 13.46) was significantly lower than resting baseline (32.09 ± 15.23; adjusted mean difference [95% CI] = -13.90 [-20.35 to -7.45], p < 0.001; and -10.77 [-17.65 to -3.88], p = 0.02). Preintubation anxiety was negatively correlated with HRV (r = -0.39 [-0.58 to -0.16], p = 0.001). Intubation difficulty was not significantly correlated with HRV (r = -0.12 [-0.36 to 0.13], p = 0.35).

Conclusions

HRV shows promise as a real-time index of autonomic arousal and may serve as an outcome measure in the evaluation of stress-modifying interventions.