Developmental and contextual influences on autonomic reactivity in young children

Heart rate and heart rate variability in obsessive-compulsive disorder: Evidence from patients and unaffected first-degree relatives

Altered heart rate (HR) and heart rate variability (HRV) are common observations in psychiatric disorders. Yet, few studies have examined these cardiac measures in obsessive-compulsive disorder (OCD). The current study aimed to investigate HR and HRV, indexed by the root mean square of successive differences (RMSSD) and further time domain indices, as putative biological characteristics of OCD. Electrocardiogram was recorded during a five-minute resting state. Group differences between patients with OCD (n = 96), healthy participants (n = 112), and unaffected first-degree relatives of patients with OCD (n = 47) were analyzed. As potential moderators of group differences, we examined the influence of age and medication, respectively. As results indicated, patients with OCD showed higher HR and lower HRV compared to healthy participants. These group differences were not moderated by age. Importantly, subgroup analyses showed that only medicated patients displayed lower HRV compared to healthy individuals, while HR alterations were evident in unmedicated patients. Regarding unaffected first-degree relatives, group differences in HRV remained at trend level. Further, an age-moderated group differentiation showed that higher HRV distinguished relatives from healthy individuals in young adulthood, whereas at higher age lower HRV was indicative of relatives. Both the role of familial risk and medication in HRV alterations need further elucidation. Pending future studies, alterations in HR and potentially HRV might serve as useful indices to characterize the pathophysiology of OCD.

Autonomic nervous system responses to social stimuli among autistic individuals: A systematic review and meta-analysis

Physiological responses to environmental and social stimuli have been studied broadly in relation to psychological states and processes. This may be especially important regarding autistic individuals, who show disparities in social interactions. However, findings from studies assessing autonomic nervous system (ANS) responses of autistic individuals present contradictions, with reports showing both autonomic disparities and intact autonomic functioning. The current study aimed to review the existing literature and to estimate if there is a difference between autistic individuals and neurotypical (NT) individuals in their autonomic responses to social stimuli. Furthermore, the study examined factors that may moderate this difference, including the type of physiological function measured, the level of participation required, as well as the age and intellectual functioning of the participants. The meta-analysis revealed a small and statistically insignificant overall difference between autistic and NT individuals, albeit with high heterogeneity. A further nested moderator analysis revealed a significant difference between autistic and NT individuals in physiological response that reflects mainly a parasympathetic nervous system (PNS) activity. Another difference was found in physiological response that reflects a combined activity of the sympathetic and parasympathetic systems, but only for experimental tasks that demanded active participation in social interactions. These results suggest a distinctiveness in autonomic regulation of autistic individuals in social situations, and point to the PNS as an important study objective for future investigation.

Associations between cortical thickness and parasympathetic nervous system functioning during middle childhood

Positive associations have been found between cortical thickness and measures of parasympathetic cardiac control (e.g., respiratory sinus arrhythmia, RSA) in adults, which may indicate mechanistic integration between neural and physiological indicators of stress regulation. However, it is unknown when in development this brain-body association arises and whether the direction of association and neuroanatomical localization vary across development. To investigate this, we collected structural magnetic resonance imaging and resting-state respiratory sinus arrhythmia data from children in middle childhood (N = 62, Mage  = 10.09, range: 8.28-12.14 years). Whole-brain and exploratory ROI analyses revealed positive associations between RSA and cortical thickness in four frontal and parietal clusters in the left hemisphere and one cluster in the right. Exploratory ROI analyses revealed a similar positive association between cortical thickness and RSA, with two regions surviving multiple comparison correction, including the inferior frontal orbital gyrus and the Sylvian fissure. Prior work has identified these cortical areas as part of the central autonomic network that supports integrative regulation of stress response (e.g., autonomic, endocrine, and behavioral) and emotional expression. Our results suggest that the association between cortical thickness and resting RSA is present in middle childhood and is similar to the associations seen during adulthood. Future studies should investigate associations between RSA and cortical thickness among young children and adolescents.

Prenatal serotonin reuptake inhibitor antidepressant exposure, SLC6A4 genetic variations, and cortisol activity in 6-year-old children of depressed mothers: A cohort study

Prenatal exposure to maternal depression and serotonin reuptake inhibitor (SRI) antidepressants both affect the development of the hypothalamic-pituitary-adrenal (HPA) system, possibly via the neurotransmitter serotonin (5HT). In a community cohort, we investigated the impact of two factors that shape prenatal 5HT signaling (prenatal SRI [pSRI] exposure and child SLC6A4 genotype) on HPA activity at age 6 years. Generalized estimating equation (GEE) models were used to study associations between cortisol reactivity, pSRI exposure, and child SLC6A4 genotype, controlling for maternal depression, child age, and sex (48 pSRI exposed, 74 nonexposed). Salivary cortisol levels were obtained at five time points during a laboratory stress challenge: arrival at the laboratory, following two sequential developmental assessments, and then 20 and 40 min following the onset of a stress-inducing cognitive/social task. Cortisol decreased from arrival across both developmental assessments, and then increased across both time points following the stress challenge in both groups. pSRI-exposed children had lower cortisol levels across all time points. In a separate GEE model, we observed a lower cortisol stress response among children with LG /S alleles compared with children with La/La alleles, and this was particularly evident among children of mothers reporting greater third trimester depressed mood. Our findings suggest that pSRI exposure and a genetic factor associated with modulating 5HT signaling shaped HPA reactivity to a laboratory stress challenge at school age.

Risk for internalizing symptom development in young children: Roles of child parasympathetic reactivity and maternal depression and anxiety exposure in early life

Intergenerational transmission of internalizing disorders (anxiety and depression) is well documented, but the responsible pathways are underspecified. One possible mechanism is via programming of the child's parasympathetic nervous system (PNS). For example, maternal depression and anxiety, via multiple pathways, may heighten child PNS reactivity, which has been linked to increased risk for internalizing disorders. Heightened PNS reactivity also may sensitize a child to their environment, increasing the vulnerability to developing psychopathology when exposed to stressors, such as maternal psychopathology. In a prospective longitudinal study of mother-child dyads (N = 446), we examined relations among maternal depression and anxiety symptoms when children were infants and aged 3 and 5 years, child respiratory sinus arrythmia (RSA) reactivity (measure of PNS reactivity) at 3 years, and child internalizing symptoms at age 5 years. Consistent with an adaptive calibration perspective, analyses tested the roles of child RSA reactivity as both a mediator and a moderator of associations between maternal and child symptoms. Greater child RSA reactivity in response to a fearful video predicted higher internalizing symptoms among children exposed to higher levels of maternal depression or anxiety symptoms at age 5 years (moderation effects). Child RSA reactivity did not mediate relations between maternal depression or anxiety symptoms in infancy and child internalizing symptoms at age 5 years. The results suggest that heightened PNS reactivity may represent a biological vulnerability to stressful environments early in life: When coupled with maternal depression or anxiety exposure, child PNS reactivity may promote the development of internalizing psychopathology in early childhood.

Individual differences in social homeostasis

The concept of “social homeostasis”, introduced by Matthews and Tye in 2019, has provided a framework with which to consider our changing individual needs for social interaction, and the neurobiology underlying this system. This model was conceived as including detector systems, a control center with a setpoint, and effectors which allow us to seek out or avoid additional social contact. In this article, we review and theorize about the many different factors that might contribute to the setpoint of a person or animal, including individual, social, cultural, and other environmental factors. We conclude with a consideration of the empirical challenges of this exciting new model.

Autonomic nervous system activity moderates associations between temperament and externalizing behaviors in early childhood

Temperamental risk, such as surgency, negative affect, and poor effortful control, has been posited as a predictor of externalizing symptom development. However, autonomic nervous system (ANS) activity underlying processes of reactivity and regulation may moderate associations between early temperament and later externalizing behaviors during early childhood. The aim of the present study was to examine how interactions between resting sympathetic (SNS) and parasympathetic (PNS) activity at age 5 may moderate associations between temperamental risk at age 3 and externalizing behavior at age 6 (n = 87). Results demonstrate different interactions between resting ANS activity and temperamental risk to predict externalizing behaviors. For children with lower SNS activation at rest, surgency was positively associated with externalizing behaviors. Negative affect was positively associated with externalizing behaviors except when there were either high levels of SNS and PNS activity or low levels of SNS and PNS activity. Effortful control was not associated with externalizing behaviors, though SNS and PNS activity interacted to predict externalizing behaviors after accounting for effortful control. Taken together, the results highlight the importance to examine multisystem resting physiological activity as a moderator of associations between temperamental risk and the development of externalizing  behaviors.

Autonomic tone in children and adults: Pupillary, electrodermal and cardiac activity at rest

Considering the suspected involvement of the autonomic nervous system (ANS) in several neurodevelopmental disorders, a description of its tonus in typical populations and of its maturation between childhood and adulthood is necessary. We aimed to arrive at a better understanding of the maturation of the sympathetic (SNS) and parasympathetic (PNS) tonus by comparing children and adults at rest, via recordings of multiple ANS indices. We recorded simultaneously pupil diameter, electrodermal activity (EDA) and cardiac activity (RR interval and HRV: heart rate variability) in 29 children (6-12 years old) and 30 adults (20-42 years old) during a 5-min rest period. Children exhibited lower RR intervals, higher LF peak frequencies, and lower LF/HF (low frequency/high frequency) ratios compared to adults. Children also produced more spontaneous EDA peaks, reflected in a larger EDA AUC (area under the curve), in comparison with adults. Finally, children displayed a larger median pupil diameter and a higher pupillary hippus frequency than adults. Our results converged towards higher SNS and PNS tones in children compared to adults. Childhood would thus be characterized by a high autonomic tone, possibly reflecting a physiological state compatible with developmental acquisitions.

Autonomic profiles and self-regulation outcomes in early childhood

This study examined autonomic profiles in preschoolers (N = 278, age = 4.7 years) and their relations to self-regulation outcomes concurrently and one year later, in kindergarten. Children's sympathetic (preejection period [PEP]) and parasympathetic activity (respiratory sinus arrythmia [RSA]) were measured at rest and during cognitive and emotional tasks. Three self-regulatory competencies were assessed: executive functions, emotion regulation and behavioral regulation. Executive functioning was measured at ages 4 and 5 using laboratory tasks designed to assess updating/working memory, inhibitory control, and cognitive flexibility. Emotion regulation was observed during emotionally distressing tasks in the laboratory, both at ages 4 and 5. Behavioral regulation and emotional reactivity were assessed via teacher ratings in kindergarten, at age 5. Latent profile analysis yielded four autonomic profiles: moderate parasympathetic inhibition (45%), reciprocal sympathetic activation (26%), coinhibition (25%), and high sympathetic activation (7%). The reciprocal sympathetic activation group showed better executive functioning in preschool and kindergarten, particularly compared to the high sympathetic activation group. The moderate parasympathetic inhibition group showed lower emotional reactivity and better behavioral regulation in kindergarten, compared to the other three groups. Findings suggest that autonomic profiles meaningfully associate with self-regulation outcomes in early childhood, such that certain profiles relate to better self-regulation than others.

Coordination of autonomic and endocrine stress responses to the Trier Social Stress Test in adolescence

Dysregulations in autonomic and endocrine stress responses are linked to the emergence of psychopathology in adolescence. However, most studies fail to consider the interplay between these systems giving rise to conflicting findings and a gap in understanding adolescent stress response regulation. A multisystem framework-investigation of parasympathetic (PNS), sympathetic (SNS), and hypothalamic pituitary adrenal (HPA) axis components and their coordination-is necessary to understand individual differences in stress response coordination which contribute to stress vulnerabilities. As the first investigation to comprehensively evaluate these three systems in adolescence, the current study employed the Trier Social Stress Test in 72 typically developing adolescents (mean age = 13) to address how PNS, SNS, and HPA stress responses are coordinated in adolescence. Hypotheses tested key predictions of the Adaptive Calibration Model (ACM) of stress response coordination. PNS and SNS responses were assessed via heart rate variability (HRV) and salivary alpha amylase (sAA) respectively. HPA responses were indexed by salivary cortisol. Analyses utilized piecewise growth curve modeling to investigate these aims. Supporting the ACM theory, there was significant hierarchical coordination between the systems such that those with low HRV had higher sAA and cortisol reactivity and those with high HRV had low-to-moderate sAA and cortisol responsivity. Our novel results reveal the necessity of studying multisystem dynamics in an integrative fashion to uncover the true mechanisms of stress response and regulation during development. Additionally, our findings support the existence of characteristic stress response profiles as predicted by the ACM model.

Maternal Sensitivity Modulates Child's Parasympathetic Mode and Buffers Sympathetic Activity in a Free Play Situation

Background

Behavioral and physiological (self-)regulation in early life is crucial for the understanding of childhood development and adjustment. The autonomic nervous system (ANS) is a main player in the regulative system and should therefore be modulated by the quality of interactive behavior of the caregiver. We experimentally investigated the ANS response of 18–36-month-old children in response to the quality of maternal behavior during a mother–child-interacting paradigm.

Method

Eighty mothers and their children came to our laboratory and took part in an experimental paradigm, consisting of three episodes: a resting phase (E1), a structured play phase (E2), and a free play situation (E3) between mothers and their child. Children’s and mother’s heart rate (HR), the sympathetic nervous system (SNS) activity via the pre-ejection period (PEP) and the left ventricular ejection time (LVET), and the parasympathetic nervous system (PNS) activity via the respiratory sinus arrhythmia (RSA) were continuously measured by an electrocardiogram. Maternal sensitivity of interactive behavior was assessed by using the Emotional Availability (EA) Scales.

Results

Children of mothers with insensitive behavior had a significantly lower RSA at baseline, showed a lack of RSA withdrawal during structured and free play, and had shorter LVET across all episodes compared to children of sensitive mothers.

Conclusion

Our findings depict the influence of low-quality maternal interaction on the child’s ANS regulation, in calm and more stressful play situations. The overall higher SNS mode with impaired PNS reactivity may negatively influence child’s ANS homoeostasis, which may result in a long-term impact on mental and physical wellbeing. Further, the maternal sensitivity may function as a buffer for the stress response of their child. These results could serve as a basis for the development of appropriate psychoeducational programs for mothers of low sensitivity in their interaction with the child.

Improvement in parasympathetic regulation is associated with engagement in classroom activity in primary school children experiencing poor classroom climate

BACKGROUND

Self-regulation promotes engagement within the classroom. At a physiological level, a good indicator of the ability of the system to self-regulate is cardiac vagal tone (CVT).

AIMS

The present study aims to assess children's change over time (1 year) in their parasympathetic regulation (by way of CVT) in response to a social and cognitive stressor. Moreover, it addresses whether, if present, this change over time in regulation influences students' engagement in classroom activities while also accounting for classroom climate.

SAMPLE

Forty-nine second graders were assessed at two time points: November 2018 (T1) and 1 year later in 2019 (T2).

METHODS

Children's CVT was registered at rest and while performing a stressful task during which they were asked to cognitively perform while being socially evaluated. Children were also interviewed on how much they feel engaged in classroom activities and their perceptions of classroom climate.

RESULTS

A repeated measures analysis of variance including 2 Time Points ×2 Phases of CVT Registration (baseline and during the stressful task) revealed a significant decrease in cardiac vagal activity from baseline to the task at T1, indicating that initially most children were not able to self-regulate and gave way to a stress response when facing the stressful task. The pattern changed at T2 when an active regulation took place signalled by an increase in CVT from baseline to the stressful task. Data analysis also revealed that among children who perceived a poorer classroom climate, the display of greater parasympathetic regulation over time was linked with higher active engagement in classroom activities.

CONCLUSIONS

Growth in physiological regulation in response to a challenging task is associated with better engagement in classroom activities. Interventions and educational practice promoting the development of self-regulation strategies are recommended.

Maternal respiratory sinus arrhythmia contextualizes the relation between maternal anxiety and overprotective parenting

This current study examined maternal characteristics that predict the use of overprotective parenting in mothers of toddlers. Maternal respiratory sinus arrhythmia (RSA) reactivity was tested as a moderator of the relation between maternal anxiety and overprotective parentig. Mothers (n = 151) and their 2-year-old toddlers participated in a laboratory visit and returned for a follow-up visit 1 year later. At child age 2, mothers reported their own anxiety. Mothers' RSA reactivity was measured between a resting baseline and a standardized laboratory task, and overprotective parenting was observed in that task. Toddler fearful temperament (FT) was observed in a separate standardized task as well as reported by mothers. At child age 3, mothers' overprotective parenting behaviors were observed according to the same procedures so change from age 2 could be measured. Results revealed that maternal anxiety and maternal RSA at age 2 interacted to predict relative increases in overprotective parenting behaviors at age 3. At low levels of RSA reactivity, reflecting RSA suppression, maternal anxiety predicted lower levels of overprotective parenting. At high levels of RSA reactivity, reflecting RSA augmentation, maternal anxiety predicted higher levels of overprotective parenting. Our results suggest that RSA suppression may protect mothers with anxiety symptoms from engaging in overprotective parenting, whereas RSA augmentation may put mothers with anxiety symptoms at risk for engaging in overprotective parenting. Findings indicate that the interaction of multiple parental traits should be considered when working with parents and families on parenting behavior. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Integrating dynamic and developmental time scales: Emotion-specific autonomic coordination predicts baseline functioning over time

Autonomic nervous system activity flexibly shifts and modulates behavior at multiple time scales, with some work suggesting that patterns of short-term reactivity contribute to long-term developmental change. However, previous work has largely considered sympathetic and parasympathetic systems independently, even though both systems contribute dynamically to the regulation of physiological arousal. Using physiological data obtained from 313 children in kindergarten, 1st, and 2nd grade we examined whether within-person autonomic coordination during an emotion-inducing film task in kindergarten was associated with developmental change in resting autonomic activity. On average, these kindergarteners exhibited reciprocal coordination during the approach-oriented emotion (angry, happy) condition and a lack of coordination during the avoidance-oriented emotion (fear, sad) condition. Alignment with these patterns was associated with more typical autonomic development, specifically an increase in resting respiratory sinus arrhythmia (RSA) and a decrease in resting skin conductance (SCR) from kindergarten to 2nd grade; while lack of coordination during the approach condition was associated with a relatively delayed increase in resting RSA and a steeper decline in SCR, and reciprocal coordination during the avoidance condition was associated with a lack of RSA increase. Findings highlight the need for additional consideration of how moment-to-moment dynamics of autonomic coordination influence longer-term development, and suggest that early patterns of atypical arousal may portend dysregulation of developing physiological systems.

Conduct problems among children in low-income, urban neighborhoods: A developmental psychopathology- and RDoC-informed approach

Conduct problems are associated with numerous negative long-term psychosocial sequelae and are among the most frequent referrals for children's mental health services. Youth residing in low-income, urban communities are at increased risk for conduct problems, but not all youth in these environments develop conduct problems, suggesting heterogeneity in risk and resilience processes and developmental pathways. The present study used a developmental psychopathology- and Research Domain Criteria (RDoC)-informed approach for conceptualizing risk and resilience for conduct problems among children from low-income, urban neighborhoods. Participants were 104 children (M = 9.93 ± 1.22 years; 50% male; 96% African American, 4% Latinx). We assessed four constructs reflecting cognitive and neurobiological processes associated with conduct problems using multiple levels of analysis and informants: autonomic nervous system reactivity, limbic system/orbitofrontal cortical functioning, dorsolateral prefrontal cortical functioning, and conduct problems. Latent profile analysis identified four profiles: typically developing (TD, n = 34); teacher-reported conduct problems (TCP, n = 14); emotion processing (EP, n = 27); and emotion expression recognition (EER, n = 29). External validation analyses demonstrated that profiles differed on various indices of conduct problems in expected ways. The EP profile exhibited lower levels of emotional lability and callous–unemotional behaviors, and higher levels of prosocial behavior. The TD profile demonstrated elevated emotional lability. Implications for etiological and intervention models are presented.

Long-Term Outcomes after Neonatal Hypoxic-Ischemic Encephalopathy in the Era of Therapeutic Hypothermia: A Longitudinal, Prospective, Multicenter Case-Control Study in Children without Overt Brain Damage

Background. Data on long-term outcomes in the era before therapeutic hypothermia (TH) showed a higher incidence of cognitive problems. Since the introduction of TH, data on its results are limited. Methods. Our sample population consisted of 40 children with a history of hypoxic-ischemic encephalopathy (HIE) treated with TH, with an average age of 6.25 years (range 5.5, 7.33), 24 (60%) males; and 33 peers with an average age of 8.8 years (6.08, 9.41), 17 (51%) males. Long-term follow-up data belong to two centers in Padova and Torino. We measured general intelligence (WPPSI-III or WISC-IV) and neuropsychological functioning (language, attention, memory, executive functions, social skills, visual motor abilities). We also administered questionnaires to their parents on the children’s psychopathological profiles and parental stress. Results. We found differences between groups in several cognitive and neuropsychological domains: intelligence, visuomotor skills, executive functions, and attention. Interestingly, IQ test results effectively differentiated between the groups (HIE vs. controls). Furthermore, the incidence of psychopathology appears to be significantly higher in children with HIE (35%) than in control peers (12%). Conclusions. Our study supports previous findings on a higher incidence of neuropsychological, cognitive, and psychopathological sequelae after HIE treated with TH. As hypothesized, TH does not appear to ameliorate the outcome after neonatal HIE in those children who survive without major sequelae.

Maternal dynamic respiratory sinus arrhythmia during toddlers' interactions with novelty

Maternal psychophysiological responses to toddlers' distress to novelty may have important implications for parenting during early childhood that are relevant to children's eventual development of social withdrawal and anxiety. Likely, these responses depend on intrapersonal, interpersonal, and contextual factors. The current study investigated the time course of respiratory sinus arrhythmia (RSA) across two laboratory novelty episodes, one low threat and one moderate threat, in 120 mothers of 2-year-old toddlers. Growth models tested context differences in and correlates of dynamic patterns of RSA. Dynamic patterns differed between tasks and according to mothers' perceptions of and distress about toddler shyness. Thus, changes in mothers' RSA across toddlers' interactions with novelty seem to depend on the context as well as how mothers perceive and respond to their toddlers' shyness.

Maternal expressions of positive emotion for children predicts children's respiratory sinus arrhythmia surrounding stress

The aim of this study is to assess whether positive emotional exchanges (i.e., emotion coregulation) within the mother-child dyad play a protective role in children's physiological response to a distressing task. Specifically, we test whether positive emotion coregulation among mothers and their preschool-aged children is associated with children's respiratory sinus arrhythmia (RSA) at baseline, during, and following a frustration task. One hundred Singaporean mother-child dyads (M_childage  = 3.5 years) participated in a standardized "Laughing Task" in which positive emotional constructs were measured. Children also participated in a frustration task while RSA was continuously monitored. Hierarchical linear regressions revealed that greater maternal positive emotional responses to children were associated with child RSA at baseline and in recovery from frustration, but not during frustration. These findings have implications for the important role that positive emotion responsivity from mothers may play in children's developing autonomic response systems, and underscore the need for longitudinal work on this topic.

The longitudinal negative impact of early stressful events on emotional and physical well-being: The buffering role of cardiac vagal development

Early stressful events negatively affect emotional and physical well-being. Cardiac vagal tone (CVT), which is associated with better emotional and physical well-being, usually gradually increase in early childhood. Nonetheless, children's CVT developmental trajectories are greatly variable, such that CVT can increase or decrease across the years. The present study examines the longitudinal effects of early stressful events and the role of 4 years CVT developmental trajectory on children's emotional and physical well-being. Forty-two 4-year-old children were enrolled. Number of stressful events and resting electrocardiogram (ECG) were collected at T1. ECG was registered again after one (T2), two (T3) and three (T4) years. Children's emotional and physical well-being were assessed at T4 through the Child Health and Illness Profile - Child Edition (CHIP-CE). CVT development was calculated as the angular coefficient, reflecting the developmental trajectory of CVT across the four timepoints. Results yielded that higher experienced stressful events predicted poorer emotional and physical well-being after 4 years. The interaction between the number of stressful events and CVT development emerged on physical well-being. Early stressful events negatively affect long-term children's emotional and physical well-being while a positive CVT development seems to mitigate the negative effects of early stressful events on physical well-being.

Respiratory sinus arrhythmia as a dyadic protective factor in the transition to parenthood

Considerable heterogeneity has been observed in couples' adjustment to the transition to parenthood (TTP). One potential yet understudied predictor of emotional adjustment to the TTP is the new parents' capacity for regulation. A widely accepted biological marker of this capacity is respiratory sinus arrhythmia (RSA), which is closely tied to parasympathetic activation. In the present work, we sought to examine the role of tonic RSA and RSA reactivity as possible protective dyadic factors in the TTP. As part of a larger study, we recruited a sample (N = 100) of TTP couples. At 15 weeks postpartum, the couples took part in a lab session during which their RSA was assessed both at rest (tonic RSA) and during four affiliative dyadic interactions (RSA reactivity). Following this session, couples completed daily diaries over a period of 3 weeks, reporting their daily levels of negative affect and stress. A Multivariate Actor Partner Interdependence Model was used to examine the extent to which each partner's RSA predicted their own and their partner's negative affect (NA) level, as well as NA stress-reactivity (i.e., the strength of the within-person stress-affect association). New mothers' tonic RSA predicted their own lower NA level and NA stress-reactivity; both their tonic RSA and RSA reactivity predicted their (male) partners' lower NA level; and finally, new fathers' tonic RSA and RSA reactivity predicted their (female) partners' lower NA stress-reactivity. These results suggest that RSA may serve as a personal and dyadic protective factor.

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.

Biological sensitivity to context: A test of the hypothesized U-shaped relation between early adversity and stress responsivity

We conducted signal detection analyses to test for curvilinear, U-shaped relations between early experiences of adversity and heightened physiological responses to challenge, as proposed by biological sensitivity to context theory. Based on analysis of an ethnically diverse sample of 338 kindergarten children (4-6 years old) and their families, we identified levels and types of adversity that, singly and interactively, predicted high (top 25%) and low (bottom 25%) rates of stress reactivity. The results offered support for the hypothesized U-shaped curve and conceptually replicated and extended the work of Ellis, Essex, and Boyce (2005). Across both sympathetic and adrenocortical systems, a disproportionate number of children growing up under conditions characterized by either low or high adversity (as indexed by restrictive parenting, family stress, and family economic condition) displayed heightened stress reactivity, compared with peers growing up under conditions of moderate adversity. Finally, as hypothesized by the adaptive calibration model, a disproportionate number of children who experienced exceptionally stressful family conditions displayed blunted cortisol reactivity to stress.

Associations between classroom climate and children's externalizing symptoms: The moderating effect of kindergarten children's parasympathetic reactivity

Classrooms are key social settings that impact children's mental health, though individual differences in physiological reactivity may render children more or less susceptible to classroom environments. In a diverse sample of children from 19 kindergarten classrooms (N = 338, 48% female, M age = 5.32 years), we examined whether children's parasympathetic reactivity moderated the association between classroom climate and externalizing symptoms. Independent observers coded teachers' use of child-centered and teacher-directed instructional practices across classroom social and management domains. Children's respiratory sinus arrhythmia reactivity to challenge tasks was assessed in fall and a multi-informant measure of externalizing was collected in fall and spring. Both the social and the management domains of classroom climate significantly interacted with children's respiratory sinus arrhythmia reactivity to predict spring externalizing symptoms, controlling for fall symptoms. For more reactive children, as classrooms shifted toward greater proportional use of child-centered methods, externalizing symptoms declined, whereas greater use of teacher-dominated practices was associated with increased symptoms. Conversely, among less reactive children, exposure to more teacher-dominated classroom management practices was associated with lower externalizing. Consistent with the theory of biological sensitivity to context, considering variability in children's physiological reactivity aids understanding of the salience of the classroom environment for children's mental health.

Callous-unemotional traits and fearlessness: A cardiovascular psychophysiological perspective in two adolescent samples using virtual reality

There has been a longstanding debate about the link between callous-unemotional traits and fearlessness. However, biological evidence for a relationship in adolescents is lacking. Using two adolescent samples, we measured emotional reactivity and cardiac measures of sympathetic (pre-ejection period) and parasympathetic (respiratory sinus arrhythmia) reactivity during 3D TV and virtual reality fear induction. Study 1 included 62 community adolescents from a stratified sample. Study 2 included 60 adolescents from Emotional and Behavioral Difficulties schools. Results were consistent across both studies. Adolescents with high callous-unemotional traits showed coactivation of the sympathetic and parasympathetic nervous system. Consistent with these results, youths with callous-unemotional traits self-reported that they felt more in control after the fear induction. Thus, in both samples, youth with callous-unemotional traits displayed a physiological and emotional profile suggesting they maintained control during fear induction. Therefore, it is proposed here that a shift in thinking of youth with callous-unemotional traits as fearless to youth with callous-unemotional traits are better able to manage fearful situations, may be more appropriate.

Towards an understanding of neurophysiological self-regulation in early childhood: A heuristic and a new approach

Self-regulation in early childhood encompasses both "top down," volitional processes, as well as the "bottom up" activity of three neurophysiological systems: the parasympathetic nervous system (PNS), the sympathetic nervous system (SNS), and the hypothalamic-pituitary-adrenal (HPA) axis. In this paper we briefly review the structure, function, and early development of each of these systems and then explain why neurophysiological self-regulation is most accurately defined as a function of their joint activity. We note that while there are a number of predictive models that employ this definition, the field would benefit from a straightforward heuristic and aligned methods of visualization and analysis. We then present one such heuristic, which we call neurophysiological space, and outline how it may facilitate a new, collaborative approach to building a better understanding of self-regulation in early childhood. We conclude with a presentation of early education as one setting in which our heuristic and methods could be applied.

An autonomic nervous system context of harsh parenting and youth aggression versus delinquency

Harsh parenting is a significant predictor of youth aggression and delinquency. However, not every child exposed to adverse parenting develops such problem behaviors. Recent developmental evolutionary models suggest that variability in stress response reactivity to parenting, reflected by autonomic nervous system (ANS) functioning, may affect the impact of adverse parenting on youth behavioral adjustment. The aim of the present study was to investigate whether the parasympathetic and sympathetic branches of the ANS moderate the association between parenting and aggressive and delinquent behaviors. The study sample included low-income, ethnically diverse preadolescents (M = 10.28 years old; N = 101) and their caregivers. Direct effects were found from basal RSA to delinquent behaviors. In addition, harsh parenting predicted increased youths' aggressive and delinquent behaviors in the context of high RSA withdrawal and increased youths' delinquent behaviors in the context of shortened basal PEP. Implications for prevention and intervention are discussed.

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.

Sustained Attention and Individual Differences in Adolescents' Mood and Physiological Reactivity to Stress

Biased attention to sad faces is associated with depression in adults and is hypothesized to increase depression risk specifically in the presence, but not absence, of stress by modulating stress reactivity. However, few studies have tested this hypothesis, and no studies have examined the relation between attentional biases and stress reactivity during adolescence, despite evidence that this developmental window is marked by changes in depression risk, stress, and the function of attention. Seeking to address these limitations, the current study examined the impact of adolescents' sustained attention to facial displays of emotion on individual differences in both mood reactivity to real-world stress and physiological (i.e., respiratory sinus arrhythmia [RSA]) reactivity to a laboratory-based stressor. Consistent with vulnerability-stress models of attention, greater sustained attention to sad faces was associated with greater depressive reactions to real-world stress. In addition, there was preliminary evidence from exploratory analyses that the impact of sustained attention on mood and/or physiological reactivity may be moderated by adolescents' age and sex such that relations are stronger for older adolescents and girls. The results of this study contribute to the current body of research on the role of attention in stress reactivity and depression risk and highlight the importance of considering age differences when examining these relations.

Culture and stress biology in immigrant youth from the prenatal period to adolescence: A systematic review

Immigration patterns over the last two decades have changed the demographic composition of the United States; children are growing up in an increasingly multicultural environment. Immigrant youth may face culture-related stressors and leverage culture-related strengths across development that may influence their mental and physical health. Responses to early life stressors may differ across children at the level of stress biology, which can affect how they handle cultural challenges. However, there is limited research on culture and stress biology, which may be a mediator or moderator of culture's effects on immigrant youth. The aim of the present article is to systematically review research that examines the roles of both culture and stress biology from the prenatal period to adolescence in immigrant youth. Specifically, we review articles that examine how stress-sensitive biological systems (hypothalamic pituitary adrenal axis and the autonomic nervous system) and culture-related constructs have been modeled together in immigrant youth. Based on these findings, we note remaining questions and recommendations for future research in integrating measures of cultural processes and stress biology in children.

Autonomic functioning among cocaine-exposed kindergarten-aged children: Examination of child sex and caregiving environmental risk as potential moderators

The purpose of this study was to examine the hypothesis that child sex moderates the association between prenatal cocaine exposure (PCE) and autonomic functioning as well as to examine the role that caregiving environmental risk played in sex differences in autonomic functioning among exposed children. Measures of the parasympathetic nervous system (indexed by respiratory sinus arrhythmia [RSA]) and the sympathetic nervous system (indexed by skin conductance level [SCL]) were obtained from 146 (75 cocaine-exposed, 38 male; and 71 nonexposed, 36 male) children during baseline and a task designed to elicit negative affect (NA). We also examined the role of caregiving environmental risk as a moderator of the association between PCE and autonomic functioning separately for boys and girls. PCE boys had a significantly higher baseline RSA and lower baseline SCL than PCE girls or nonexposed children. Environmental risk also moderated the association between PCE and baseline RSA for boys, but not girls, such that boys with PCE and high environmental risk had the highest baseline RSA. These findings indicate that exposed boys had significantly lower levels of sympathetic activation while at rest. However, for autonomic reactivity, the exposed girls had a larger change in both RSA and SCL relative to nonexposed girls while exposed boys had significantly smaller increases in SCL during environmental challenge. Finally, girls with both PCE and high environmental risk had the highest levels of parasympathetic reactivity during challenge. These results underscore the importance of examining sex differences and considering comorbid environmental risk factors when examining developmental outcomes in cocaine-exposed children and highlight the complexity involved with understanding individual differences in cocaine-exposed populations.

Meta-analysis of the effectiveness of the Trier Social Stress Test in eliciting physiological stress responses in children and adolescents

The Trier Social Stress Test (TSST) is known to reliably induce physiological stress responses in adult samples. Less is known about its effectiveness to elicit these responses in youth samples. We performed a meta-analysis of stress responses to the TSST in youth participants. Fifty-seven studies were included representing 5026 youth participants. Results indicated that the TSST was effective at eliciting stress responses for salivary cortisol (sCort; effect size [ES] = 0.47, p = 0.006), heart rate (HR; ES = 0.89, p < 0.001), pre-ejection period (PEP; ES = -0.37, p < 0.001), heart rate variability (HRV; ES = -0.33, p = 0.028), and systolic blood pressure (ES = 1.17, p < 0.001), as well as negative affect (ES = 0.57, p = 0.004) and subjective anxiety (ES = 0.80, p = 0.004) in youth samples. Cardiac output (ES = 0.15, p = 0.164), respiratory sinus arrhythmia (ES = -0.10, p = 0.064), and diastolic blood pressure (ES = 2.36, p = 0.072) did not reach statistical significance. Overall, effect sizes for the TSST varied based on the physiological marker used. In addition, several physiological markers demonstrated variance in reactivity by youth age (sCort, HR, HRV, and PEP), gender (sCort), type of sample (i.e., clinical versus community sample; sCort and HR), duration of TSST (sCort, HR, HRV, negative affect, and subjective anxiety), number of judges present in TSST (HR and subjective anxiety), gender of judges (sCort), and time of day the marker was assessed (morning versus afternoon/evening; sCort). Overall, the findings provide support for the validity of the TSST as a psychosocial stressor for inducing physiological and psychological stress responses in children and adolescents, but also highlight that some markers may capture the stress response more effectively than others.

Evidence for discrete profiles of children's physiological activity across three neurobiological system and their transitions over time

The conceptualization of stress-responsive physiological systems as operating in an integrated manner is evident in several theoretical models of cross-system functioning. However, limited empirical research has modeled the complexity of multisystem activity. Moreover few studies have explored developmentally regulated changes in multisystem activity during early childhood when plasticity is particularly pronounced. The current study used latent profile analysis (LPA) to evaluate multisystem activity during fall and spring of children's transition to kindergarten in three biological systems: the parasympathetic nervous system (PNS), sympathetic nervous system (SNS), and hypothalamic pituitary adrenal (HPA) axis. Latent transition analysis (LTA) was then used to examine the stability of profile classification across time. Across both timepoints, three distinct profiles of multisystem activity emerged. One profile was characterized by heightened HPA axis activity (HPA Axis Responders), a second profile was characterized by moderate, typically adaptive patterns across the PNS, SNS, and HPA axis (Active Copers/Mobilizers), and a third profile was characterized by heightened baseline activity, particularly in the PNS and SNS (Anticipatory Arousal/ANS Responders). LTA of fall-to-spring profile classifications indicated higher probabilities that children remained in the same profile over time compared to probabilities of profile changes, suggesting stability in certain patterns of cross-system responsivity. Patterns of profile stability and change were associated with socioemotional outcomes at the end of the school year. Findings highlight the utility of LPA and LTA to detect meaningful patterns of complex multisystem physiological activity across three systems and their associations with early adjustment during an important developmental transition.

Developmental patterns of respiratory sinus arrhythmia from toddlerhood to adolescence

Parasympathetic nervous system functioning as indexed by respiratory sinus arrhythmia (RSA) is widely used as a measure of physiological regulation. We examined developmental patterns of children's resting RSA and RSA reactivity from 2 to 15 years of age, a period of time that is marked by considerable advances in children's regulatory abilities. Physiological data were collected from a community sample of 270 children (116 males) during a resting period and during a frustration laboratory task when the children were 2, 4, 5, 7, 10, and 15 years old. We examined both stability and continuity in resting RSA and RSA reactivity across time. We found stability in resting RSA but not RSA reactivity from toddlerhood to adolescence. Separate multilevel models were used to examine changes in resting RSA and RSA reactivity from Age 2 to Age 15. The rate of change in resting RSA slowed from Age 2 to Age 15 with a plateau around Age 10. A splined growth model indicated that the rate of RSA reactivity increased from Age 2 to Age 7 and a modest slowing and leveling off from Age 7 to Age 15. Understanding the developmental characteristics of RSA across childhood and adolescence is important to understanding the larger constructs of self- and emotion regulation. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Cortical and affective regulation of autonomic coordination

Although anatomical research clearly demonstrates the ability of the sympathetic and parasympathetic branches of the autonomic nervous system to independently influence cardiac function, little research has examined whether coordinated activation is typical or whether the extent of autonomic coordination is situationally dependent. This study examines the extent of coordination between sympathetic (cardiac pre-ejection period: PEP) and parasympathetic (respiratory sinus arrhythmia: RSA) influences on the cardiac function to determine whether coordination is a trait-like between-person characteristic or a state-varying within-person phenomenon, and if so, whether variability in autonomic coordination is modulated by cognitive (P3b amplitude) or affective state. Kindergarten-aged children (n = 257) completed a go/no-go task administered in blocks designed to induce affective states through the delivery of reward (Blocks 1 and 3) and frustration (Block 2). Results from multilevel models that allowed for the simultaneous examination of between-person and within-person associations in the repeated measures data suggested that (a) children with higher overall RSA also tended to have higher overall PEP; (b) at within-person level, RSA and PEP tended to be reciprocally coordinated; but that (c) when frustration invokes cognitive disengagement, coordination between parasympathetic and sympathetic systems demonstrate compensatory coordination. These findings highlight the extent to which the coordination of autonomic systems is a dynamic state-like phenomenon rather than a trait-like individual differences characteristic.

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.

Children's physiological reactivity in emotion contexts and prosocial behavior

INTRODUCTION

Building on prior evidence that prosocial behavior is related to the regulation of personal distress in difficult situations, and given that physiological regulation is a central contributor to effective emotion regulation, this investigation evaluated whether and how children's autonomic nervous system (ANS) reactivity during emotion challenges influenced later expressions of prosocial behavior.

METHODS

The current study utilized a diverse sample of school-aged children (N = 169; 47.9% female; 47.3% Latinx) to evaluate relations between children's parasympathetic (i.e., respiratory sinus arrhythmia; RSA) and sympathetic (i.e., pre-ejection period; PEP) reactivity in response to each of three film-elicited emotion challenges (i.e., sadness, happiness, and fear) at age 7 and both observed and parent-reported prosocial behavior one year later.

RESULTS

Children's parasympathetic reactivity to a film eliciting sadness evidenced a nonlinear relation with later prosocial sharing such that children who evidenced either RSA withdrawal or augmentation in response to the sad emotion challenge engaged in higher levels of prosocial behavior than children who evidenced relatively low or absent reactivity. Parasympathetic reactivity to films eliciting happiness or fear was not significantly related to later prosocial behavior. Likewise, children's sympathetic reactivity in response to the emotion challenges did not significantly predict later prosocial behavior.

CONCLUSIONS

These findings provide preliminary support for a nonlinear association between children's parasympathetic emotion reactivity and later prosocial behavior, and suggest that children's ANS regulation in sad emotion contexts may be particularly important for understanding prosocial development.

Young Children's Physiological Reactivity during Memory Recall: Associations with Posttraumatic Stress and Parent Physiological Synchrony

Autonomic reactivity is implicated in stress response and social engagement - both key components of posttraumatic stress disorder (PTSD) - but few studies have examined autonomic reactivity in pediatric samples, and no known studies have examined physiological synchrony among children with PTSD and caregivers. In a sample of 247 young children (94 girls, 153 boys), most (85%) of whom had exposure to trauma and 40% who met criteria for PTSD, we examined children's patterns of respiratory sinus arrhythmia (RSA) at baseline and in response to a memory recall task, as well as correspondence between parents' and children's RSA. Children with PTSD demonstrated significantly higher reactivity than other groups during their recollection of a traumatic memory, but not during other memory tasks. Regarding synchrony, caregivers' and children's RSA were more significantly and positively correlated during the trauma recall task among children who had had exposure to a potentially traumatic event but did not meet PTSD criteria, suggesting physiological synchrony may be protective in contexts of trauma. Overall, findings demonstrate physiological reactivity differences among young children with PTSD. While more work is needed to understand the meaning of parent-child physiological synchrony, these data suggest that children's psychopathology is associated with physiological synchrony processes among young children with exposure to trauma.

The impact of maternal stress on infant alpha-amylase is buffered by high infant regulation and low infant negative reactivity

This study examined the main and interactive effects of maternal perceived stress and infant temperament-surgency, negative affectivity, and orienting/regulation-on infant salivary alpha-amylase (sAA) responses to stress. Saliva samples were collected prior to and following two naturalistic stressors: maternal separation conducted at 9 months and blood draw/immunizations conducted at 12 months. sAA area under the curve (AUC) was computed to determine response of the sympathetic nervous system to each stressor. Results revealed significant interactions of maternal stress and infant negative affectivity and orienting/regulation with sAA AUC. Relations between maternal stress and infant sAA AUC were stronger among infants with higher levels of negative affectivity and lower levels of orienting/regulation. These results highlight the need to examine both infant characteristics and environmental factors when investigating the development of stress response systems.

Children's stress regulation mediates the association between prenatal maternal mood and child executive functions for boys, but not girls

Prenatal exposure to maternal mood disturbances shapes children's cognitive development reflected in the critical construct of executive functions (EFs). Little is known, however, about underlying mechanisms. By examining cortisol responses in both everyday and lab challenge settings, we tested whether the child/offspring hypothalamic-pituitary-adrenal axis mediates effects of prenatal maternal mood on child EFs at age 6. In 107 Canadian children born to women with a wide range of anxious and depressive symptoms during pregnancy, we found that in boys but not girls, depressed and/or anxious prenatal maternal mood is associated with heightened diurnal cortisol levels in everyday settings, as well as heightened cortisol reactivity to a lab challenge and that this heightened reactivity was associated with poorer EFs. Among boys we also observed that cortisol reactivity but not diurnal cortisol mediated the association between depressed and/or anxious prenatal maternal mood and EFs. Depressed and/or anxious prenatal maternal mood was related to child EFs for both girls and boys. To our knowledge, this is the first study to demonstrate a mediating role for child stress regulation in the association between prenatal maternal stress-related mood disturbances and child EFs, providing evidence of a mechanism contributing to fetal programming of cognition.

Age-Adapted Stress Task in Preschoolers Does not Lead to Uniform Stress Responses

Acute stress response measures serve as an indicator of physiological functioning, but have previously led to contradictory results in young children due to age-related cortisol hypo-responsivity and methodological inconsistencies in assessment. The aim of this study was to investigate stress responses during a validated age-adapted socio-evaluative stress task in children aged 2-6 years in a child care environment and to detect socio-demographic, task- and child-related characteristics of stress responses. Stress responses were assessed in 323 children for salivary cortisol and salivary alpha amylase (sAA), and in 328 children for changes in heart rate variability (HRV). These data were then associated with socio-demographic (e.g. SES), task-related (e.g. task length) and child-related characteristics (e.g. self-regulation) of stress responses using multilevel models. Analyses revealed elevated sympathetic reactivity (sAA: Coeff=0.053, p=0.004) and reduced HRV (Coeff=-0.465, p<0.001), but no hypothalamic-pituitary-adrenal (HPA) response (Coeff=0.017, p=0.08) during the stress task. Child's age (Coeff=-5.82, p<0.001) and movement during the task (Coeff=-0.17, p=0.015) were associated with acute cortisol release, while diurnal sAA was associated with acute sAA release (Coeff=0.24, p<0.001). Age (Coeff=-0.15, p=0.006) and duration of the task (Coeff=0.13, p=0.015) were further associated with change of HRV under acute stress condition. Children showed inconsistent stress responses which contradicts the assumption of a parallel activation of both stress systems in a valid stress task for young children and might be explained by a pre-arousal to the task of young children in a child care setting. Further results confirm that child- and task-related conditions need to be considered when assessing stress responses in these young children.

Autonomic nervous system functioning assessed during the Still-Face Paradigm: A meta-analysis and systematic review of methods, approach and findings

Animal and human research suggests that the development of the autonomic nervous system (ANS) is particularly sensitive to early parenting experiences. The Still-Face Paradigm (SFP), one of the most widely used measures to assess infant reactivity and emotional competence, evokes infant self-regulatory responses to parental interaction and disengagement. This systematic review of 33 peer-reviewed studies identifies patterns of parasympathetic (PNS) and sympathetic (SNS) nervous system activity demonstrated by infants under one year of age during the SFP and describes findings within the context of sample demographic characteristics, study methodologies, and analyses conducted. A meta-analysis of a subset of 14 studies with sufficient available respiratory sinus arrhythmia (RSA) data examined whether the SFP reliably elicited PNS withdrawal (RSA decrease) during parental disengagement or PNS recovery (RSA increase) during reunion, and whether results differed by socioeconomic status (SES). Across SES, the meta-analysis confirmed that RSA decreased during the still-face episode and increased during reunion. When studies were stratified by SES, low-SES or high-risk groups also showed RSA decreases during the still face episode but failed to show an increase in RSA during reunion. Few studies have examined SNS activity during the SFP to date, preventing conclusions in that domain. The review also identified multiple qualifications to patterns of SFP ANS findings, including those that differed by ethnicity, infant sex, parental sensitivity, and genetics. Strengths and weaknesses in the extant research that may explain some of the variation in findings across the literature are also discussed, and suggestions for strengthening future research are provided.

Children's biobehavioral reactivity to challenge predicts DNA methylation in adolescence and emerging adulthood

A growing body of research has documented associations between adverse childhood environments and DNA methylation, highlighting epigenetic processes as potential mechanisms through which early external contexts influence health across the life course. The present study tested a complementary hypothesis: indicators of children's early internal, biological, and behavioral responses to stressful challenges may also be linked to stable patterns of DNA methylation later in life. Children's autonomic nervous system reactivity, temperament, and mental health symptoms were prospectively assessed from infancy through early childhood, and principal components analysis (PCA) was applied to derive composites of biological and behavioral reactivity. Buccal epithelial cells were collected from participants at 15 and 18 years of age. Findings revealed an association between early life biobehavioral inhibition/disinhibition and DNA methylation across many genes. Notably, reactive, inhibited children were found to have decreased DNA methylation of the DLX5 and IGF2 genes at both time points, as compared to non‐reactive, disinhibited children. Results of the present study are provisional but suggest that the gene's profile of DNA methylation may constitute a biomarker of normative or potentially pathological differences in reactivity. Overall, findings provide a foundation for future research to explore relations among epigenetic processes and differences in both individual‐level biobehavioral risk and qualities of the early, external childhood environment.

Parental Attachment and Children's Memory for Attachment-Relevant Stories

Despite evidence that parents' attachment is associated with children's memory, less is known about the mechanisms underlying this association or the contexts in which the association is most meaningful. The present study examined whether parents' attachment predicted children's memory for stories about attachment-related topics, whether the cohesiveness of children's stories mediated the association between attachment and memory, and whether the association varied by interview support at retrieval. Five- to 6-year-olds completed attachment-relevant stories while parents provided information about their romantic attachment. Children's stories were coded for cohesiveness. A week later, children's memory for their stories was tested by either a supportive or non-supportive interviewer. When the interview was non-supportive, greater parental avoidance was associated with poorer memory, whereas when the interview was supportive, greater parental avoidance was associated with fewer errors. Findings provide insight into the context under which parents' attachment is most influential in shaping children's memory.