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

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.

Vagal flexibility to negative emotions moderates the relations between environmental risk and adjustment problems in childhood

Neurobiological and social-contextual influences shape children's adjustment, yet limited biopsychosocial studies have integrated temporal features when modeling physiological regulation of emotion. This study explored whether a common underlying pattern of non-linear change in respiratory sinus arrhythmia (RSA) across emotional scenarios characterized 4-6 year-old children's parasympathetic reactivity (N = 180). Additionally, we tested whether dynamic RSA reactivity was an index of neurobiological susceptibility or a diathesis in the association between socioeconomic status, authoritarian parenting, and the development of externalizing problems (EP) and internalizing problems over two years. There was a shared RSA pattern across all emotions, characterized by more initial RSA suppression and a subsequent return toward baseline, which we call vagal flexibility (VF). VF interacted with parenting to predict EP. More authoritarian parenting predicted increased EP two years later only when VF was low; conversely, when VF was very high, authoritarian mothers reported that their children had fewer EP. Altogether, children's patterns of dynamic RSA change to negative emotions can be characterized by a higher order factor, and the nature by which VF contributes to EP depends on maternal socialization practices, with low VF augmenting and high VF buffering children against the effects of authoritarian parenting.

Parental drug use disorders and youth psychopathology: Meta-analytic review

Parental drug use disorders (PDUDs) represent a highly prevalent risk factor for youth's development of psychological and substance misuse. However, most research on associations between parental substance use and child mental health focuses on composites of parental drug, alcohol, and tobacco use. PDUDs are associated with a range of legal, health, and environmental risks that make them substantially distinct from tobacco and alcohol misuse, yet associations between PDUDs and youth psychopathology symptoms have yet to be assessed quantitatively using meta-analytic techniques. Accordingly, the present meta-analysis assessed the association between PDUDs and youth's internalizing, externalizing, substance use, and total psychological problems across 30 studies (N = 8433). Meta-analytic findings showed that PDUDs were associated with greater substance use and total psychological problems in youth. Across studies, PDUDs were not associated with broad dimensions of youth internalizing and externalizing symptoms but demonstrated a positive relation with youth ADHD and conduct disorder symptoms. There were significant moderation effects for study quality, symptom informant, and child age, where the association between PDUDs and child symptoms of psychopathology was stronger for older youth, in higher quality studies, and studies using joint parent-child symptom informants. Taken together, the meta-analytic findings suggest that PDUDs present a significant risk factor for youth. Future research targeting the relation between parental drug use and youth psychopathology is warranted for prevention and intervention efforts. Implication of findings, mechanisms of interest, and an agenda for future research are discussed.

Early exposure to parent-perpetrated intimate partner violence predicts hypervigilant error monitoring

Early exposure to intimate partner violence (IPV) places children at risk for ongoing emotional difficulties, including problems with self-regulation and high levels of internalizing symptoms. However, the impact of IPV exposure on children's error monitoring remains unknown. The present study utilized electroencephalography (EEG) to examine the impact of exposure to IPV in infancy on error monitoring in middle childhood. Results indicated that parents' perpetration of IPV against their romantic partners when children were under 24 months of age predicted hypervigilant error monitoring in children at age 8 (N = 30, 16 female), as indexed by error-related neural activity (ERN and Pe difference amplitudes), above and beyond the effects of general adversity exposure and parental responsiveness. There was no association between partner perpetration of IPV and children's error monitoring. Results illustrate the harmful effects of early exposure to parent-perpetrated IPV on error monitoring and highlight the importance of targeting children's and parents' cognitive and emotional responses to error commission in psychotherapy.

Paternal biopsychosocial resilience in triadic interactions among African American/Black families exposed to trauma and socioeconomic adversity

Fathers have a distinct and unique effect on child development, but little is known about fathering beyond White or majority White families. The current study includes African American/Black biological fathers (N = 88) and their two-year-old children. Fathers reported low incomes and high rates of depression and posttraumatic stress disorder (PTSD). Parenting behaviors were observed in high-stress and low-stress triadic contexts. In the high-stress condition, we assessed paternal responses to children's bids after the family was reunited following a separation paradigm. In the low-stress condition, we assessed parenting behaviors during a teaching task. Fathers' social baseline respiratory sinus arrhythmia (RSA) was obtained as an index of parasympathetic arousal. RSA moderated the association between PTSD and fathers' responsiveness (F = 6.90, p = .00, R²  = .30), with no association between PTSD and responsiveness demonstrated among fathers with the highest levels of RSA relative to the sample (effect = .04, p = .00; CI [0.02, 0.06]). RSA did not moderate the association between paternal depression and parenting behaviors (p > .05). Furthermore, responsiveness was only significantly associated with low-stress paternal teaching behaviors for fathers with lower RSA (F = 4.34, p = .01, R²  = .21; effect = -.19, p = .00; CI [0.06, 0.32]). Findings demonstrate significant relationships among RSA, PTSD, and parenting for African American/Black men in contexts of economic adversity.

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.

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.

Social Stress-Related Epigenetic Changes Associated With Increased Heart Rate Variability in Infants

Early life stress can result in persistent alterations of an individual’s stress regulation through epigenetic modifications. Epigenetic alteration of the NR3C1 gene is associated with changes in the stress response system during infancy as measured by cortisol reactivity. Although autonomic nervous system (ANS) reactivity is a key component of the stress response, we have a limited understanding of the effects of NR3C1 DNA methylation on ANS reactivity. To examine this relation, ANS stress responses of term, 4–5-month-old healthy infants were elicited using the face-to-face still-face paradigm, which involved five, 2-min episodes. Two of these episodes were the “still-face” in which the mother was non-responsive to her infant. EKG was acquired continuously and analyzed in 30 s-intervals. Cheek swabs were collected, and DNA was extracted from buccal cells. Respiratory sinus arrhythmia (RSA) was measured as heart rate variability (HRV). Mean HRV was calculated for each 30-s “face to face” episode. DNA methylation of NR3C1 was calculated using bisulfite pyrosequencing. Percent DNA methylation was computed for each of the 13 NR3C1 CpG sites. The relations between mean HRV for each “face to face” episode and percent DNA methylation was examined averaged over CpG sites 1–6 and 7–13 and at each individual CpG site. Higher HRV at baseline, first reunion, and second still-face was related to greater methylation of NR3C1 CpG sites 1–6. Higher HRV at the second reunion was related to greater methylation of NR3C1 CpG sites 12 and 13. These data provide evidence that increased methylation of NR3C1 at CpG sites 12 and 13 are associated with increased activation of parasympathetic pathways as represented by increased HRV.

Infant Parasympathetic and Sympathetic Activity during Baseline, Stress and Recovery: Interactions with Prenatal Adversity Predict Physical Aggression in Toddlerhood

Exposure to prenatal adversity is associated with aggression later in life. Individual differences in autonomic nervous system (ANS) functioning, specifically nonreciprocal activation of the parasympathetic (PNS) and sympathetic (SNS) nervous systems, increase susceptibility to aggression, especially in the context of adversity. Previous work examining interactions between early adversity and ANS functioning in infancy is scarce and has not examined interaction between PNS and SNS. This study examined whether the PNS and SNS moderate the relation between cumulative prenatal risk and early physical aggression in 124 children (57% male). Cumulative risk (e.g., maternal psychiatric disorder, substance (ab)use, and social adversity) was assessed during pregnancy. Parasympathetic respiratory sinus arrhythmia (RSA) and sympathetic pre-ejection period (PEP) at baseline, in response to and during recovery from emotional challenge were measured at 6 months. Physical aggression and non-physical aggression/oppositional behavior were measured at 30 months. The results showed that cumulative prenatal risk predicted elevated physical aggression and non-physical aggression/oppositional behavior in toddlerhood; however, the effects on physical aggression were moderated by PNS and SNS functioning. Specifically, the effects of cumulative risk on physical aggression were particularly evident in children characterized by low baseline PNS activity and/or by nonreciprocal activity of the PNS and SNS, characterized by decreased activity (i.e., coinhibition) or increased activity (i.e., coactivation) of both systems at baseline and/or in response to emotional challenge. These findings extend our understanding of the interaction between perinatal risk and infant ANS functioning on developmental outcome.

Stress and parenting predict changes in adolescent respiratory sinus arrhythmia

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Understanding the Victimization-Aggression Link in Childhood: The Roles of Sympathy and Resting Respiratory Sinus Arrhythmia

With a sample of 4- and 8-year-olds (N = 131), we tested the extent to which more frequent experiences of victimization were associated with heightened aggression towards others, and how sympathetic concern and resting respiratory sinus arrhythmia (RSA) factored into this relationship. Caregivers reported their children's aggression and sympathy. Children reported their victimization and their resting RSA was calculated from electrocardiogram data in response to a nondescript video. Findings revealed that children who reported more frequent victimization were rated as less sympathetic and, in turn, more aggressive. However, resting RSA moderated this path, such that children with high levels were rated as more versus less sympathetic when they reported less versus more victimization, respectively. Results suggest that considering children's sympathetic tendencies and physiology is important to gain a nuanced understanding of their victimization-related aggression.

A developmental origins perspective on the emergence of violent behavior in males with prenatal substance exposure

Children with prenatal substance exposure are at increased risk for externalizing behavior problems and violence. However, the contribution of early life experiences for placing these individuals at risk is not well understood. Utilizing a sample of 1,388 children with prenatal substance exposure from the Maternal Lifestyle Study, we attempt to shed light on these contributing factors by examining the impact of infant temperament, maternal sensitivity, and early life stress on the expression of violent behavior at ages 12 through 14 years. Males may be more at risk for increases in violent behavior in early adolescence through a number of early life experiences, such as variability in responses to maternal flexibility and engagement related to individual differences in temperament, as well as exposure to early adversity. Comparing two prevailing developmental theoretical frameworks, deficit models and differential susceptibility, we aim to understand the developmental origins of violent behavior in males by identifying children who may be most susceptible to early caregiving experiences.

Testing the programming of temperament and psychopathology in two independent samples of children with prenatal substance exposure

Prenatal programming models have rarely been applied to research on children with prenatal substance exposure, despite evidence suggesting that prenatal drug exposure is a form of stress that impacts neurodevelopmental outcomes and risk for psychopathology. Utilizing data from two longitudinal multisite studies comprising children prenatally exposed to substances as well as a nonexposed comparison group (Maternal Lifestyle Study, n = 1,388; Infant Development, Environment, and Lifestyle study, n = 412), we tested whether early phenotypic indicators of hypothesized programming effects, indexed by growth parameters at birth and infant temperament, served as a link between prenatal substance exposure and internalizing and externalizing behavior at age 5. Latent profile analysis indicated that individual differences in reactivity and regulation for infants prenatally exposed to substances was best characterized by four temperament profiles. These profiles were virtually identical across two independent samples, and demonstrated unique associations with adjustment difficulties nearly 5 years later. Results of path analysis using structural equation modeling also showed that increased prenatal substance exposure was linked to poorer growth parameters at birth, profiles of temperamental reactivity in infancy, and internalizing and externalizing behavior at age 5. This pathway was partially replicated across samples. This study was among the first to link known individual-level correlates of prenatal substance exposure into a specific pathway to childhood problem behavior. Implications for the developmental origins of a child's susceptibility to psychopathology as a result of intrauterine substance exposure are discussed.

Cumulative risk exposure moderates the association between parasympathetic reactivity and inhibitory control in preschool-age children

A child's cumulative risk for early exposure to stress has been linked to alterations of self-regulation outcomes, including neurobiological correlates of inhibitory control (IC). We examined whether children's ability to engage the parasympathetic nervous system impacts how risk affects IC. Children ages 3-5 years completed two laboratory measures of IC while respiratory sinus arrhythmia (RSA) was measured, indexing parasympathetic activity. Children with greater risk demonstrated lower IC; risk also moderated associations between RSA reactivity and IC. For children with less risk, greater RSA withdrawal during IC tasks was associated with better IC. In contrast, greater risk was associated with poor IC, regardless of RSA withdrawal. Effects of risk were more pronounced for cumulative than individual measures. Results suggest that cumulative risk exposure disrupts connectivity between physiological and behavioral components of self-regulation in early childhood. Parasympathetic withdrawal to cognitive tasks may be less relevant for performance in developmental samples experiencing greater life stress.

Parent-child coregulation of parasympathetic processes varies by social context and risk for psychopathology

The parasympathetic nervous system supports social interaction and varies in relation to psychopathology. However, we know little about parasympathetic processes from a dyadic framework, nor in early childhood when parent-child social interactions become more complex and child psychopathology first emerges. We hypothesized that higher risk for psychopathology (maternal psychopathology symptoms and child problem behavior) would be related to weaker concordance of respiratory sinus arrhythmia (RSA) between mothers and children (M = 3½ years old; N = 47) and that these relations could vary by social contextual demands, comparing unstructured free play, semistructured cleanup, and structured teaching tasks. Multilevel coupled autoregressive models of RSA during parent-child interactions showed overall dynamic, positive concordance in mother-child RSA over time, but this concordance was weaker during the more structured teaching task. In contrast, higher maternal psychological aggression and child externalizing and internalizing problems were associated with weaker dyadic RSA concordance, which was weakest during unstructured free play. Higher maternal depressive symptoms were related to disrupted individual mother and child RSA but not to RSA concordance. Thus, risk for psychopathology was generally related to weaker dyadic mother-child RSA concordance in contexts with less complex structure or demands (free play, cleanup), as compared to the structured teaching task that showed weaker RSA concordance for all dyads. Implications for the meaning and utility of the construct of parent-child physiological coregulation are discussed.

Quantifying respiratory sinus arrhythmia: Effects of misspecifying breathing frequencies across development

Low resting respiratory sinus arrhythmia (RSA), and to a lesser extent excessive RSA reactivity to emotion evocation, are observed in many psychiatric disorders characterized by emotion dysregulation, including syndromes spanning the internalizing and externalizing spectra, and other conditions such as nonsuicidal self-injury. Nevertheless, some inconsistencies exist. For example, null outcomes in studies of RSA–emotion dysregulation relations are sometimes observed among younger participants. Such findings may derive from use of age inappropriate frequency bands in calculating RSA. We combine data from five published samples (N = 559) spanning ages 4 to 17 years, and reanalyze RSA data using age-appropriate respiratory frequencies. Misspecifying respiratory frequencies results in overestimates of resting RSA and underestimates of RSA reactivity, particularly among young children. Underestimates of developmental shifts in RSA and RSA reactivity from preschool to adolescence were also observed. Although correlational analyses revealed weak negative associations between resting RSA and aggression, those with clinical levels of externalizing exhibited lower resting RSA than their peers. No associations between RSA reactivity and externalizing were observed. Results confirm that age-corrected frequency bands should be used when estimating RSA, and that literature-wide overestimates of resting RSA, underestimates of RSA reactivity, and underestimates of developmental shifts in RSA and RSA reactivity may exist.

Diversity and representation: Key issues for psychophysiological science

This Special Issue is devoted to the illustration and discussion of three key demographic variables (sex/gender, race/ethnicity, and socioeconomic status) that have been shown to moderate associations between psychophysiological processes and behavior. The introduction to the issue discusses the role of phenotypic plasticity in the emergence of different neural processes that achieve the same behavioral outcome, with emphasis on how these relatively stable developmental contexts affect brain/behavior associations without necessarily resulting in difference in behavior. These findings have profound significance for the implications of generalization and call into question the presumption that diverse samples produce an average result that is appropriately reflective of the individuals themselves. Increasing diversity within psychophysiological research is critical in elucidating mechanisms by which the human brain can accomplish cognitive and affective behaviors. This article further examines the logistical and ethical challenges faced in achieving this goal.