The relation between maternal emotional support and child physiological regulation across the preschool years

Parents regulate arousal while sharing experiences with their child: a study of pupil diameter change responses

Introduction

Parents provide their children with their first exposures to reciprocal shared experiences, and parental modeling of socio-emotional behaviors and regulatory responses largely influences their child's behavioral and neurological development. Some parental reactions are conscious, while others are non-volitional. This project aimed to explore parent-child pupil dilation change responses during shared interactions, specifically, whether parents' neuro-regulatory responses when sharing experiences with their child are different than responses of children interacting with their parents or children and adult peers sharing with each other.

Methods

To test this, four distinct interacting groups were recruited: (1) Parents sharing with their child; (2) Children sharing with their parent; (3) Children sharing with peers; and (4) Adults sharing with peers. All dyads engaged in a computerized shared imagery task, which facilitates communication and mental imagery during a shared experience. During the task, pupil diameter change was recorded as a measure of regulatory response.

Results

Findings highlight that parents sharing with their child have lower pupil diameter change than children sharing with their parents (p < 0.01), children sharing with peers (p < 0.01), and adults sharing with peers (p < 0.05), While no differences were seen between children sharing with parents, children sharing with peers or adults sharing with peers.

Discussion

Findings deepen the understanding of the neuroscience of parenting, by suggesting that parents, even of older children and adolescents, tend to regulate their arousal when interacting with their child, a response that proves to be unique compared to other dyad types for sharing experiences. Considering this dynamic, findings may direct future parent-led intervention methods to improve the child's socio-emotional development.

A systematic review and meta-analysis of the association between parenting and child autonomic nervous system activity

Parental socialization may influence the development of children's autonomic nervous system (ANS), a key stress-response system. However, to date no quantitative synthesis of the literature linking parenting and child ANS physiology has been conducted. To address this gap, we conducted a pre-registered meta-analysis. A systematic review of the literature identified 103 studies (n = 13,044 participants) with available effect sizes describing the association between parenting and either parasympathetic nervous system (PNS) or sympathetic nervous system (SNS) activity in children. The overall analysis revealed non-significant associations between parenting and child ANS physiology on average. However, moderation analyses revealed a positive association between more positive parenting and higher resting PNS activity that was stronger when a study was experimental rather than correlational, and when the sample included children with a clinical condition. In conclusion, well-controlled experimental studies show that positive parenting is associated with the development of higher resting PNS activity, an effect that may be stronger among children who are at elevated developmental risk.

Respiratory Sinus Arrhythmia Change during Trauma-Focused Cognitive-Behavioral Therapy: Results from a Randomized Controlled Feasibility Trial

Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT) is a well-established treatment for pediatric posttraumatic stress disorder (PTSD). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT that may improve treatment effects through enhanced targeting of affect regulation, as indexed by specific changes in the respiratory sinus arrhythmia (RSA). The current study reports results from a randomized controlled feasibility trial (N = 33; M_age = 11.79 [SD = 3.08]; 64% White; 67% female) that measured RSA during Sessions 1, 4, 8, and 12 of a twelve-session TF-CBT protocol and tested whether: 1) TF-CBT + AAT achieved higher average RSA amplitudes relative to TF-CBT alone, and 2) RSA regulation, defined as less variability around person-specific RSA slopes during treatment, explained variation in post-treatment PTSD symptoms. Multilevel modeling failed to support an effect for TF-CBT + AAT on RSA amplitudes (δ₀₀₁ = 0.08, p = 0.844). However, regardless of treatment condition, greater RSA withdrawal was observed within Sessions 4 (γ₁₁ = -.01, p < .001) and 12 (γ₁₃ = -.01, p = .015) relative to the Session 1 baseline. The average level of RSA amplitude in Session 8 was also significantly lower compared to Session 1 (γ₀₂ = -0.70, p = .046). Intraindividual regression models demonstrated that greater RSA regulation predicted improved PTSD symptoms at post-treatment after adjusting for pre-treatment levels (b₃ = 20.00, p = .012). These preliminary results offer support for future confirmatory trials testing whether affect regulation, as indexed by changes in RSA, is a mechanism of action for TF-CBT in the treatment of pediatric PTSD.

Trajectories of behavioral avoidance in real time: Associations with temperament and physiological dysregulation in preschoolers

Although excessive avoidance has been implicated in mental health problems and socioemotional difficulties, relatively little is known about dynamic changes of avoidance behaviors. We used a latent class growth analysis to examine the temporal course of avoidance behaviors in real time and determined whether the derived classes were distinguishable on temperament and physiological markers of regulation and reactivity (N = 153; M_age = 4.20 years). A three-class solution was found and identified a low, medium, and high increasing avoidance group. The high and increasing avoidance group had the highest physiological reactivity (cortisol reactivity) and shyness, and the lowest physiological regulation (i.e., respiratory sinus arrythmia suppression). High and increasing avoidance may therefore be associated with temperamental and physiological indices of risk implicated in maladjustment and highlight the value of data-driven, group-based approaches for examining dynamic patterns of behavior.

Who do we miss when screening for postpartum depression? A population-based study in a Swedish region

BACKGROUND

Universal screening for postpartum depression is crucial for early detection, interventions and support. The aim of this study was to describe the proportion of, and explore risk factors for, women not being offered screening, as well as for declining an offer or not being screened due to any other unknown reason.

METHODS

Socioeconomic, obstetrical and neonatal data, extracted from the Swedish Pregnancy Registry, for 9,959 pregnancies recorded for the Östergötland county between 2016 and 2018 were linked to Edinburgh Postnatal Depression Scale (EPDS) screening results at 6-8 weeks postpartum, extracted from medical records. Risk factors were assessed using logistic regression models and with a nomogram for easy visualization.

RESULTS

In total, there were no recorded offers of EPDS screening in the medical records for 30.0% of women at the postpartum follow-up. Women born outside of Sweden and women reporting poor self-rated health were at increased risk of not being offered screening for postpartum depression.

LIMITATIONS

There is a possibility that women were offered screening or were screened, but this was incorrectly or never recorded in medical records.

CONCLUSIONS

The majority of women were offered screening for postpartum depression, but there is room for improvement in order to achieve universal screening. Awareness among healthcare providers of the risk factors for not screening might increase adherence to guidelines for universal screening. Overcoming barriers for screening and raising the topic of mental-health issues for postpartum women should be prioritized.

Quantifying the dynamic nature of vagal responsivity in infancy: Methodological innovations and theoretical implications

According to polyvagal theory, rapid modulation of the vagal brake develops early in infancy and supports social interactions. Despite being viewed as a dynamic system, researchers typically assess vagal regulation using global measures of respiratory sinus arrhythmia (RSA; an index of vagal tone). This study sought to capture the dynamic property of RSA and evaluate individual differences in within-infant RSA responsivity during mother-infant interaction. RSA was evaluated in a sample of 135 6-month-old Mexican-American infants during a 5-min free play task. Mothers reported on their children's behavioral problems and competence at 18 months using the Brief Infant-Toddler Social and Emotional Assessment. Time-varying estimates of infant RSA during the interaction were obtained using a multiple window technique and spectrogram analysis. Using structural equation modeling, we evaluated whether within-infant SD of RSA predicted infants' behavioral problems and competence at 18 months, after adjusting for infants' mean RSA and covariates. Greater within-infant SD of RSA predicted more behavior problems at 18 months. This study demonstrates that assessing intra-individual variability in RSA, or the extent to which infants fluctuate around their average level of RSA during a task, enhances our ability to test polyvagal theory's central tenet: vagal regulation supports well-regulated social interaction.

Latent profiles of children's autonomic nervous system reactivity early in life predict later externalizing problems

Prior researchers have observed relations between children's autonomic nervous system reactivity and externalizing behavior problems, but rarely considers the role of developmentally regulated changes in children's stress response systems. Using growth mixture modeling, the present study derived profiles of parasympathetic nervous system reactivity (as indicated by respiratory sinus arrhythmia (RSA)) and sympathetic nervous system reactivity (as indicated by pre-ejection period (PEP)) from low income, primarily Mexican American children measured repeatedly from infancy through age 5 (N = 383) and investigated whether profiles were associated with externalizing problems at age 7. Analyses identified two profiles of RSA reactivity (reactive decreasing and U-shaped reactivity) and three profiles of PEP reactivity (blunted/anticipatory reactivity, reactive decreasing, non-reactive increasing). Compared to children with an RSA profile of reactive decreasing, those with an RSA profile of U-shaped reactivity had marginally higher externalizing problems, however, this difference was not statistically significant. Children who demonstrated a profile of blunted/anticipatory PEP reactivity had significantly higher externalizing problems compared to those with a profile of non-reactive increasing, likely related to the predominantly male composition of the former profile and predominantly female composition of the latter profile. Findings contribute to our understanding of developmental trajectories of ANS reactivity and highlight the utility of a longitudinal framework for understanding the effects of physiological risk factors on later behavior problems.

Preschoolers' dynamic respiratory sinus arrhythmia (RSA) change during a challenging parent-child interactive task: Relations with preschoolers' socioemotional health

Respiratory sinus arrhythmia (RSA) is a biomarker of physiological functioning that has been implicated in self-regulatory processes and shown to relate to children's socioemotional health. RSA is a dynamic process reflecting an individual's response to their environment; thus, temporally sensitive methods are critical to better understanding this self-regulatory process in different contexts. Prior work has studied young children's RSA change in the context of emotion clips and interactions with a stranger. The present study meaningfully expanded upon this work by examining: (a) preschoolers' dynamic RSA change during a challenging task with their mothers, and (b) factors that may explain variability in children's dynamic RSA change. Preschoolers (N = 108; M_age  = 3.56 years) and their mothers from diverse backgrounds completed a challenging activity together while children's physiological activity was monitored. Mothers reported on children's positive affect, parent emotional support, and family cohesion and indicators of socioemotional health. Children's positive affect and family cohesion explained variability in children's dynamic RSA change, which concurrently related to better socioemotional health. This study advances research and theory on biological correlates implicated in the development of children's self-regulation and furthers our understanding of factors that may support children's developing self-regulation at the physiological level.

Childhood Parental Warmth and Heart Rate Variability in Midlife: Implications for Health

The current study investigated high-frequency heart rate variability (HF-HRV) as a potential mediator between childhood parental warmth and later health and mortality outcomes. Participants were 1,255 adults (56.9% female). Childhood parental warmth was reported retrospectively at mean age 46; resting HF-HRV was measured at mean age 57; cardiovascular health and self-evaluated health were assessed at mean age 57 and 63, and mortality records extracted at mean age 63. Results revealed a positive association between childhood parental warmth and resting HF-HRV, as well as associations between higher HF-HRV and reduced risk of having a later cardiovascular health problem and of mortality by age 63. Mediation analyses revealed a small significant indirect effect of parental warmth, through HF-HRV, on cardiovascular health.

Distribution, Stability, and Continuity of Autonomic Nervous System Responsivity at 18- and 36-Months of Age

OBJECTIVE

Cardiac autonomic nervous system (ANS) measures, respiratory sinus arrhythmia (RSA) and preejection period (PEP), are valid and reliable indicators of children's sensitivity to their environment; however, there are few studies of ANS measures in children less than three years of age. This study's aim was to summarize the distributions, stability, and continuity of RSA and PEP measures during resting, challenge, and reactivity for children at 18- and 36-months.

METHODS

This was a cohort study of racially- and ethnically-diverse, low-income children who completed a developmentally challenging protocol while we simultaneously assessed their RSA and PEP at 18-months (N = 134) and 36-months (N = 102).

RESULTS

The ANS resting, challenge, and reactivity measures at 18- and 36-months of age were normally distributed. The RSA resting (r = 0.29), RSA challenge (r = 0.44), PEP resting (r = 0.55) and PEP challenge (r = 0.58) measures were moderately stable but RSA (r = 0.01) and PEP reactivity (r = 0.02) were not stable from 18- to 36-months of age. There was no continuity in the ANS measures from 18- to 36-months of age with statistically significant changes in sample means for all of the ANS measures.

DISCUSSION

These developmental changes in ANS are shown at the sample level but there are individual differences in ANS responses from 18- to 36-months that may be affected by adversity or protective factors experienced early in life.

Quantifying the dynamic nature of vagal responsivity in infancy: Methodological innovations and theoretical implications

According to polyvagal theory, rapid modulation of the vagal brake develops early in infancy and supports social interactions. Despite being viewed as a dynamic system, researchers typically assess vagal regulation using global measures of respiratory sinus arrhythmia (RSA; an index of vagal tone). This study sought to capture the dynamic property of RSA and evaluate individual differences in within-infant RSA responsivity during mother-infant interaction. RSA was evaluated in a sample of 135 6-month-old Mexican-American infants during a 5-min free play task. Mothers reported on their children's behavioral problems and competence at 18 months using the Brief Infant-Toddler Social and Emotional Assessment. Time-varying estimates of infant RSA during the interaction were obtained using a multiple window technique and spectrogram analysis. Using structural equation modeling, we evaluated whether within-infant SD of RSA predicted infants' behavioral problems and competence at 18 months, after adjusting for infants' mean RSA and covariates. Greater within-infant SD of RSA predicted more behavior problems at 18 months. This study demonstrates that assessing intra-individual variability in RSA, or the extent to which infants fluctuate around their average level of RSA during a task, enhances our ability to test polyvagal theory's central tenet: vagal regulation supports well-regulated social interaction.

Revisiting the double-edged sword of self-regulation: Linking shyness, attentional shifting, and social behavior in preschoolers

Although children's self-regulation has been conceptualized positively, there may be individual differences in self-regulatory processes, some of which might not be adaptive depending on temperamental factors. We examined whether individual differences in children's self-regulation (i.e., inhibitory control and attentional shifting) moderated the association between shyness and social behavior in multiple social contexts (N = 156 children, 74 girls; M_age = 4.06 years, SD = 0.78). Only in children with high attentional shifting was shyness associated with lower levels of social support seeking during a frustration task and with lower levels of social engagement during a stranger approach task. These results were not attributable to differences in baseline physiological arousal indexed by respiratory sinus arrhythmia. These findings suggest that for some shy children, high levels of self-regulation may be less adaptive, leading to rigidity or over-control in some social contexts, possibly hindering social interaction.

Maternal socialization of child emotion and adolescent adjustment: Indirect effects through emotion regulation

A fundamental question in developmental science is how parental emotion socialization processes are associated with children's subsequent adaptation. Few extant studies have examined this question across multiple developmental periods and levels of analysis. Here, we tested whether mothers' supportive and nonsupportive reactions to their 5-year-old children's negative emotions were associated with teacher and adolescent self-reported adjustment at age 15 via children's physiological and behavioral emotion regulation at age 10 (N = 404). Results showed that maternal supportive reactions to their children's negative emotions were associated with children's greater emotion regulation in a laboratory task and also a composite of mother and teacher reports of emotion regulation at age 10. Maternal nonsupportive reactions to their children's negative emotions were uncorrelated with supportive reactions, but were associated with poorer child physiological regulation and also poorer mother- and teacher-reported emotion regulation at age 10. In turn, better physiological regulation at age 10 was associated with more adolescent-reported social competence at age 15. Furthermore, teacher and mother reports of emotion regulation at age 10 were associated with increased adolescent adjustment across all domains. Mediational effects from nonsupportive and supportive reactions to adolescent adjustment tested via bootstrapping were significant. Our findings suggest that mothers' reactions to their children's negative emotions in early childhood may play a role in their children's ability to regulate their arousal both physiologically and behaviorally in middle childhood, which in turn may play a role in their ability to manage their emotions and behaviors and to navigate increasingly complex social contexts in adolescence. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Autonomic nervous system functioning in early childhood: Responses to cognitive and negatively valenced emotional challenges

Although autonomic nervous system (ANS) functioning is "context-dependent," few studies examined children's normative sympathetic and parasympathetic autonomic responses to distinct challenges in early childhood years. Examining children's ANS responsivity to distinct challenges is important for understanding normative autonomic responses toward everyday life stressors and identifying paradigms that effectively elicit a "stress response." We examined children's (N = 278) sympathetic (preejection period [PEP]) and parasympathetic (respiratory sinus arrhythmia [RSA]) responses to cognitive (i.e., problem-solving and cognitive control) and negatively valenced emotional (i.e., blocked goal and unfairness) challenges in preschool, kindergarten, and grade 1. Children, on average, demonstrated parasympathetic inhibition (RSA withdrawal) in response to all challenges but the magnitude of these responses depended on the task. Children showed sympathetic activation (PEP shortening) toward the problem-solving task at each assessment and there was no sample-level change in the magnitude of this response over time. Children showed greater sympathetic responsivity toward the cognitive control task over time, with evidence for a sympathetic activation response only in grade 1. Children experienced sympathetic inhibition (PEP lengthening) toward the unfairness tasks but did not experience significant sympathetic responsivity toward the blocked goal tasks. Parasympathetic responsivity to most challenges were modestly stable but there was no stability in sympathetic responsivity across time.

Observer-rated environmental sensitivity moderates children's response to parenting quality in early childhood

According to several developmental theories some children are more sensitive to the quality of their environment than others, but most supporting empirical evidence is based on relatively distal markers of hypothesized sensitivity. This study provides evidence for the validity of behaviorally observed Environmental Sensitivity as a moderator of parenting effects on children's early development in a sample of 292 children (Mage = 3.74; SD = 0.26) and their mothers. Sensitivity was coded using a newly developed observational measure for the specific and objective assessment of Environmental Sensitivity, the Highly Sensitive Child-Rating System (HSC-RS). HSC-RS factorial structure, associations with temperament traits, and interactions with parenting quality in the prediction of socioemotional child outcomes are reported. Findings supported a 1-factor solution. Observed sensitivity was relatively distinct from observed temperament and interacted with both low and high parenting quality in the development of behavior problems and social competence at ages 3 and 6. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Parental gentle encouragement promotes shy toddlers' regulation in social contexts

Gentle encouragement to approach appears to reduce risk for anxiety and is commonly incorporated into parenting interventions for inhibited preschoolers, yet little is known regarding whether gentle encouragement facilitates in-the-moment regulation as shy or inhibited children face social novelty, particularly during the toddler period. The current study used a sample of 55 temperamentally shy toddlers (21-24 months old) to examine toddler regulation in novel social contexts in relation to parental gentle encouragement to engage. Contexts included low-threat social novelty (i.e., a clown and puppets) and moderately threatening social novelty (i.e., strangers). Using an experimental design, parents were randomly assigned to provide behaviors thought to represent gentle encouragement: warm responsiveness to toddler fear and encouragement of toddler autonomy, prompt to engage, both warmth and prompt, or remaining uninvolved (no-encouragement control). Relative to toddlers in the no-encouragement control condition, toddlers whose parents were instructed to provide warmth showed less fear and more engagement in moderately threatening social contexts, and toddlers whose parents were instructed to provide both warmth and prompts showed greater suppression of respiratory sinus arrhythmia in low-threat social contexts. Findings suggest that parental gentle encouragement may promote regulated responses in social contexts in shy toddlers. Encouragement of toddler autonomy and warm responsiveness to toddlers in particular may help shy toddlers to engage with, rather than withdraw from, new people.

Stress and parenting predict changes in adolescent respiratory sinus arrhythmia

Adolescence is a critical period for the development of physiological emotion regulatory systems. While stressful life experiences are known to inhibit adaptive regulation, less is known about how parental socialization of emotion regulation may affect this relation. We examined the effect of stressful life experiences on changes in the resting respiratory sinus arrhythmia (RSA) levels of 107 (M_age  = 12.84, SD = 0.85) young adolescents over a year, moderated by supportive parental responses to negative emotions. The significant interaction (B = 0.02, p = 0.04) indicated that young adolescents who experienced low levels of supportive parenting in the context of high levels of stressful life experiences showed significant decreases in resting RSA over the year, while adolescents who experienced high levels of supportive parenting showed minimal decreases in RSA. Thus, more supportive parenting significantly compensated for the effect of greater stressful life experiences on changes in resting RSA over time.

Physiological self-regulation and mindfulness in children with a diagnosis of fetal alcohol spectrum disorder

OBJECTIVE

To explore the differences in baseline respiratory sinus arrhythmia (RSA) between children with fetal alcohol spectrum disorder (FASD) and typically developing children (TDC) and to investigate whether children with FASD have the capacity to engage in a brief mindfulness exercise.

METHODS

Participants were 14 children with FASD and 20 TDC. RSA was measured at baseline, during, and following a mindfulness exercise. A mindfulness compliance checklist was completed to ascertain if children could follow the task instructions.

RESULTS

Both groups obtained high scores on the mindfulness compliance checklist. There was a trend for children with FASD to have lower baseline RSA compared to TDC. Children in both groups demonstrated an increase in RSA during the mindfulness task.

CONCLUSIONS

Children with FASD could engage in a mindfulness task, and both groups showed an increase in RSA. Further research is needed to establish whether prolonged mindfulness practice could be beneficial.

Parenting and Cortisol in Infancy Interactively Predict Conduct Problems and Callous-Unemotional Behaviors in Childhood

This study examines observed maternal sensitivity, harsh-intrusion, and mental-state talk in infancy as predictors of conduct problems (CP) and callous-unemotional (CU) behaviors in middle childhood, as well as the extent to which infants' resting cortisol and cortisol reactivity moderate these associations. Using data from the Family Life Project (n = 1,292), results indicate that maternal sensitivity at 6 months predicts fewer CP at first grade, but only for infants who demonstrate high levels of cortisol reactivity. Maternal harsh intrusion predicts fewer empathic-prosocial behaviors, a component of CU behaviors, but only for infants who demonstrate high resting cortisol. Findings are discussed in the context of diathesis-stress and differential susceptibility models.

Inhibitory control in typically developing preschoolers: Relations among temperament, respiratory sinus arrhythmia, and behavior at age 4

Although inhibitory control (IC) is associated with children's positive adjustment, we know relatively little about factors underlying its development. We examined whether baseline and on-task respiratory sinus arrhythmia [(RSA); a physiological measure of self-regulation] and private speech (a behavioral measure of self-regulation) interacted to confer differences on directly observed IC in 52 typically developing 4-year olds. We found that baseline RSA moderated the association between private speech and IC, such that private speech positively predicted IC in children with relatively higher baseline RSA, but was unrelated to IC in children with relatively lower RSA. We also found that children with a concordant physiological-behavioral pattern (i.e., high RSA and high private speech; low RSA and low private speech) had higher IC, higher effortful control, and lower negative emotionality than those with a discordant physiological-behavioral pattern (i.e., high RSA and low private speech; low RSA and high private speech). Individual differences in physiological and behavioral self-regulation indices may represent distinct regulation pathways that interact to confer differences in IC during the preschool years.

Maternal Responsiveness Protects Exuberant Toddlers from Experiencing Behavior Problems in Kindergarten

RESEARCH FINDINGS

Exuberant temperament, characterized by high approach and positive affect, is linked to socioemotional outcomes including risk for externalizing symptoms across development. Externalizing problems interfere with children's school readiness and lead to disruptive behavior in the classroom. While some moderating factors help identify which exuberant children are at risk and in which contexts they are at risk, few studies have identified early moderators that protect against maladjustment when children enter school. In the current study, we examined exuberant temperament in 124 toddlers and classroom behavior problems reported by kindergarten teachers. We also assessed the impact of maternal responsiveness at 24 months on the relation between exuberance and classroom behavior problems. As hypothesized, we found that higher exuberance predicted more behavior problems. Additionally, maternal responsiveness moderated this association such that high responsiveness protected exuberant children from classroom behavior problems.

PRACTICE OR POLICY

These results expand our understanding of socioemotional risks for exuberant children and how these risks influence school readiness. We also find that maternal responsiveness during toddlerhood mitigates these risks, and our findings suggest that interventions for exuberant children at risk for behavior problems or poor school readiness should target parental responsiveness when children are toddlers.

Approaches to modeling the development of physiological stress responsivity

Influential biopsychosocial theories have proposed that some developmental periods in the lifespan are potential pivot points or opportunities for recalibration of stress response systems. To date, however, there have been few longitudinal studies of physiological stress responsivity and no studies comparing change in physiological stress responsivity across developmental periods. Our goals were to (a) address conceptual and methodological issues in studying the development of physiological stress responsivity within and between individuals, and (b) provide an exemplar for evaluating development of responsivity to stress in the parasympathetic nervous system, comparing respiratory sinus arrhythmia (RSA) responsivity from middle to late childhood with middle to late adolescence. We propose the use of latent growth modeling of stress responsivity that includes time-varying covariates to account for conceptual and methodological issues in the measurement of physiological stress responsivity. Such models allow researchers to address key aspects of developmental sensitivity including within-individual variability, mean level change over time, and between-individual variability over time. In an empirical example, we found significant between-individual variability over time in RSA responsivity to stress during middle to late childhood but not during middle to late adolescence, suggesting that childhood may be a period of greater developmental sensitivity at the between-individual level.

Neurobiology of infant attachment: attachment despite adversity and parental programming of emotionality

We review recent findings related to the neurobiology of infant attachment, emphasizing the role of parenting quality in attachment formation and emotional development. Current findings suggest that the development of brain structures important for emotional expression and regulation (amygdala, prefrontal cortex, hippocampus) is deeply associated with the quality of care received in infancy, with sensitive caregiving providing regulation vital for programming these structures, ultimately shaping the development of emotion into adulthood. Evidence indicates that without sensitive caregiving, infants fail to develop mechanisms needed for later-life emotion and emotion regulation. Research suggests that a sensitive period exists in early life for parental shaping of emotional development, although further cross-species research is needed to discern its age limits, and thus inform interventions.

Preschoolers' genetic, physiological, and behavioral sensitivity factors moderate links between parenting stress and child internalizing, externalizing, and sleep problems

This study examined three potential moderators of the relations between maternal parenting stress and preschoolers' adjustment problems: a genetic polymorphism-the short allele of the serotonin transporter (5-HTTLPR, ss/sl allele) gene, a physiological indicator-children's baseline respiratory sinus arrhythmia (RSA), and a behavioral indicator-mothers' reports of children's negative emotionality. A total of 108 mothers (M_age  = 30.68 years, SD_age  = 6.06) reported on their parenting stress as well as their preschoolers' (M_age  = 3.50 years, SD_age  = 0.51, 61% boys) negative emotionality and internalizing, externalizing, and sleep problems. Results indicated that the genetic sensitivity variable functioned according to a differential susceptibility model; however, the results involving physiological and behavioral sensitivity factors were most consistent with a diathesis-stress framework. Implications for prevention and intervention efforts to counter the effects of parenting stress are discussed.

Vagal Regulation of Cardiac Function in Early Childhood and Cardiovascular Risk in Adolescence

OBJECTIVE

Poor behavioral self-regulation in the first 2 decades of life has been identified as an important precursor of disease risk in adulthood. However, physiological regulation has not been well studied as a disease risk factor before adulthood. We tested whether physiological regulation at the age of 2 years, in the form of vagal regulation of cardiac function (indexed by respiratory sinus arrhythmia [RSA] change), would predict three indicators of cardiovascular risk at the age of 16 years (diastolic and systolic blood pressure and body mass index).

METHODS

Data came from 229 children who participated in a community-based longitudinal study. At the age of 2 years, children were assessed for RSA baseline and RSA change (ln(ms)) in response to a series of challenge tasks. These same children were assessed again at the age of 16 years for diastolic and systolic blood pressure (millimeters of mercury), height (meters), and weight (kilogram).

RESULTS

Regression analyses revealed that less RSA withdrawal at the age of 2 years predicted higher diastolic blood pressure at the age of 16 years, adjusting for demographic characteristics (B = -3.07, M [S E] = 1.12, p = .006). Follow-up analyses demonstrated that these predictions extended to clinically significant levels of diastolic prehypertension (odds ratio = 0.43, 95% confidence interval = 0.22-0.89). RSA withdrawal did not significantly predict adolescent body mass index or systolic blood pressure.

CONCLUSIONS

Vagal regulation of cardiac function in early childhood predicts select indicators of cardiovascular risk 14 years later. Early signs of attenuated vagal regulation could indicate an increased risk for elevated blood pressure before adulthood. Future research should test biological, behavioral, and psychological mechanisms underlying these long-term predictions.

Test-Retest Reliability of Pediatric Heart Rate Variability: A Meta-Analysis

Heart rate variability (HRV), an established index of autonomic cardiovascular modulation, is associated with health outcomes (e.g., obesity, diabetes) and mortality risk. Time- and frequency-domain HRV measures are commonly reported in longitudinal adult and pediatric studies of health. While test-retest reliability has been established among adults, less is known about the psychometric properties of HRV among infants, children, and adolescents. The objective was to conduct a meta-analysis of the test-retest reliability of time- and frequency-domain HRV measures from infancy to adolescence. Electronic searches (PubMed, PsycINFO; January 1970-December 2014) identified studies with nonclinical samples aged ≤ 18 years; ≥ 2 baseline HRV recordings separated by ≥ 1 day; and sufficient data for effect size computation. Forty-nine studies (N = 5,170) met inclusion criteria. Methodological variables coded included factors relevant to study protocol, sample characteristics, electrocardiogram (ECG) signal acquisition and preprocessing, and HRV analytical decisions. Fisher's Z was derived as the common effect size. Analyses were age-stratified (infant/toddler < 5 years, n = 3,329; child/adolescent 5-18 years, n = 1,841) due to marked methodological differences across the pediatric literature. Meta-analytic results revealed HRV demonstrated moderate reliability; child/adolescent studies (Z = 0.62, r = 0.55) had significantly higher reliability than infant/toddler studies (Z = 0.42, r = 0.40). Relative to other reported measures, HF exhibited the highest reliability among infant/toddler studies (Z = 0.42, r = 0.40), while rMSSD exhibited the highest reliability among child/adolescent studies (Z = 1.00, r = 0.76). Moderator analyses indicated greater reliability with shorter test-retest interval length, reported exclusion criteria based on medical illness/condition, lower proportion of males, prerecording acclimatization period, and longer recording duration; differences were noted across age groups. HRV is reliable among pediatric samples. Reliability is sensitive to pertinent methodological decisions that require careful consideration by the researcher. Limited methodological reporting precluded several a priori moderator analyses. Suggestions for future research, including standards specified by Task Force Guidelines, are discussed.

Preschoolers' psychophysiological responses to mood induction tasks moderate the intergenerational transmission of internalizing problems

To identify factors that can both exacerbate risk for, and protect against, internalizing problems during early childhood, the present study examined whether children's respiratory sinus arrhythmia (RSA) suppression in response to emotionally-laden film clips would moderate the association between maternal and child anxious/depressive symptoms in a cross-sectional sample of 108 mothers (M age=30.68years, SD=6.06) and their preschool-age children (M age=3.50years, SD=0.52, 61.30% male). Results indicated that RSA suppression in response to the fear clip moderated the positive association between maternal and child anxious/depressive symptoms, such that higher suppression served a protective-stabilizing function while lower suppression exacerbated children's risk for internalizing symptoms in the context of higher maternal symptoms. Moderation findings involving RSA suppression in response to a happiness-inducing clip were consistent with biological sensitivity to context; the association between maternal and child symptoms was strongest for children higher in suppression.

Indirect Effects of Maternal Sensitivity on Infant Emotion Regulation Behaviors: The Role of Vagal Withdrawal

The potential indirect effect of observed maternal sensitivity at 5 months on the development of infants' behavioral regulation of emotion from 5 to 10 months (i.e., distraction and maternal-orientation behaviors) via infant's vagal withdrawal was investigated (N = 230). Results indicated that maternal sensitivity at 5 months was not directly associated with behavioral regulation at 10 months. However, greater maternal sensitivity at 5 months was associated with greater vagal withdrawal at 10 months, after controlling for vagal withdrawal at 5 months. Further, vagal withdrawal at 10 months was associated with greater orientation toward the mother at 10 months, after controlling for 5-month orientation behaviors. The indirect effect of maternal sensitivity on maternal-orientation behaviors was significant, suggesting that infant's vagal withdrawal may be one potential mechanism through which maternal sensitivity is related to behavioral regulation.

Trajectories of internalizing symptoms across childhood: The roles of biological self-regulation and maternal psychopathology

Whether internalizing symptoms increase or remain at similar levels throughout childhood is currently not well understood. Moreover, the association between vagal regulation of cardiac activity and internalizing symptoms across childhood needs to be clarified. We used a multilevel conceptual framework to examine how children's vagal regulation of cardiac activity and mothers' internalizing symptoms were jointly associated with children's developmental trajectories of internalizing symptoms from ages 4 to 10 years old. Data came from 384 children who participated in an ongoing longitudinal study. Children and their mothers came to the research laboratory at ages 4, 5, 7, and 10. Mothers reported their children's and their own internalizing symptoms. Children's vagal regulation of cardiac activity was assessed during quiet baseline tasks and during challenge tasks. Multilevel models revealed that child internalizing symptoms increased from ages 4 to 10 years old, but only in females, and especially between ages 7 and 10. More vagal withdrawal in response to challenge was associated with more internalizing symptoms, particularly with more somatic symptoms. Associations between children's physiological regulation and internalizing symptoms differed by children's age, sex, and presence of maternal internalizing symptoms. Understanding associations between vagal regulation of cardiac activity and internalizing symptoms during childhood calls for fine-grained developmental analyses that take into account the heterogeneity of internalizing symptoms, as well as developmental phase, context, and gender.

Early physiological regulation predicts the trajectory of externalizing behaviors across the preschool period

Early assessments of children's physiological functioning are shown to predict subsequent developmental outcomes. However, individual changes that occur in the development of physiological systems may be associated with the pattern of change in behavior across time. Thus, we examined change in respiratory sinus arrhythmia (RSA), an index of physiological regulation, as a time-varying predictor in order to assess whether RSA change at ages 3, 4, and 5 uniquely influenced the trajectory of externalizing behaviors from age 3 to 5. Results indicated that only at age 3 was RSA change significantly associated with decreases in externalizing behaviors over time. RSA change scores at ages 4 and 5 were unrelated to trajectories of externalizing behavior, suggesting that the ability to physiologically regulate by age 3 may contribute to the development of skills that facilitate more control over behavior throughout preschool, and therefore may be more strongly associated with the pattern of change in externalizing behaviors than later physiological regulation.

A transactional analysis of the relation between maternal sensitivity and child vagal regulation

A transactional model examining the longitudinal association between vagal regulation (as indexed by vagal withdrawal) and maternal sensitivity from age 2.5 to age 5.5 was assessed. The sample included 356 children (171 male, 185 female) and their mothers who participated in a laboratory visit at age 2.5, 4.5, and 5.5. Cardiac vagal tone was obtained during a baseline task and during emotional frustration tasks. Maternal sensitivity was assessed via direct observation during a pretend play and cleanup task. To test for transactional associations, a path model estimating stability paths for vagal withdrawal and maternal sensitivity was compared with a full reciprocal model that included all cross-lagged pathways. A chi-square difference test was used to evaluate whether the cross-lagged model explained the data above and beyond the stability model. The vagal withdrawal cross-lagged model was found to fit significantly better than the stability model and revealed that maternal sensitivity at 2.5 years was associated positively with vagal withdrawal at 4.5 years, and vagal withdrawal at 4.5 years was associated positively with maternal sensitivity at 5.5 years. These results suggest that early sensitive responding by mothers was associated with increases in vagal withdrawal, which in turn was associated with higher levels of sensitive parenting.