Differentiating challenge reactivity from psychomotor activity in studies of children's psychophysiology: considerations for theory and measurement

Longitudinal associations between maternal harsh parenting and child temperament: The moderating role of children's respiratory sinus arrhythmia

To better understand biology by environment interactions in early temperament, we examined whether children's respiratory sinus arrhythmia (RSA; resting RSA and RSA reactivity) operated as a biological marker of differential susceptibility to maternal harsh parenting in predicting children's temperament. Participants were 133 mother-child dyads (53% male children) from families oversampled for lower income, higher life stress, and child maltreatment risk. Mothers reported harsh parenting at age 3 and children's temperament, including negative affectivity, effortful control, and surgency, at ages 3 and 4. Resting RSA was measured during a 3-min resting task. RSA reactivity was computed as a difference score between a 4-min toy cleanup task and the resting task. Results showed that the interaction between maternal harsh parenting and children's resting RSA significantly predicted negative affectivity, after controlling for sex, household income, and age 3 negative affectivity. Specifically, harsh parenting positively predicted negative affectivity among children with higher, but not lower, resting RSA. Similarly, maternal harsh parenting interacted with children's RSA reactivity to predict negative affectivity after adjusting for controls, such that harsh parenting positively predicted negative affectivity in children with higher, but not lower, RSA reactivity. These findings suggest that higher resting RSA and greater RSA reactivity may operate as markers of increased susceptibility to negative parenting in the development of negative affectivity. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Autonomic brain functioning and age-related health concerns

The autonomic nervous system (ANS) regulates involuntary bodily functions such as blood pressure, heart rate, breathing, and digestion, in addition to controlling motivation and behavior. In older adults, the ANS is dysregulated, which changes the ability of the ANS to respond to physiological signals, regulate cardiovascular autonomic functionality, diminish gastric motility, and exacerbate sleep problems. For example, a decrease in heart rate variability, or the variation in the interval between heartbeats, is one of the most well-known alterations in the ANS associated with health issues, including cardiovascular diseases and cognitive decline. The inability to perform fundamental activities of daily living and compromising the physiological reactivity or motivational responses of older adults to moving toward or away from specific environmental stimuli are significant negative consequences of chronic and geriatric conditions that pose grave threats to autonomy, health, and well-being. The most updated research has investigated the associations between the action responsiveness of older adults and the maintenance of their physiological and physical health or the development of mental and physical health problems. Once autonomic dysfunction may significantly influence the development of different age-related diseases, including ischemic stroke, cardiovascular disease, and autoimmune diseases, this review aimed to assess the relationship between aging and autonomic functions. The review explored how motivational responses, physiological reactivity, cognitive processes, and lifelong developmental changes associated with aging impact the ANS and contribute to the emergence of health problems.

Dimensions of childhood adversity differentially affect autonomic nervous system coordination in response to stress

It is well-established that disrupted autonomic nervous system (ANS) reactivity exacerbates risk for long-term maladjustment following childhood adversity (CA). However, few studies have integrated measures of both the sympathetic (SNS) and parasympathetic (PNS) branches of the ANS, resulting in a unidimensional understanding of ANS functioning as a mechanism of risk. Further, past work has primarily measured CA only at the aggregate level (e.g. "total CA"), necessitating further research to accurately characterize this risk pathway. The present study examines how CA, measured cumulatively and dimensionally (i.e. CA characterized by threat versus deprivation), moderates the association between the SNS and PNS at rest and in response to acute social and nonsocial stressors. Participants included 97 adolescents ages 10-15 (Mage = 12.22, SDage = 1.68) experiencing a range of CA and one accompanying caregiver. Participants completed questionnaires assessing prior CA exposure. SNS and PNS responses were then continuously measured during rest and two stress tasks. First, results indicate a blunting effect of cumulative CA and CA characterized by threat (e.g. physical abuse) on resting SNS activity. Second, in moderation analyses assessing ANS coordination, threat exposure emerged as a significant moderator of the association between SNS and PNS reactivity to social stress. Results suggest that CA characterized by threat may specifically impact physiologic regulation by disrupting the coordination of the two branches of the ANS. Disentangling the independent and concurrent engagement of biological stress response systems following CA remains an important target for research to identify the etiology of aberrant stress reactivity patterns.

Cortisol response marks biological sensitivity to kindergartners' social hierarchies for emerging school engagement

This longitudinal study investigated how kindergartners' position in the classroom social hierarchy and cortisol response relate to their change in school engagement across the first year of kindergarten (N = 332, M = 5.3 years, 51% boys, 41% White, 18% Black). We used naturalistic classroom observations of social hierarchy positions, laboratory-based challenges to elicit salivary cortisol response, and teacher, parent, and child reports of emotional engagement with school. Robust, clustered regression models revealed that in the fall, lower cortisol response (but not social hierarchy position) was associated with greater school engagement. However, by spring, significant interactions emerged. Highly reactive, subordinate children showed increases in school engagement from fall to spring of the kindergarten year, whereas highly reactive, dominant children showed decreases in school engagement. This is some of the first evidence that higher cortisol response marks biological sensitivity to early peer-based social contexts.

Association Between Measures Derived From Children's Primary Exfoliated Teeth and Psychopathology Symptoms: Results From a Community-Based Study

Mental disorders are among the most disabling health conditions globally. However, there remains a lack of valid, reliable, noninvasive, and inexpensive biomarkers to identify (at an early age) people who are at the greatest risk of experiencing a future mental health condition. Exfoliated primary teeth, when used in combination with established and emerging tools (e.g., family history, imaging, genetics, epigenetics), may provide important additional insights about vulnerability to mental illness. Teeth are especially promising because they develop in parallel with the brain and maintain a permanent record of environmental insults occurring during prenatal and perinatal development. Despite their potential, few empirical studies have investigated features of exfoliated teeth in relation to mental health. Here, we used micro-CT imaging to test the hypothesis that measures derived from exfoliated primary incisors associated with psychopathology symptoms in a community-based sample of children (n = 37). We found that enamel volume (β = −0.77, 95% CI, −1.35 to −0.18, P = 0.01) had large negative associations with internalizing symptoms, and enamel mineral density (β = 0.77, 95% CI, 0.18–1.35, P = 0.01) had large positive associations with internalizing behavioral symptoms, even after stringent control for multiple testing. Pulp volume (β = −0.50, 95% CI, −0.90 to −0.09, P = 0.02) had a moderately-large negative association with externalizing behavioral symptoms, though these associations did not survive multiple testing correction. These results support the ongoing investigation of teeth as potential novel biomarkers of mental health risk.

Developmental Consequences of Early Life Stress on Risk for Psychopathology: Longitudinal Associations with Children's Multisystem Physiological Regulation and Executive Functioning

The etiology of psychopathology is multifaceted and warrants consideration of factors at multiple levels and across developmental time. Although experiences of adversity in early life have been associated with increased risk of developing psychopathology, pathways toward maladaptation or resilience are complex and depend upon a variety of factors, including individuals' physiological regulation and cognitive functioning. Therefore, in a longitudinal cohort of 113 mother-child dyads, we explored associations from early adverse experiences to physiological co-regulation across multiple systems and subsequent variations in executive functioning. Latent profile analysis derived multisystem profiles based on children's heart rate, respiratory sinus arrhythmia, pre-ejection period, and cortisol measured during periods of rest and reactivity throughout a developmentally challenging protocol. Three distinct profiles of multisystem regulation emerged: heightened multisystem baseline activity (Anticipatory Arousal/ANS Responder), typically adaptive patterns across all systems (Active Copers/Mobilizers) and heightened HPA axis activity (HPA Axis Responders). Path models revealed that children exposed to adversity before 18-months were more likely to evidence an Anticipatory Arousal/ANS Responders response at 36-months, and children in this profile had lower executive functioning scores than the Active Copers/Mobilizers. In sum, these findings provide important information about potential physiological associations linking early adversity to variations in children's task-based executive functioning.

Parental history of childhood maltreatment and child average RSA shape parent-child RSA synchrony

We examined whether dynamic parent-child RSA synchrony varied by individual differences in child average RSA and parental history of childhood maltreatment (CM), which has been linked to parental behavioral and physiological dysregulation. We also examined whether RSA synchrony was curvilinear, reflecting homeostatic regulation. Synchrony was defined as the dynamic association between parent and child RSA reactivity (change relative to their own mean) within epoch across a challenging task. Eighty-three mother-preschooler and 61 father-preschooler dyads participated. State-trait modeling showed that RSA synchrony was curvilinear such that significant relations were only found at lower and higher child reactivity. Children's higher task average RSA predicted maternal RSA augmentation and lower task average RSA predicted maternal RSA withdrawal, regardless of whether child reactivity in the moment was low or high, suggesting individual differences in child regulatory capacity were associated with dynamic maternal reactivity. When maternal CM history and child average RSA were both higher, mothers showed RSA augmentation. Father-child synchrony was not moderated by child average RSA but greater paternal CM history predicted fathers' greater RSA withdrawal regardless of whether child RSA reactivity was low or high. Findings offer novel insights into the nature and meaning of RSA synchrony with parents at risk.

Physiological responses to a school task: The role of student-teacher relationships and students' emotional appraisal

BACKGROUND

To be successful, students must learn to deal with socially and cognitively demanding tasks. Much remains unknown about the effects of previous classroom experiences and of students' emotional appraisal of a task on their physiological adaptive responses to it.

AIMS

To investigate how children's physiological response to a social and cognitive task would be directly and interactively influenced by the perceived student-teacher relationship and by children's emotional appraisal of what reaction they expect to have while completing the task.

METHODS

One hundred and sixteen second and third graders took part in the study. Children completed a cognitive and social stress task. Before the task, they were interviewed on their emotional appraisal of the task and on student-teacher relationships. Children's cardiac activity was registered at rest and during the task to measure physiological activation (heart rate) and self-regulation (heart rate variability).

RESULTS

Heart rate variability during the task was positively correlated with the appraised emotional valence of the task and of being observed while doing it. Regression analyses showed that children's physiological self-regulation during the task was affected by the interaction between student-teacher relationships and appraised emotional valence of being observed. Only among children who had experienced negative student-teacher relationships, an active physiological self-regulation was observed in response to the task when they expected it to be positive compared to when they perceived it as negative.

CONCLUSIONS

Children's emotional appraisal of tasks and the quality of student-teacher relationships are important to promote a functional physiological response of self-regulation that underlies academic functioning and well-being at school.

Interpretation biases and depressive symptoms among anxiety-disordered children: The role of individual differences in respiratory sinus arrhythmia

Individual differences in interpretation biases-the tendency to interpret ambiguous stimuli as threatening-partially explain the presence of comorbid depressive symptoms among anxious youth. Increasing efforts have examined physiological processes that influence the association between interpretation biases and depressive symptoms in this population, and potential gender differences in this relationship. This study examined the moderating role of respiratory sinus arrhythmia (RSA) suppression (i.e., decrease from baseline)-an index of parasympathetic nervous system reactivity-in the association between interpretation biases and depressive symptoms in clinically anxious youth. One-hundred-and-five clinically anxious children (Mage  = 10.09 years, SD = 1.22; 56.7% female; 61.9% racial/ethnic minority) completed measures of self-reported and behaviorally indexed interpretation biases, reported anxiety/depression symptom severity, and participated in a speech task. RSA suppression during the task moderated the association between interpretation biases and depressive symptom severity in the total sample. Separate exploratory moderation analyses were conducted among girls and boys. Among girls, RSA suppression moderated the association between behaviorally indexed interpretation biases and depressive symptoms, and marginally moderated (p = .067) the association between self-reported interpretation biases and depressive symptoms. Among boys, RSA suppression was not a significant moderator. These findings may help identify clinically anxious youth most at-risk for comorbid depressive symptoms.

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.

Physiological measurement of emotion from infancy to preschool: A systematic review and meta-analysis

INTRODUCTION

Emotion regulation, the ability to regulate emotional responses to environmental stimuli, develops in the first years of life and plays an important role in the development of personality, social competence, and behavior. Substantial literature suggests a relationship between emotion regulation and cardiac physiology; specifically, heart rate changes in response to positive or negative emotion-eliciting stimuli.

METHOD

This systematic review and meta-analysis provide an in-depth examination of research that has measured physiological responding during emotional-evoking tasks in children from birth to 4 years of age.

RESULTS

The review had three main findings. First, meta-regressions resulted in an age-related decrease in baseline and task-related heart rate (HR) and increases in baseline and task-related respiratory sinus arrhythmia (RSA). Second, meta-analyses suggest task-related increases in HR and decreases in RSA and heart rate variability (HRV), regardless of emotional valence of the task. Third, associations between physiological responding and observed behavioral regulation are not consistently present in children aged 4 and younger. The review also provides a summary of the various methodology used to measure physiological reactions to emotional-evoking tasks, including number of sensors used and placement, various baseline and emotional-evoking tasks used, methods for extracting RSA, as well as percentage of loss and reasons for loss for each study.

CONCLUSION

Characterizing the physiological reactivity of typically developing children is important to understanding the role emotional regulation plays in typical and atypical development.

Externalizing and Internalizing Problems: Associations with Family Adversity and Young Children's Adrenocortical and Autonomic Functioning

The development of child mental health problems has been associated with experiences of adversity and dysregulation of stress response systems; however, past research has largely focused on externalizing or internalizing problems (rather than their co-occurrence) and single physiological systems in high-risk adolescent samples. The present study examined whether cumulative family adversity, functioning in the hypothalamic-pituitary-adrenal axis (i.e., cortisol) and the parasympathetic nervous system (i.e., respiratory sinus arrhythmia [RSA]), and their interactions, predicted trajectories of co-occurring externalizing and internalizing problems among young children. Participants included 338 socioeconomically and racially diverse children (M age = 5.32 years, SD = .32; male = 51.8%) from a community sample. Family adversity (assessed with six measures) and child daily cortisol output and resting RSA were assessed in kindergarten. Parents, teachers, and children reported on children's externalizing and internalizing psychopathology up to three times from kindergarten to grade 1. Latent class growth analyses identified stable trajectories of externalizing and internalizing psychopathology. Trajectories were combined to create groups: co-occurring externalizing and internalizing (13.1%), externalizing-only (14.0%), internalizing-only (11.3%), and low problems (61.3%). Family adversity and resting RSA significantly positively predicted co-occurring group membership. Tests for interactions showed adversity did not significantly interact with physiological indicators to predict group membership. However, the two physiological systems interacted, such that higher and lower daily cortisol predicted internalizing group membership for children with lower and higher resting RSA, respectively. Findings support the importance of considering family context and multiple physiological systems to inform understanding of the development of mental health problems, and their co-occurrence, in early childhood.

Associations between multisystem stress reactivity and peer nominated aggression in early childhood vary by sex

There is emerging evidence that the development of problematic aggression in childhood may be associated with specific physiological stress response patterns, with both biological overactivation and underactivation implicated. This study tested associations between sex-specific patterns of stress responses across the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis and peer nominations of aggression among 271 kindergarten children (Mean age = 5.32 years; 52% Female; 44% White). Upon entry to kindergarten, children participated in a multidomain standardized stress paradigm. Changes in pre-ejection period (PEP) and salivary cortisol were assessed. On a separate day, children provided peer ratings of physical and relational aggression in a standardized interview. As expected, there was a significant three-way interaction between PEP, cortisol reactivity, and sex, but only for physical aggression. Among boys, cortisol reactivity was positively associated with physical aggression only for those with higher SNS reactivity. Findings suggest that for boys, asymmetrical and symmetrical HPA/SNS reactivity may be associated with lower and higher risk for peer-directed physical aggression, respectively. Understanding the complex associations between multisystem physiology, child sex and peer-directed aggression in early childhood may offer insight into individual differences underlying the emergence of behavioral dysregulation in early peer contexts.

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.

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.

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.

Diverse Autonomic Nervous System Stress Response Patterns in Childhood Sensory Modulation

The specific role of the autonomic nervous system (ANS) in emotional and behavioral regulation—particularly in relation to automatic processes—has gained increased attention in the sensory modulation literature. This mini-review article summarizes current knowledge about the role of the ANS in sensory modulation, with a focus on the integrated functions of the ANS and the hypothalamic-pituitary-adrenal (HPA) axis and their measurement. Research from the past decade illustrates that sympathetic and parasympathetic interactions are more complex than previously assumed. Patterns of ANS activation vary across individuals, with distinct physiological response profiles influencing the reactivity underlying automatic behavioral responses. This review article advances a deeper understanding of stress and the complex stress patterns within the ANS and HPA axis that contribute to allostatic load (AL). We argue that using multiple physiological measurements to capture individual ANS response variation is critical for effectively treating children with sensory modulation disorder (SMD) and sensory differences. We consider the relative contributions of automatic vs. deliberately controlled processes across large-scale neural networks in the development of sensorimotor function and their associated links with arousal patterns and sensory over- and under-responsivity.

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.

Elevated physiological arousal is associated with larger but more variable neural responses to small acoustic change in children during a passive auditory attention task

Little is known of how autonomic arousal relates to neural responsiveness during auditory attention. We presented N = 21 5-7-year-old children with an oddball auditory mismatch paradigm, whilst concurrently measuring heart rate fluctuations. Children with higher mean autonomic arousal, as indexed by higher heart rate (HR) and decreased high-frequency (0.15-0.8 Hz) variability in HR, showed smaller amplitude N250 responses to frequently presented (70%), 500 Hz standard tones. Follow-up analyses showed that the modal evoked response was in fact similar, but accompanied by more large and small amplitude responses and greater variability in peak latency in the high HR group, causing lower averaged responses. Similar patterns were also observed when examining heart rate fluctuations within a testing session, in an analysis that controlled for between-participant differences in mean HR. In addition, we observed larger P150/P3a amplitudes in response to small acoustic contrasts (750 Hz tones) in the high HR group. Responses to large acoustic contrasts (bursts of white noise), however, evoked strong early P3a phase in all children and did not differ by high/low HR. Our findings suggest that elevated physiological arousal may be associated with high variability in auditory ERP responses in young children, along with increased responsiveness to small acoustic changes.

Emotion dysregulation, temperamental vulnerability, and parental depression in adolescents: Correspondence between physiological and informant-report measures

Although numerous studies reveal altered respiratory sinus arrhythmia (RSA) among children, adolescents, and adults who exhibit emotion dysregulation, effects of temperamental vulnerability and parental mental health on RSA remain unclear. We evaluated the relationship among emotion regulation, RSA, and RSA reactivity in a pooled sample of 24 vulnerable and 31 resilient adolescents (mean age = 13.69 years; 60% girls), including associations with temperamental vulnerability and parental depressive symptoms. Participants watched a neutral film clip while their resting RSA was recorded, and then completed a reward and frustration task, using an affective Posner paradigm. Temperament and emotion regulation were assessed via self-report and parent report, and parents reported on their own depressive symptoms. Low resting RSA was associated with temperamental negative emotionality, whereas greater RSA reactivity to frustration was associated with maladaptive emotion regulation strategies. No significant relations were found between RSA and parental depressive symptoms. This study elucidates the role of RSA as a biomarker of individual differences in emotion dysregulation and temperamental vulnerability and stresses the importance of considering multiple units of analyses, as well as functional domains, when studying emotional responding and regulation in adolescents.

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.

Parasympathetic and sympathetic activity are associated with individual differences in neural indices of selective attention in adults

Multiple theoretical frameworks posit that interactions between the autonomic nervous system and higher-order neural networks are crucial for cognitive and emotion regulation. However, few studies have directly examined the relationship between measures of autonomic physiology and brain activity during cognitive tasks, and fewer studies have examined both the parasympathetic and sympathetic autonomic branches when doing so. Here, 93 adults completed an ERP auditory selective attention task concurrently with measures of parasympathetic activity (high-frequency heart rate variability; HF-HRV) and sympathetic activity (preejection period; PEP). We focus on the well-studied N1 ERP component to test for associations with baseline values of HF-HRV and PEP. Individuals with higher resting HF-HRV and shorter resting PEP showed larger effects of selective attention on their ERPs. Follow-up regression models demonstrated that HF-HRV and PEP accounted for unique variance in selective attention effects on N1 mean amplitude. These results are consistent with the neurovisceral integration model, such that greater parasympathetic activity is a marker of increased selective attention, as well as other theoretical models that emphasize the role of heightened sympathetic activity in more efficient attention-related processing. The present findings highlight the importance of autonomic physiology in the study of individual differences in neurocognitive function and, given the foundational role of selective attention across cognitive domains, suggest that both parasympathetic and sympathetic activity may be key to understanding variability in brain function across a variety of cognitive tasks.

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.

Parasympathetic reactivity and disruptive behavior problems in young children during interactions with their mothers and other adults: A preliminary investigation

Parasympathetic nervous system influences on cardiac functions-commonly indexed via respiratory sinus arrhythmia (RSA)-are central to self-regulation. RSA suppression during challenging emotional and cognitive tasks is often associated with better emotional and behavioral functioning in preschoolers. However, the links between RSA suppression and child behavior across various challenging interpersonal contexts remains unclear. The present study experimentally evaluated the relationship between child RSA reactivity to adult (mother vs. study staff) direction and disruptive behavior problems in children ages 3-8 with varying levels of disruptive behavior problems (N = 43). Reduced RSA suppression in the context of mothers' play-based direction was associated with more severe child behavior problems. In contrast, RSA suppression in the context of staff play-based direction was not associated with behavior problems. Findings suggest that the association between RSA suppression and child behavior problems may vary by social context (i.e., mother vs. other adult direction-givers). Findings are discussed in regard to RSA as an indicator of autonomic self-regulation that has relevance to child disruptive behavior problems.

Early caregiving stress exposure moderates the relation between respiratory sinus arrhythmia reactivity at 1 month and biobehavioral outcomes at age 3

There is a growing scientific interest in the psychophysiological functioning of children living in low-socioeconomic status (SES) contexts, though this research is complicated by knowledge that physiology-behavior relations often operate differently in these environments among adults. Importantly, such research is made more difficult because SES may be a proxy for a wide range of risk factors including poor caregiving and exposure to parental substance use. We used factor analysis to organize risk-exposure data collected from 827 children-many of whom were raised in low-SES contexts and exposed to substances prenatally-into dissociable components including economic stress, caregiving stress (e.g., stress the caregiver may experience, including parental psychopathology), and postnatal substance exposure. These factors, along with respiratory sinus arrhythmia (RSA) reactivity at age 1 month, were used to predict behavior dysregulation and resting RSA at age 3 years. A significant RSA Reactivity × Caregiving Stress interaction indicated that infants who exhibited high RSA reactivity at 1 month experienced the greatest behavior dysregulation at 3 years, but only when they were exposed to high levels of caregiving stress. Among African Americans, the highest resting RSA at 3 years was found in infants with less RSA reactivity, but only if they also experienced less caregiving stress. Our work is consistent with biological sensitivity to context, adaptive calibration, and allostatic load models, and highlights the importance of studying Physiology × Environment interactions in low-SES contexts for predicting behavior and resting RSA.

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

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

Differences in autonomic functions as related to induced stress between children with and without cerebral palsy while performing a virtual meal-making task

BACKGROUND

Efforts to improve the participation and performance of children with cerebral palsy (CP) are often related to the adaptation of environmental conditions to meet their cognitive and motor abilities. However, the influence of affective stimuli within the environment on emotion and performance, and their ability to improve or impede the children's participation has not been investigated in any systematic way although the emerging evidence suggests that it affects the individuals in many levels.

OBJECTIVES

(1) To measure autonomic responses to affective stimuli during a simulated Meal-Maker task in children with CP in comparison to children who are typically developing, and (2) to examine the interactions between autonomic functions, subjective reports of stress, and task performance among children with and without CP.

METHODS

Fifteen children with CP and 19 typically developing peers (6 to 12 years) participated. After completing behavioral questionnaires (e.g., State and Trait Anxiety Inventories), children prepared meals within a camera tracking virtual Meal-Maker environment. Either a negative, positive, or neutral visual stimulus was displayed, selected from the International Affective Picture System. Children also passively viewed the same pictures while rating their valence and arousal levels. Heart rate (HR) and skin conductance were recorded synchronously with stimulus onset.

RESULTS

Significant differences in autonomic functions were found between groups, i.e., a higher "low frequency" to "high frequency" (LF:HF) ratio in the children with CP during the meals associated with a negative stimulus (p=0.011). Only children with CP had significant positive correlations between trait anxiety and LF:HF ratio during virtual meal-making associated with positive (p=0.049) and negative stimuli (p=0.003) but not during neutral stimuli. For children with CP the amplitude of skin conductance response during passive picture viewing was significantly higher for negative than for positive stimuli (p=0.017) but there were no significant changes in autonomic responses during virtual Meal-Maker task. Significant correlations between trait anxiety, autonomic activity during the calm state and Meal-Maker performance outcomes were found only for children with CP.

CONCLUSIONS

In general, the Meal-Maker virtual environment was shown to be a feasible platform for the investigation of the effect of emotionally loaded stimuli on the balance of autonomic functions in children with and without CP. Anxiety level appears to play a significant role in children with CP and should be considered as a potentially important factor during clinical evaluation and intervention. Further studies are needed to develop additional measurements of emotional responses and to refine the types of affective interference.

Socioeconomic Adversity, Negativity in the Parent Child-Relationship, and Physiological Reactivity: An Examination of Pathways and Interactive Processes Affecting Young Children's Physical Health

OBJECTIVE

We tested the hypothesis that socioeconomic status (SES) would predict children's physical health problems at the end of kindergarten among children whose parent reported greater parent-child relationship (PCR) negativity and/or who exhibited greater parasympathetic (RSA) reactivity. We also tested whether RSA and PCR negativity mediated the SES-health association.

METHODS

Data were collected from 338 children (mean [SD] age, 5.32 [.32] years) and their primary caregivers (87% biological mothers) during the fall and subsequent spring of kindergarten. In the fall, parents reported income and education level (SES) and PCR negativity, and RSA reactivity was assessed via a standardized challenge protocol for young children. In the fall and then spring, parents reported children's chronic medical conditions and physical health impairments. Multivariate regression was conducted within a structural equation-modeling framework to test hypotheses.

RESULTS

Significant interactions were found between SES and PCR negativity (b = -0.074, p = .035) and between SES and RSA reactivity (b = 0.169, p = .019) as predicts children's spring health impairment, adjusting for health in the preceding fall. Lower SES was associated with greater health impairment among children whose parents reported more PCR negativity (b = -0.110, p = .024) and children who showed greater RSA reactivity (b = -0.106, p = .011). Socioeconomic status was unrelated to physical health at low PCR negativity or RSA reactivity. Mediation models were not supported.

CONCLUSION

Parent-child relationship quality and individual differences in stress reactivity may modulate the influence of SES on physical health in childhood.

Heart rate variability and cognitive processing: The autonomic response to task demands

This study investigated variations in heart rate variability (HRV) as a function of cognitive demands. Participants completed an execution condition including the psychomotor vigilance task, a working memory task and a duration discrimination task. The control condition consisted of oddball versions (participants had to detect the rare event) of the tasks from the execution condition, designed to control for the effect of the task parameters (stimulus duration and stimulus rate) on HRV. The NASA-TLX questionnaire was used as a subjective measure of cognitive workload across tasks and conditions. Three major findings emerged from this study. First, HRV varied as a function of task demands (with the lowest values in the working memory task). Second, and crucially, we found similar HRV values when comparing each of the tasks with its oddball control equivalent, and a significant decrement in HRV as a function of time-on-task. Finally, the NASA-TLX results showed larger cognitive workload in the execution condition than in the oddball control condition, and scores variations as a function of task. Taken together, our results suggest that HRV is highly sensitive to overall demands of sustained attention over and above the influence of other cognitive processes suggested by previous literature. In addition, our study highlights a potential dissociation between objective and subjective measures of mental workload, with important implications in applied settings.

Experimental manipulation of the Trier Social Stress Test-Modified (TSST-M) to vary arousal across development

Reliable laboratory protocols manipulating the intensity of biobehavioral arousal for children are uncommon, and those available have minimal converging evidence of their efficacy in manipulating arousal across multiple biological systems. This report presents two studies of the efficacy of the modified Trier Social Stress Test (TSST-M). In Study 1, sixty-three 7-15-year olds, and 19 young adults (18-25 yrs) completed the TSST-M. Comparable reactivity across age groups was observed for salivary cortisol, salivary alpha-amylase (sAA), pre-ejection period (PEP) and respiratory sinus arrhythmia (RSA), whereas self-reported stress was higher in adults compared to children. In Study 2, eighty-four 7-8-year olds and eighty-six 12-15-year olds were randomly assigned to a standard or low-stress TSST-M condition. Cortisol and self-reported stress responses were higher in the standard compared to the low-stress condition. In contrast, sAA and PEP were higher in the low-stress condition and RSA responses were comparable between the two TSST-M conditions. In addition, age group differences emerged in Study 2, though never in conjunction with the TSST-M manipulation. To test, refine, and advance theory about the implications of stress for child development, laboratory tasks that manipulate and enable assessment of biobehavioral arousal in children are needed.

Growth models of dyadic synchrony and mother-child vagal tone in the context of parenting at-risk

We used multilevel modeling to examine dynamic changes in respiratory sinus arrhythmia (RSA) and observer-coded interactive synchrony for mother-child dyads engaged in a laboratory interaction, to characterize parenting-at-risk. Seventy-nine preschooler-mother dyads including a subset with documented child maltreatment (CM; n=43) were observed completing a joint puzzle task while physiological measures were recorded. Dyads led by CM mothers showed decreases in positive synchrony over time, whereas no variation was observed in non-CM dyads. Growth models of maternal RSA indicated that mothers who maintained high levels of positive interactive synchrony with their child evidenced greater RSA reactivity, characterized by an initial withdrawal followed by augmentation as the task progressed, after accounting for CM group status. These results help to clarify patterns of RSA responding in the context of caregiver-child interactions, and demonstrate the importance of modeling dynamic changes in physiology over time in order to better understanding biological correlates of parenting-at-risk.

Racial identity and autonomic responses to racial discrimination

Several studies identify racial identity-the significance and meaning that individuals attribute to race-as a mitigating factor in the association between racial discrimination and adjustment. In this study, we employed a visual imagery paradigm to examine whether racial identity would moderate autonomic responses to blatant and subtle racial discrimination analogues with Black and White perpetrators. We recruited 105 African American young adults from a public, southeastern university in the United States. The personal significance of race as well as personal feelings about African Americans and feelings about how others view African Americans moderated autonomic responses to the vignettes. We use polyvagal theory and a stress, appraisal, and coping framework to interpret our results with an eye toward elucidating the ways in which racial identity may inform individual differences in physiological responses to racial discrimination.

Kindergarten stressors and cumulative adrenocortical activation: the "first straws" of allostatic load?

Using an ethnically diverse longitudinal sample of 338 kindergarten children, this study examined the effects of cumulative contextual stressors on children's developing hypothalamic-pituitary-adrenocortical (HPA) axis regulation as an early life indicator of allostatic load. Chronic HPA axis regulation was assessed using cumulative, multiday measures of cortisol in both the fall and spring seasons of the kindergarten year. Hierarchical linear regression analyses revealed that contextual stressors related to ethnic minority status, socioeconomic status, and family adversity each uniquely predicted children's daily HPA activity and that some of those associations were curvilinear in conformation. Results showed that the quadratic, U-shaped influences of family socioeconomic status and family adversity operate in different directions to predict children's HPA axis regulation. Results further suggested that these associations differ for White and ethnic minority children. In total, this study revealed that early childhood experiences contribute to shifts in one of the principal neurobiological systems thought to generate allostatic load, confirming the importance of early prevention and intervention efforts. Moreover, findings suggested that analyses of allostatic load and developmental theories accounting for its accrual would benefit from an inclusion of curvilinear associations in tested predictive models.