The implications of sympathetic and parasympathetic regulatory coordination for understanding child adjustment

A longitudinal investigation of caregiving and adolescent post-traumatic stress symptoms during COVID-19: evidence for high resting RSA as a susceptibility factor

BACKGROUND

Post-traumatic stress symptoms (PTSS) were the most frequently reported mental health concern for youth during COVID-19, yet variations in youth's PTSS responses warrant empirical consideration. Features of the caregiving environment influence youth's responses to environmental stressors, and youth's parasympathetic nervous system regulation may qualify the magnitude and/or direction of these effects. This prospective investigation evaluated diathesis stress and differential susceptibility models of caregiving and parasympathetic influences on youth's PTSS responses to COVID-19.

METHOD

Participants were 225 caregiver-youth dyads (youth 49.8% female at birth; 88.4% non-white) followed from childhood through adolescence and COVID-19. Youth's resting respiratory sinus arrhythmia (RSA; Mage = 6.11, s.d. = 0.21), caregiving features (i.e. attachment security [youth Mage = 12.24, s.d. = 0.35] and caregiver internalizing psychopathology [caregiver Mage = 39.29, s.d. = 6.78]) were assessed pre-pandemic. Youth's PTSS was assessed one year prior to the US COVID-19 pandemic (Mage = 14.24, s.d. = 0.50) and during the spring of 2020 at the height of the pandemic (Mage = 15.23, s.d. = 0.57).

RESULTS

Youth's PTSS increased during COVID-19. Youth with relatively high resting RSA evidenced the lowest PTSS when their caregiving environment featured high attachment security or low caregiver internalizing problems, but the highest PTSS when their caregiving environment featured low attachment security or high caregiver internalizing problems. In contrast, PTSS levels of youth with relatively low or average resting RSA did not differ significantly depending on attachment security or caregiver internalizing.

CONCLUSIONS

Results are consistent with a differential susceptibility hypothesis, wherein relatively high resting RSA conferred heightened sensitivity to caregiving environments in a for-better-and-for-worse manner during COVID-19.

The interactive roles of narrative processing and emotion negativity/lability in relation to autonomic coordination

Emotion regulation (ER) is a multifaceted construct, involving behavioral, cognitive, and physiological processes. Although autonomic coordination is theorized to play a crucial role in adaptive functioning, few studies have examined how different individual and contextual factors together may contribute to such coordination. This study examined the joint influences of narrative processing and emotional negativity/lability (N/L) traits on the coordination of the sympathetic and parasympathetic nervous systems in a sample of 112 children, ages 8-12 years (Mage = 10.15 years, SD = 1.33). Children completed a stress-induction task followed by an interview about the task. Children's trait-level N/L was assessed via parent-report on the Emotion Regulation Checklist. Narrative processing was assessed and coded based on children's narrative accounts of the event (i.e., causal coherence, overall emotional tone). Indexes of sympathetic (skin conductance response, SCR) and parasympathetic (respiratory sinus arrhythmia, RSA) functioning were derived from physiological data obtained during the interview. Results revealed that children's trait-level N/L and narrative processing of the stressful event interacted to predict the RSA-SCR correlation. Specifically, children who were high on either N/L or narrative causal coherence, but not both, demonstrated significant RSA-SCR correlation. Similarly, children with high N/L and negative-to-neutral narratives, as well as those with low N/L and neutral-to-positive narratives, exhibited significant RSA-SCR correlation. This work provides empirical evidence that narrative processing and trait N/L, together with RSA-SCR correlation, work in tandem to regulate emotional arousal.

Autonomic nervous system reactivity to emotion and childhood trajectories of relational and physical aggression

This study investigated the role of autonomic nervous system (ANS) coordination in response to emotion in girls' and boys' development of relational (e.g., ignoring, excluding) and physical (e.g., hitting, kicking) aggression. Caregivers reported on children's relational and physical aggression at ages 6, 7, 8, and 10 years (N = 232, 50.4% girls, 46.6% Latinx). Sympathetic nervous system (assessed via pre-ejection period) and parasympathetic nervous system (assessed via respiratory sinus arrhythmia) reactivity were measured in response to video clips depicting fear, happiness, and sadness at age 7. Growth curve models indicated that ANS reactivity to sadness, but not to fear or happiness, was related to trajectories of relational aggression. In contrast, ANS reactivity to all three emotions was associated with trajectories of physical aggression. Effects differed across genders, indicating that distinct patterns of ANS reactivity to emotion may be involved in girls' and boys' development of aggression. Overall, these findings contribute to a growing literature documenting the role of ANS reactivity to emotion in aggressive behavior. Moreover, this study considers ANS reactivity to specific emotions, as related to both relational and physical aggression, and as differentially expressed among girls versus boys.

A Virtual Reality Courtroom for Survivors of Sexual Violence: A Mixed-Method Pilot Study on Application Possibilities

This mixed-method pilot study examined the application possibilities of a virtual courtroom to support survivors of sexual violence who may experience courtroom-associated distress. Female sexual violence survivors (n = 13) who had testified in court following victimization entered an interactive virtual courtroom replica. Their reactions were measured quantitatively and qualitatively. The virtual courtroom evoked both subjective and physiological stress. Participants perceived the virtual reality environment as similar to the real-life courtroom. Most reported negative experiences from interacting with the criminal justice system. The virtual courtroom is a possible future strategy to support survivors when reporting violence to the justice system.

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.

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

OBJECTIVE

Maternal health and wellness during pregnancy are associated with long-term health outcomes in children. The current study examined whether infants of women who participated in a mindfulness-based intervention during pregnancy that reduced levels of stress and depression, increased physical activity, and improved glucose tolerance differed on biobehavioral markers of psychopathological and physical health risk compared with infants of women who did not.

METHODS

Participants were 135 mother-infant dyads drawn from a racially and ethnically diverse, low-income sample experiencing high stress. The women participated in an intervention trial during pregnancy that involved assignment to either mindfulness-based intervention or treatment-as-usual (TAU). Infants of women from both groups were assessed at 6 months of age on sympathetic (preejection period), parasympathetic (respiratory sinus arrhythmia), and observed behavioral (negativity and object engagement) reactivity and regulation during the still face paradigm. Linear mixed-effects and generalized linear mixed-effects models were used to examine treatment group differences in infant outcomes.

RESULTS

Relative to those in the intervention group, infants in the TAU group showed a delay in sympathetic activation and subsequent recovery across the still face paradigm. In addition, infants in the intervention group engaged in higher proportions of self-regulatory behavior during the paradigm, compared with the TAU group. No significant effect of intervention was found for parasympathetic response or for behavioral negativity during the still face paradigm.

CONCLUSIONS

Findings provide evidence that maternal participation in a short-term, group mindfulness-based intervention during pregnancy is associated with the early development of salutary profiles of biobehavioral reactivity and regulation in their infants. Because these systems are relevant for psychopathology and physical health, prenatal behavioral interventions may benefit two generations.

The impact of social disadvantage on autonomic physiology of latinx adolescents: The role of environmental risks

The experience of poverty embodies complex, multidimensional stressors that may adversely affect physiological and psychological domains of functioning. Compounded by racial/ethnic discrimination, the financial aspect of family poverty typically coincides with additional social and physical environmental risks such as pollution exposure, housing burden, elevated neighborhood unemployment, and lower neighborhood education levels. In this study, we investigated the associations of multidimensional social disadvantage throughout adolescence with autonomic nervous system (ANS) functioning at 17 years. Two hundred and twenty nine low-income Mexican-American adolescents (48.6% female) and their parents were assessed annually between the ages of 10 and 16. Participants' census tracts were matched with corresponding annual administrative data of neighborhood housing burden, education, unemployment, drinking water quality, and fine particulate matter. We combined measures of adolescents' electrodermal response and respiratory sinuses arrhythmia at rest and during a social exclusion challenge (Cyberball) to use as ANS indices of sympathetic and parasympathetic activity, respectively. Controlling for family income-to-needs, youth exposed to greater cumulative water and air pollution from ages 10-16 displayed altered patterns of autonomic functioning at rest and during the social challenge. Conversely, youth living in areas with higher housing burden displayed healthy patterns of autonomic functioning. Altogether, results suggest that toxin exposure in youths' physical environments disrupts the ANS, representing a plausible mechanism by which pollutants and social disadvantage influence later physical and mental health.

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.

The role of stress reactivity and pre-injury psychosocial vulnerability to psychological and physical health immediately after traumatic injury

BACKGROUND

Traumatic injuries can have long-term negative impacts on health, especially psychological health. A biopsychosocial approach is recommended to identify those likely to experience psychosocial stress, however large individual differences exist in stress reactivity and post-injury health that remain unexplored. Therefore, we investigated autonomic nervous system (ANS) stress responses and pre-existing psychosocial vulnerability as contributors to health in individuals who sustained a traffic-related injury.

METHODS

120 adults with traffic-related injury and 112 non-injury controls underwent an integrative ANS (cardiac and skin conductance) assessment and a health-related assessment at 3-6 weeks post-injury. Propensity score matching based on six pre-injury psychosocial vulnerability factors (age, sex, education, prior mental/physical health, socioeconomic status) guided the definition of high vulnerability (HV) and low vulnerability (LV) injury subgroups, with the LV subgroup having similar propensity scores to non-injury controls. A three-group comparative analysis of ANS responsivity (baseline, reactivity, recovery/rebound) and post-injury health was performed.

RESULTS

The HV subgroup exhibited the most negative immediate post-injury mental health profile and less adaptive ANS response patterns, indicating greater stress vulnerability/reactivity. Significant differences were found for psychological health (elevated psychological distress and catastrophizing), but not physical health (injury factors, pain, fatigue, physical wellbeing). HV participants showed sympathetic predominance at resting baseline (lower parasympathetic activity and/or elevated heart rate) compared to the LV and control groups, as well as smaller parasympathetic decrease during a cognitive task compared to controls. Despite preserved capacity for restoring initial homeostasis in both injury subgroups during recovery, there was some indication of blunted post-task sympathetic deactivation (larger sympathetic decrease) and reduced overall ANS adaptability (reduction in total power of heart rate variability spectrum), suggesting relative reduced capacity to face stressors compared to controls.

CONCLUSIONS

Findings suggest that baseline resting ANS regulation, particularly parasympathetic activity, and pre-injury psychosocial factors are key contributors to individual psycho-biological responses following traumatic injury, and are therefore potential stress vulnerability markers. Post-stress recovery patterns may represent a novel physiological signature for a "biological intrinsic" vulnerability early after the injury. These findings provide direction for improved early identification and management of injured individuals, including innovative preventive interventions that target ANS regulation.

The Development of Generosity From 4 to 6 Years: Examining Stability and the Biopsychosocial Contributions of Children's Vagal Flexibility and Mothers' Compassion

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

Charting the physiological time course of help-seeking during late childhood: Patterns of individual difference

In this study, we explored whether variability in children's physiological reactivity-respiratory sinus arrhythmia and electrodermal activity-predict concurrent and subsequent levels of children's observed help-seeking (HS) from their mothers during a failure task. In addition, we tested whether children's perceptions of maternal positivity pre-task (CPMP) and children's fearful temperament moderate these effects. In a community sample of 101 mother-child dyads, children (8-12 years of age) underwent a repeated failure task while their respiratory sinus arrythmia and electrodermal activity were monitored; their HS behaviors were later coded. Multilevel path analyses indicated that high-fearful children increased their HS at the same time as and following increased physiological reactivity regardless of CPMP pre-task. Low-fearful children showed increases in HS at the same time as and following increased physiological reactivity only when they perceived their mothers' affect to be positive. This study demonstrates children's individual differences in the physiological underpinning of time-linked HS behaviors.

Getting to the heart of childhood empathy: Relations with shyness and respiratory sinus arrhythmia

Although prior studies have found that shyness and empathy are inversely related and that well-regulated children tend to express empathic behaviors more often, little work has assessed combinations of these factors in predicting affective and cognitive empathy in early childhood. The authors examined relations among shyness, resting respiratory sinus arrhythmia (RSA), and observed affective and cognitive empathy in a sample of 130 typically developing children (M_age  = 63.5 months, SD = 12.2; 62 males). Shyness was assessed by observing children's behaviors during a self-presentation task, and this observed measure was then combined with a maternal report of children's temperamental shyness. Children's shyness predicted lower levels of both affective and cognitive responses to an experimenter feigning an injury. Resting RSA moderated the relation between children's shyness and observed empathy such that relatively higher shyness combined with lower RSA levels conferred the lowest levels of cognitive empathy. Children who were relatively low in shyness exhibited similar levels of cognitive empathy across different levels of RSA. However, this moderation was not found when predicting children's affective empathy. Our results suggest that not all shy children are alike in terms of their empathic behaviors: shy children who are physiologically dysregulated appear to have difficulties exploring and/or processing others' pain.

A latent change score approach to understanding dynamic autonomic coordination

Children's self-regulation is a core adaptive system in child development. Physiological indices of regulation, particularly the autonomic nervous system (ANS), have garnered increased attention as an informative level of analysis in regulation research. Cardiography supports the simultaneous examination of both ANS branches via measures of pre-ejection period (PEP) and respiratory sinus arrhythmia (RSA) as indicators of sympathetic and parasympathetic activity, respectively. However, despite their heavily intertwined functions, research examining autonomic coordination across sympathetic and parasympathetic systems is scarce. Moreover, extant efforts have favored static, mean level reactivity analyses, despite the dynamic nature of ANS regulation and the availability of analytic tools that can model these processes across time. This study drew on a sample of 198 six-year-old children from a diverse community sample (49.5% female, 43.9% Latinx) to examine dynamic autonomic coordination using bivariate latent change score modeling to evaluate bidirectional influences of sympathetic and parasympathetic activity over the course of a challenging puzzle completion task. Results indicated that children evidenced reciprocal sympathetic activation (i.e., PEP attenuation and RSA withdrawal) across the challenge task, and these regulatory responses were characterized by a temporally leading influence of PEP on lagging changes in RSA. The current findings contribute to our understanding of children's autonomic coordination while illustrating a novel analytic technique to advance ongoing efforts to understand the etiology and developmental significance of children's physiological self-regulation.

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.

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.