Leveraging parasympathetic nervous system activity to study risk for psychopathology: The special case of callous-unemotional traits

Testosterone, cortisol, and psychopathy: Further evidence with the Levenson self-report psychopathy scale and the inventory of callous unemotional traits

The current study explored associations between testosterone, cortisol, and both the Levenson Self-Report Psychopathy Scale (LSRPS) and the Inventory of Callous Unemotional (ICU) traits. Data were gathered from a relatively large sample of university students (n = 522) and analyses considered direct and interactive associations between hormones and psychopathic traits, as well as interactions between these associations and the time of day at which samples were gathered and the sex of participants. Baseline cortisol had a negative association with LSRPS primary psychopathy scores. In addition, baseline cortisol interacted with the time of day in association with LSRPS total scores. Simple slopes analyses indicated cortisol had a negative association with LSRPS total scores in the morning but not the afternoon. Interactions among hormone measures were not statistically significant. There was also no evidence for the moderation of associations between hormones and psychopathic traits by sex.

Resting heart rate moderates the relationship between parental emotion socialization and callous-unemotional traits in children

Although empirical findings have indicated that both familial and neurobiological risk factors contribute to the development of callous-unemotional (CU) traits in children, relatively few studies have investigated how these two factors interact to influence these traits. The current study focused on the combined effects of parental emotion socialization and child's resting heart rate on CU traits. Parents of Chinese children (N = 166) completed the Coping with Children's Negative Scale when children were 9.39 years old (SD = 0.92), while children's resting heart rate data were collected when they were 10.21 years old (SD = 0.72). When they were 11.15 years old (SD = 0.67), parents completed the Inventory of Callous-Unemotional Traits Short-Form. Results showed that parental supportive emotion socialization was negatively associated with CU traits and Callous behaviors in particular. In addition, resting heart rate moderated the relationship between parental emotion socialization and child's CU traits. Findings provide further evidence that an interdisciplinary approach that combines both psychosocial and biological factors is essential to further our understanding of CU traits in youth.

Fearlessness as an Underlying Mechanism Leading to Conduct Problems: Testing the INTERFEAR Model in a Community Sample in Spain

Conduct problems (CP) in childhood and adolescence have a significant impact on the individual, family, and community. To improve treatment for CP, there is a need to improve the understanding of the developmental pathways leading to CP in boys and girls. Prior research has linked the child's fearlessness and callous-unemotional (CU) traits, as well as experiences of parental warmth and punitive parenting, to CP. However, few studies have tested the interplay of these factors in contributing to future CP development. The present study aimed to test the InterFear model, which suggests that fearlessness in early childhood leads to CP through an indirect pathway involving low positive parenting, high negative/punitive parenting, and callous-unemotional (CU) traits. The sample included 2467 Spanish children (48.1% girls; Mage = 4.25; SD = 0.91), followed up across a five-year period. Besides a direct association between fearlessness in early childhood and future CP, the results found an indirect pathway whereby fearlessness reduces positive parenting and increases punitive parenting, which contributes to the development of CU traits and sets the stage for CP in later childhood. The specific indirect effect from fearlessness to CP via CU traits accounted for most of the variance, suggesting the existence of a temperamental pathway independent of parental variables. Further, two additional indirect pathways, exclusive of fearlessness, were identified, which started with low parental warmth and positive parenting, leading to CP via CU traits. These findings support the InterFear model, demonstrating multiple pathways to CP with the involvement of fearlessness, parenting practices, and CU traits. This model might play a pivotal role in the development of targeted prevention and intervention strategies for CP.

Understanding emotion dysregulation from infancy to toddlerhood with a multilevel perspective: The buffering effect of maternal sensitivity

Challenges with childhood emotion regulation may have origins in infancy and forecast later social and cognitive developmental delays, academic difficulties, and psychopathology. This study tested whether markers of emotion dysregulation in infancy predict emotion dysregulation in toddlerhood, and whether those associations depended on maternal sensitivity. When children (N = 111) were 7 months, baseline respiratory sinus arrhythmia (RSA), RSA withdrawal, and distress were collected during the Still Face Paradigm (SFP). Mothers' reports of infant regulation and orientation and maternal sensitivity were also collected at that time. Mothers' reports of toddlers' dysregulation were collected at 18 months. A set of hierarchical regressions indicated that low baseline RSA and less change in RSA from baseline to stressor predicted greater dysregulation at 18 months, but only for infants who experienced low maternal sensitivity. Baseline RSA and RSA withdrawal were not significantly associated with later dysregulation for infants with highly sensitive mothers. Infants who exhibited low distress during the SFP and who had lower regulatory and orienting abilities at 7 months had higher dysregulation at 18 months regardless of maternal sensitivity. Altogether, these results suggest that risk for dysregulation in toddlerhood has biobehavioral origins in infancy but may be buffered by sensitive caregiving.

Increased cardiac vagal tone in childhood-only, adolescent-only, and persistently antisocial teenagers: the mediating role of low heart rate

BACKGROUND

Cardiac vagal tone is an indicator of parasympathetic nervous system functioning, and there is increasing interest in its relation to antisocial behavior. It is unclear however whether antisocial individuals are characterized by increased or decreased vagal tone, and whether increased vagal tone is the source of the low heart rate frequently reported in antisocial populations.

METHODS

Participants consisted of four groups of community-dwelling adolescent boys aged 15.7 years: (1) controls, (2) childhood-only antisocial, (3) adolescent-only antisocial, and (4) persistently antisocial. Heart rate and vagal tone were assessed in three different conditions: rest, cognitive stressor, and social stressor.

RESULTS

All three antisocial groups had both lower resting heart rates and increased vagal tone compared to the low antisocial controls across all three conditions. Low heart rate partially mediated the relationship between vagal tone and antisocial behavior.

CONCLUSIONS

Results indicate that increased vagal tone and reduced heart rate are relatively broad risk factors for different developmental forms of antisocial behavior. Findings are the first to implicate vagal tone as an explanatory factor in understanding heart rate - antisocial behavior relationships. Future experimental work using non-invasive vagus nerve stimulation or heart rate variability biofeedback is needed to more systematically evaluate this conclusion.

Parasympathetic Nervous System Functioning Moderates the Associations between Callous-Unemotional Traits and Emotion Understanding Difficulties in Late Childhood

BACKGROUND

Callous-unemotional (CU) traits are characterized by low empathy, guilt, and prosociality, putting children at risk for lifespan antisocial behavior. Elevated CU traits have been linked separately to difficulties with emotion understanding (i.e., identifying emotional states of others) and disrupted parasympathetic nervous system (PNS) functioning. However, no study has investigated how PNS functioning and emotion understanding are jointly related to CU traits.

METHOD

We explored associations between CU traits, emotion understanding, and PNS functioning (indexed via respiratory sinus arrhythmia [RSA]) among children aged 7-10 years old (n = 55). We also tested whether deficits in emotion understanding differ across specific emotions (i.e., fear, pain, happiness, anger). Each child's RSA was continuously recorded while they watched a film that included emotionally evocative social interactions. To assess emotion understanding, children identified emotions replayed in 1s animations of scenes from the film. Parents reported on child CU traits, conduct problems, and demographic information.

RESULTS

Higher CU traits were related to lower emotion understanding (β = -0.43, p = 0.03). PNS activity during the film moderated this association (β = -0.47, p < 0.001), such that CU traits were associated with lower emotion understanding among children with mean (B = -0.01, t = -2.46, p = 0.02) or high (i.e., 1 SD > M; B = -0.02, t = -3.00, p < 0.001) RSA levels during the film, but not among children with low RSA levels (i.e., 1 SD < M; B = 0.00, t = -0.53, p = 0.60). Moreover, we found that the observed moderated associations are driven by deficits in fear, specifically.

CONCLUSIONS

The link between poorer emotion understanding, fear understanding in particular, and CU traits was attenuated for children who demonstrated patterns of PNS functioning consistent with attentional engagement while viewing the emotion stimuli.

The Impact of Callous-Unemotional Traits on Achievement, Behaviors, and Relationships in School: A Systematic Review

Disruptive behavior disorders (DBDs) are associated with significant academic, behavioral, and relationship challenges in the school setting. Children with co-occurring DBDs and callous-unemotional (CU) traits show a distinct pattern of early starting, chronic, and aggressive disruptive behavior and are resistant to traditional DBD interventions. There is growing evidence that CU traits have important consequences for children's school functioning. The purpose of this systematic review is to synthesize research on CU traits in school with a focus on academics, relationships, and behavior. We searched PsycINFO, PubMed, and Education Full-Text to identify 37 empirical studies that met inclusionary criteria. Findings suggest that CU traits are associated with poor academic performance, high levels of aggression and conduct problems, and difficulty forming relationships at school, often above and beyond the impact of DBDs alone. Findings and future directions are discussed including how the current study can support key stakeholders in promoting the success of students with elevated CU traits.

Predicting postpartum depressive symptoms by evaluating self-report autonomic nervous system reactivity during pregnancy

OBJECTIVE

Altered self-reported autonomic reactivity is associated with worse mental health in the general population. Although dysfunctional changes in ANS during pregnancy have been investigated in relation to depressive symptoms, no studies addressed the relationship between self-report autonomic reactivity during pregnancy and depressive symptoms after the delivery. The present study aimed to assess the impact of prepartum self-reported autonomic reactivity on the development of postpartum depressive symptoms.

METHODS

In this longitudinal study, 170 women were assessed during pregnancy (i.e., second or third trimester) and after childbirth (i.e., one month after the delivery). Self-reported autonomic reactivity was assessed through the Body Perception Questionnaire - Short Form that evaluates the autonomic functions related to organs above (i.e., supradiaphragmatic reactivity) and below (i.e., subdiaphragmatic reactivity) the diaphragm. In addition, prepartum and postpartum depressive symptoms were evaluated using the Patient Health Questionnaire - 9.

RESULTS

Findings showed that higher prepartum supradiaphragmatic reactivity predicted higher depressive symptoms in the postpartum period (β = 0.112, p = 0.009) after controlling for prepartum depressive symptomatology and other potential covariates.

CONCLUSIONS

Evaluation of self-reported autonomic activity may be a useful tool to identify antenatally women at risk of postpartum depressive symptoms. Future studies are needed to evaluate the effectiveness of interventions aimed at reducing the threat-responsive autonomic reactivity at rest and improving adaptive autonomic regulation to prevent postpartum depression.

Promoting Empathy and Affiliation in Relationships (PEAR) study: protocol for a longitudinal study investigating the development of early childhood callous-unemotional traits

INTRODUCTION

Children with callous-unemotional (CU) traits are at high lifetime risk of antisocial behaviour. Low affiliation (ie, social bonding difficulties) and fearlessness (ie, low threat sensitivity) are proposed risk factors for CU traits. Parenting practices (eg, harshness and low warmth) also predict risk for CU traits. However, few studies in early childhood have identified attentional or physiological markers of low affiliation and fearlessness. Moreover, no studies have tested whether parenting practices are underpinned by low affiliation or fearlessness shared by parents, which could further shape parent-child interactions and exacerbate risk for CU traits. Addressing these questions will inform knowledge of how CU traits develop and isolate novel parent and child targets for future specialised treatments for CU traits.

METHODS AND ANALYSIS

The Promoting Empathy and Affiliation in Relationships (PEAR) study aims to establish risk factors for CU traits in children aged 3-6 years. The PEAR study will recruit 500 parent-child dyads from two metropolitan areas of the USA. Parents and children will complete questionnaires, computer tasks and observational assessments, alongside collection of eye-tracking and physiological data, when children are aged 3-4 (time 1) and 5-6 (time 2) years. The moderating roles of child sex, race and ethnicity, family and neighbourhood disadvantage, and parental psychopathology will also be assessed. Study aims will be addressed using structural equation modelling, which will allow for flexible characterisation of low affiliation, fearlessness and parenting practices as risk factors for CU traits across multiple domains.

ETHICS AND DISSEMINATION

Ethical approval was granted by Boston University (#6158E) and the University of Pennsylvania (#850638). Results will be disseminated through conferences and open-access publications. All study and task materials will be made freely available on lab websites and through the Open Science Framework (OSF).

Psychometric Properties, Factor Structure, and Validity of the Sensitivity to Threat and Affiliative Reward Scale in Children and Adults

Callous-Unemotional (CU) traits identify children at high risk of antisocial behavior. A recent theoretical model proposed that CU traits arise from low sensitivity to threat and affiliation. To assess these dimensions, we developed the parent- and self-reported Sensitivity to Threat and Affiliative Reward Scale (STARS) and tested its psychometric properties, factor structure, and construct validity. Samples 1 (N =3 03; age 3-10; United States) and 2 (N = 854 age 5-9; Spain) were children and Sample 3 was 514 young adults (Mage = 19.89; United States). In Sample 1, differential item functioning and item response theory techniques were used to identify the best-performing items from a 64-item pool, resulting in 28 items that functioned equivalently across age and gender. Factor analysis indicated acceptable fit for the theorized two-factor structure with separate threat and affiliation factors in all three samples, which showed predictive validity in relation to CU traits in children and psychopathic traits in young adults.

Examining the Relations Between Children's Vagal Flexibility Across Social Stressor Tasks and Parent- and Clinician-Rated Anxiety Using Baseline Data from an Early Intervention for Inhibited Preschoolers

Early behavioral inhibition (BI) is a known risk factor for later anxiety disorder. Variability in children's parasympathetic nervous system (PNS) functioning may provide insight into the substantial heterogeneity in anxiety outcomes for children high in BI. However, gaps persist due to an over-reliance on static measures of functioning, which limits our ability to leverage PNS functioning to identify risk for anxiety. We address these gaps using baseline data from an early intervention study of inhibited preschoolers by characterizing vagal flexibility (VF), an index of non-linear change in PNS functioning, across social stressor tasks and by examining the associations between VF and anxiety. One hundred and fifty-one parents and their 3.5- to 5-year-old children were selected on the basis of BI to participate in an early intervention program (ClinicalTrials.gov registration: NCT02308826). A structural equation modeling framework was used to model children's VF across tasks designed to mimic exposure to novel social interactions and to test the predictive links between VF and anxiety. Children who showed less VF, characterized by less suppression and flatter recovery, were rated by both parents and clinicians as more anxious. Moreover, a multiple group model showed that children meeting diagnostic criteria for social anxiety disorder demonstrated significantly less VF across social stressor tasks. Among inhibited youth, reduced VF is a risk factor for anxiety and may reflect an individual's reduced capacity to actively cope with external demands. Study results contribute to our understanding of the regulatory processes underlying risk for anxiety in early childhood.

Unique Contributions of Maternal Prenatal and Postnatal Emotion Dysregulation on Infant Respiratory Sinus Arrhythmia

Prenatal intrauterine exposures and postnatal caregiving environments may both shape the development of infant parasympathetic nervous system (PNS) activity. However, the relative contributions of prenatal and postnatal influences on infant respiratory sinus arrhythmia (RSA)-an index of PNS functioning-are relatively unknown. We examined whether prenatal and postnatal maternal emotion dysregulation, a transdiagnostic construct that spans mental health diagnoses, were independently related to infant RSA trajectories during a social stressor, the still-face paradigm. Our sample included 104 mothers and their 7-month-old infants. Maternal emotion dysregulation was measured with the Difficulties in Emotion Regulation Scale during the 3rd trimester of pregnancy and again at a 7-month postpartum laboratory visit. Infant RSA was recorded during the still-face paradigm. Only postnatal maternal emotion dysregulation was associated with infant RSA. Specifically, high postnatal emotion dysregulation was associated with a blunted (i.e., dampened reactivity and recovery) infant RSA response profile. Infant sex did not moderate the associations between maternal emotion dysregulation and infant RSA. Findings suggest that postnatal interventions to promote effective maternal emotion regulation may reduce risk for infants' dysregulated psychophysiological stress responses.

Context is key: Parasympathetic regulation in the classroom differentially predicts preschoolers' socially competent behaviors

Research shows that children's early social competence predicts their later academic and interpersonal success. Accordingly, early childhood education programs increasingly aim to evaluate and support children's social skill development. Despite ample theoretical and empirical work demonstrating the role of the parasympathetic nervous system (PNS) in supporting neurophysiological processes that underlie social behaviors, no study has explicitly tested whether the assessment of PNS activity in childhood educational settings provides insight into children's social functioning. The current study addresses this gap by examining the influence of context-specific PNS regulation, assessed via respiratory sinus arrhythmia (RSA), in predicting preschool children's socially competent behavior toward peers in the classroom. Results showed that: (1) RSA withdrawal (e.g., decreases relative to a baseline task) during unstructured classroom activities predicted children's socially competent behaviors during these unstructured activities but not during structured activities, whereas (2) withdrawal during structured classroom activities predicted children's socially competent behaviors during structured activities. These results indicate that PNS activity makes context-specific contributions to children's social behaviors and highlight the importance of assessing neurophysiological regulation in context.

Psychophysiological underpinnings of proactive and reactive aggression in young men and women

Reactive aggression is posited to occur as a result of hypersensitivity to threat, whereas fearlessness may drive proactive aggression. This study aimed to test if physiological fear reactivity differentially relates to self-report reactive and proactive aggression using immersive virtual reality fear (VR) induction. We collected subjective fear ratings and sympathetic (SNS; skin conductance) and parasympathetic (PNS; respiratory sinus arrhythmia) nervous system reactivity during an interactive VR horror video. Results showed that for men and women, reactive aggression was related to heightened SNS fear reactivity. For men, proactive aggression was related to hypoarousal of the PNS and SNS (coinhibition) during fear induction, whereas augmented PNS was related to proactive aggression in women. These results support the fearlessness hypothesis for proactive aggression in men, but this does not replicate in women. By contrast, hypersensitivity to fear is related to reactive aggression for both men and women.

Heart-wired to be cold? Exploring cardiac markers of callous-unemotional traits in incarcerated offenders

Elevated callous-unemotional (CU) traits have been repeatedly identified in a subgroup of offenders that displays severe antisocial behavior; establishing physiological markers may help improve early identification and treatment efforts. This study examines to what extent baseline-resting heart rate (HR) and heart rate variability (HRV) can be used as markers of CU in incarcerated juvenile and adult offenders. CU traits were assessed using the Inventory of Callous-Unemotional traits. Results of the multiple hierarchical regression tests indicated that there was a small yet significant positive association between baseline HR and CU and negative association between HRV and CU in juvenile offenders with medium model effect sizes (R² = 0.115 for HR-CU; R² = 0.126 for HRV-CU). The cardiac markers were unrelated to CU in adult offenders. These findings are important because they demonstrate that impaired cardiac autonomic activity is related to CU traits in juveniles, suggesting that socioemotional processing difficulties should be considered in understanding these deficits. Future research should be conducted in large samples, under reactive and static conditions, while including cardiac covariates, to get more clarity on the interplay between biological systems and behavioral expression.

Characterizing change in vagal tone during the first three years of life: A systematic review and empirical examination across two longitudinal samples

Functioning of the parasympathetic nervous system (PNS), most often indexed by respiratory sinus arrhythmia (RSA), influences the volitional, cognitively-mediated forms of self-regulation across development. However, despite its clear relevance to children's self-regulation, and its utility as a transdiagnostic biomarker of emotion dysregulation and psychopathology, the ontogeny of vagal tone under conditions of homeostasis across infancy and early childhood is not well understood. The current research is comprised of two complementary studies. The first aims to address this gap by conducting a systematic review of the literature which has assessed resting RSA in the first three years of life. The second study uses data from two diverse, longitudinal datasets (n = 203 and n = 370) to model change in RSA from infancy to toddlerhood. Results from a systematic review of 62 studies meeting inclusion criteria suggest that measures of resting RSA increase over time and demonstrate moderate stability across infancy, toddlerhood, and preschool ages. Results from a series of models fit to longitudinal data in study two suggest that baseline RSA is characterized by stable increases across infancy and early childhood. Moreover, although there was equivocal evidence for individual variability in trajectories of RSA, the findings suggest that the individual differences in resting RSA may become entrenched in early life based on observed significant variance in growth model intercepts. In all, the current study contributes to our understanding of the developmental trajectories of baseline RSA across infancy and early childhood and should support future research examining links between children's parasympathetic regulation and their adjustment in early life.

Autonomic Nervous System Inflexibility During Parent-child Interactions is Related to Callous-unemotional Traits in Youth Aged 10-14 Years Old

Youth with callous-unemotional (CU) traits are at high risk for aggression and antisocial behavior. Extant literature suggests that CU traits are related to abnormal autonomic responses to negatively-valenced emotional stimuli, although few studies have tested autonomic responding specifically during social interactions. To address this knowledge gap, the current study tested whether CU traits were related to autonomic activity, assessed via respiratory sinus arrhythmia (RSA), during several parent-child interaction tasks designed to provoke negative emotion. The sample was 162 clinically referred youth (M age = 12.03, SD = .92; 47% female). Using piecewise latent growth models, we estimated individual differences in RSA during three semi-structured social interaction tasks (reading aloud to a parent and research assistant; a recovery period from the reading task; and a parent-child conflict discussion) and tested whether CU traits were related to patterns of RSA responding across tasks. Overall, youth showed expected RSA decreases during the reading period, increases in RSA during recovery, and further decreases during the conflict discussion. However, youth with clinically-elevated CU traits had a different pattern of RSA change across tasks, such that CU traits were related to significantly less RSA change during reading and recovery. Findings suggest that less RSA engagement during social interactions and less RSA recovery may be a biomarker of CU traits. Future research is needed to examine whether this inflexibility contributes to the development of CU traits beginning early in childhood.

Neural and Self-Report Markers of Reassurance: A Generalized Additive Modelling Approach

Research has shown that engaging in self-reassurance, a compassionately motivated cognitive relating style, can down-regulate neural markers of threat and pain. Whilst important, the relationship between neural and self-report markers of reassurance are largely unknown. Here we analyzed previously published fMRI data which measured neural responses when participants engaged in self-reassurance toward a mistake, setback, or failure. Within the present paper, we identified correlations between regions of interest extracted during self-reassurance with fMRI and self-report data. Using generalized additive modelling, we show that participants with greater inadequate forms of self-criticism exhibited greater neural activation within the medial prefrontal cortex (MPFC) and anterior insula (AI). Furthermore, a relationship between greater fears of expressing compassion to the self and neural activation within the MPFC returned non-significant after correction for multiple comparisons. No significant relationships were observed between brain activation and hated and reassuring forms of self-criticism. Our results identify preliminary evidence for neural activity during self-reassurance as correlated with self-report markers, and we outline a method for modelling neural and self-report data which can be applied to future studies in compassion science, particularly with a clinical sample.