Anxious parents show higher physiological synchrony with their infants

A context-dependent model of resilient functioning after childhood maltreatment-the case for flexible biobehavioral synchrony

Many children who experience childhood adversity, whether in the form of threat or deprivation, develop adaptive competencies that lead to resilient functioning. Still, research has not succeeded in accurately predicting the level of resilient functioning by any kind of biomarkers, likely because it has sidelined the flexibility inherent in a construct that is situationally and developmentally variable. Whilst recent research acknowledges the importance of redefining resilience in order to reflect its dynamic nature after adversity, evidence for specific behaviors that are developmentally adaptive and dynamic throughout the lifespan is limited. We here propose a model in which resilient functioning is crucially dependent on the individual's capability to flexibly synchronize with and segregate from another's cognitive-affective, behavioral, and physiological states, known as 'biobehavioral synchrony'. Such an adaptive interpersonal skill is rooted in (a) the early caregiving experience and its regulatory effects on an individual's physiological stress reactivity, as well as (b) the development of self-other distinction which can be affected by childhood maltreatment. Bridging the gap between accounts of flexible resilient functioning and the latest thinking in biobehavioral synchrony, we will review behavioral and neurobiological evidence that threat and deprivation in childhood interfere with the development of dynamic, context-sensitive boundaries between self and other, mediated by the (right) tempo-parietal junction (a central neural hub for interpersonal synchronization), which puts the individual at risk for affective fusion or cut-off from others' arousal states. Our proposed model charts a path for investigating the differential effects of maltreatment experiences and mechanisms for intergenerational transmission of non-sensitive caregiving. We conclude with metrics, data analysis methods, and strategies to facilitate flexible biobehavioral synchrony.

Maternal heart rate variability at 3-months postpartum is associated with maternal mental health and infant neurophysiology

Previous research has demonstrated a critical link between maternal mental health and infant development. However, there is limited understanding of the role of autonomic regulation in postpartum maternal mental health and infant outcomes. In the current study, we tested 76 mother-infant dyads from diverse socioeconomic backgrounds when infants were 3-months of age. We recorded simultaneous ECG from dyads while baseline EEG was collected from the infant; ECG heart rate variability (HRV) and EEG theta-beta ratio and alpha asymmetry were calculated. Dyadic physiological synchrony was also analyzed to better understand the role of autonomic co-regulation. Results demonstrated that lower maternal HRV was associated with higher self-reported maternal depression and anxiety. Additionally, mothers with lower HRV had infants with lower HRV. Maternal HRV was also associated with higher infant theta-beta ratios, but not alpha asymmetry. Exploratory analyses suggested that for mother-infant dyads with greater physiological synchrony, higher maternal HRV predicted increased infant theta-beta ratio via infant HRV. These findings support a model in which maternal mental health may influence infant neurophysiology via alterations in autonomic stress regulation and dyadic physiological co-regulation.

Interpersonal emotion regulation and physiological synchrony: cognitive reappraisal versus expressive suppression

The present study aimed to explore the effectiveness of two typical intrapersonal strategies (cognitive reappraisal, CR; expressive suppression, ES) on interpersonal emotion regulation (IER), and uncover the physiological synchrony pattern underlying this. A sample of 90 friend dyads (N = 180) was randomly assigned to the CR, the ES, or the control group. In each dyad, the target underwent a negative emotional task (induce sadness by recalling a negative event), and the regulator was assigned to implement the CR strategy, the ES strategy, or no action to down-regulate the targets' negative emotions. Self-reported results showed that compared to the control group, both CR and ES strategies decreased the targets' negative emotions, and increased the targets' positive emotions, indicating a successful IER effect. And the ECG results revealed that relative to the control condition, both CR and ES strategies evoked stronger physiological synchrony (heart rate synchrony and heart rate variation synchrony) during the emotion regulation stage of IER. Overall, these findings demonstrated the similar efficacy of reappraisal and suppression strategies implemented by the regulators to improve the targets' negative emotions, and suggested that the physiological synchrony might have an important relational meaning during the IER process.

How and Why People Synchronize: An Integrated Perspective

Academic AbstractInterpersonal synchrony, the alignment of behavior and/or physiology during interactions, is a pervasive phenomenon observed in diverse social contexts. Here we synthesize across contexts and behaviors to classify the different forms and functions of synchrony. We provide a concise framework for classifying the manifold forms of synchrony along six dimensions: periodicity, discreteness, spatial similarity, directionality, leader-follower dynamics, and observability. We also distill the various proposed functions of interpersonal synchrony into four interconnected functions: reducing complexity and improving understanding, accomplishing joint tasks, strengthening social connection, and influencing partners' behavior. These functions derive from first principles, emerge from each other, and are accomplished by some forms of synchrony more than others. Effective synchrony flexibly adapts to social goals and more synchrony is not always better. Our synthesis offers a shared framework and language for the field, allowing for better cross-context and cross-behavior comparisons, generating new hypotheses, and highlighting future research directions.

The association of maternal-infant interactive behavior, dyadic frontal alpha asymmetry, and maternal anxiety in a smartphone-adapted still face paradigm

Mother-infant interactions form a strong basis for emotion regulation development in infants. These interactions can be affected by various factors, including maternal postnatal anxiety. Electroencephalography (EEG) hyperscanning allows for simultaneous assessment of mother-infant brain-to-behavior association during stressful events, such as the still-face paradigm (SFP). This study aimed at investigating dyadic interactive behavior and brain-to-behavior association across SFP and identifying neural correlates of mother-infant interactions in the context of maternal postnatal anxiety. We measured frontal alpha asymmetry (FAA), a physiological correlate of emotion regulation and a potential marker of risk for psychopathology. To emulate real-life interactions, EEG and behavioral data were collected from 38 mother-infant dyads during a smartphone-adapted dual-SFP. Although the behavioral data showed a clear still-face effect for the smartphone-adapted SFP, this was not reflected in the infant or maternal FAA. Brain-to-behavior data showed higher infant negative affect being associated with more infant leftward FAA during the still-face episodes. Finally, mothers with higher postnatal anxiety showed more right FAA during the first still-face episode, suggesting negative affectivity and a need to withdraw from the situation. Our results form a baseline for further research assessing the effects of maternal postnatal anxiety on infants' FAA and dyadic interactive behavior.

Visualizing the invisible tie: Linking parent-child neural synchrony to parents' and children's attachment representations

It is a central tenet of attachment theory that individual differences in attachment representations organize behavior during social interactions. Secure attachment representations also facilitate behavioral synchrony, a key component of adaptive parent-child interactions. Yet, the dynamic neural processes underlying these interactions and the potential role of attachment representations remain largely unknown. A growing body of research indicates that interpersonal neural synchrony (INS) could be a potential neurobiological correlate of high interaction and relationship quality. In this study, we examined whether interpersonal neural and behavioral synchrony during parent-child interaction is associated with parent and child attachment representations. In total, 140 parents (74 mothers and 66 fathers) and their children (age 5-6 years; 60 girls and 80 boys) engaged in cooperative versus individual problem-solving. INS in frontal and temporal regions was assessed with functional near-infrared spectroscopy hyperscanning. Attachment representations were ascertained by means of the Adult Attachment Interview in parents and a story-completion task in children, alongside video-coded behavioral synchrony. Findings revealed increased INS during cooperative versus individual problem solving across all dyads (𝛸2(2) = 9.37, p = 0.009). Remarkably, individual differences in attachment representations were associated with INS but not behavioral synchrony (p > 0.159) during cooperation. More specifically, insecure maternal attachment representations were related to higher mother-child INS in frontal regions (𝛸2(3) = 9.18, p = 0.027). Conversely, secure daughter attachment representations were related to higher daughter-parent INS within temporal regions (𝛸2(3) = 12.58, p = 0.006). Our data thus provide further indication for INS as a promising correlate to probe the neurobiological underpinnings of attachment representations in the context of early parent-child interactions. RESEARCH HIGHLIGHTS: We assessed attachment representations using narrative measures and interpersonal neural synchrony (INS) during parent-child problem-solving. Dyads including mothers with insecure attachment representations showed higher INS in left prefrontal regions. Dyads including daughters with secure attachment representations showed higher INS in right temporo-parietal regions. INS is a promising correlate to probe the neurobiological underpinnings of attachment representations in the context of parent-child interactions, especially within the mutual prediction framework.

Childbirth-related posttraumatic stress disorder: definition, risk factors, pathophysiology, diagnosis, prevention, and treatment

Psychological birth trauma and childbirth-related posttraumatic stress disorder represent a substantial burden of disease with 6.6 million mothers and 1.7 million fathers or co-parents affected by childbirth-related posttraumatic stress disorder worldwide each year. There is mounting evidence to indicate that parents who develop childbirth-related posttraumatic stress disorder do so as a direct consequence of a traumatic childbirth experience. High-risk groups, such as those who experience preterm birth, stillbirth, or preeclampsia, have higher prevalence rates. The main risks include antenatal factors (eg, depression in pregnancy, fear of childbirth, poor health or complications in pregnancy, history of trauma or sexual abuse, or mental health problems), perinatal factors (eg, negative subjective birth experience, operative birth, obstetrical complications, and severe maternal morbidity, as well as maternal near misses, lack of support, dissociation), and postpartum factors (eg, depression, postpartum physical complications, and poor coping and stress). The link between birth events and childbirth-related posttraumatic stress disorder provides a valuable opportunity to prevent traumatic childbirths and childbirth-related posttraumatic stress disorder from occurring in the first place. Childbirth-related posttraumatic stress disorder is an extremely distressing mental disorder and has a substantial negative impact on those who give birth, fathers or co-parents, and, potentially, the whole family. Still, a traumatic childbirth experience and childbirth-related posttraumatic stress disorder remain largely unrecognized in maternity services and are not routinely screened for during pregnancy and the postpartum period. In fact, there are gaps in the evidence on how, when, and who to screen. Similarly, there is a lack of evidence on how best to treat those affected. Primary prevention efforts (eg, screening for antenatal risk factors, use of trauma-informed care) are aimed at preventing a traumatic childbirth experience and childbirth-related posttraumatic stress disorder in the first place by eliminating or reducing risk factors for childbirth-related posttraumatic stress disorder. Secondary prevention approaches (eg, trauma-focused psychological therapies, early psychological interventions) aim to identify those who have had a traumatic childbirth experience and to intervene to prevent the development of childbirth-related posttraumatic stress disorder. Tertiary prevention (eg, trauma-focused cognitive behavioural therapy and eye movement desensitization and reprocessing) seeks to ensure that people with childbirth-related posttraumatic stress disorder are identified and treated to recovery so that childbirth-related posttraumatic stress disorder does not become chronic. Adequate prevention, screening, and intervention could alleviate a considerable amount of suffering in affected families. In light of the available research on the impact of childbirth-related posttraumatic stress disorder on families, it is important to develop and evaluate assessment, prevention, and treatment interventions that target the birthing person, the couple dyad, the parent-infant dyad, and the family as a whole. Further research should focus on the inclusion of couples in different constellations and, more generally, on the inclusion of more diverse populations in diverse settings. The paucity of national and international policy guidance on the prevention, care, and treatment of psychological birth trauma and the lack of formal psychological birth trauma services and training, highlight the need to engage with service managers and policy makers.

Interparental Positivity Spillover Theory: How Parents' Positive Relational Interactions Influence Children

Interparental interactions have an important influence on child well-being and development. Yet prior theory and research have primarily focused on interparental conflict as contributing to child maladjustment, which leaves out the critical question of how interparental positive interactions-such as expressed gratitude, capitalization, and shared laughter-may benefit child growth and development. In this article, we integrate theory and research in family, relationship, and affective science to propose a new framework for understanding how the heretofore underexamined positive interparental interactions influence children: interparental positivity spillover theory (IPST). IPST proposes that, distinct from the influence of conflict, interparental positive interactions spill over into children's experiences in the form of their (a) experience of positive emotions, (b) beneficially altered perceptions of their parents, and (c) emulation of their parents' positive interpersonal behaviors. This spillover is theorized to promote beneficial cognitive, behavioral, social, and physiological outcomes in children in the short term (i.e., immediately after a specific episode of interparental positivity, or on a given day) as well as cumulatively across time. As a framework, IPST generates a host of novel and testable predictions to guide future research, all of which have important implications for the mental health, well-being, and positive development of children and families.

Inter-brain synchrony during mother-infant interactive parenting in 3-4-month-old infants with and without an elevated likelihood of autism spectrum disorder

Maternal bonding for mammalian infants is critical for their survival. Additionally, it is important for human infants' development into social creatures. However, despite the ample neurobiological evidence of attachment for the mother's brain, the interplay of this system in infants is poorly understood. We aimed to identify the neural substrates of synchrony in mothers and infants under three interactive conditions and compare the differences between groups with (n = 16) and without (n = 71) an elevated likelihood of autism spectrum disorder by examining the inter-brain synchrony between mothers and their 3-4-month-old infants. Mother-infant hyperscanning with functional near-infrared spectroscopy was performed during breastfeeding and while each of the mother and experimenter was holding the infants. The results showed almost no group differences, with both groups demonstrating the strongest inter-brain coupling for breastfeeding. The cerebral foci underlying these couplings differed between mothers and infants: the ventral prefrontal cortex, focusing on the right orbitofrontal cortex, in the mother and the left temporoparietal junction in the infant were chiefly involved in connecting the two brains. Furthermore, these synchronizations revealed many significant correlations with behavioral measures, including subsequent language development. The maternal reward-motivational system and the infant's elementary mentalization system seem to underlie mother-infant coupling during breastfeeding.

Parent-infant affect synchrony during social and solo play

While mother-infant affect synchrony has been proposed to facilitate the early development of social understanding, most investigations into affect synchrony have concentrated more on negative than positive affect. We analysed affect sharing during parent-infant object play, comparing positive and negative affect, to examine how it is modulated by shared playful activity. Mother-infant dyads (N = 20, average infant age 10.7 months) played together (social) or separately (solo) using an object. Both participants increased positive affect during social play as compared with solo play. Positive affect synchrony also increased during social play compared with solo play, whereas negative affect synchrony did not differ. Closer examination of the temporal dynamics of affect changes showed that infants' shifts to positive affect tended to occur contingently in response to their mothers', whereas mothers' shifts to negative affect followed their infants'. Further, during social play, positive affect displays were more long-lived while negative more short-lived. While our sample was small and from a homogeneous population (e.g. white, highly educated parents), limiting the implications of the findings, these results demonstrate that maternal active engagement in playful interaction with her infant affords, increases, and extends infant positive affect and parent-infant positive affect synchrony, providing insights into how the social context modulates infants' affective experiences. This article is part of a discussion meeting issue 'Face2face: advancing the science of social interaction'.

Maternal anxiety symptoms associated with increased behavioral synchrony in the early postnatal period

The presence of perinatal mood and anxiety disorders has typically been associated with decreases in the quality of mother-infant interactions. However, maternal anxiety symptoms during the postpartum period have been less studied than other mental health disorders like depression. In the current study, we examined associations among symptoms of maternal anxiety, maternal perceived stress, and mother-infant behavioral synchrony in the early postnatal period. Eighty-one mother-infant dyads participated in this study when the infants were 3 months old. Surveys were given to obtain demographic information and current maternal mental health symptoms, and dyads completed a 5-min free-play task to measure behavioral synchrony. Results indicated that maternal anxiety symptoms were positively associated with behavioral synchrony, but only for mothers reporting moderate levels of perceived stress. These findings highlight the differential impact of maternal postpartum mental health on behavioral synchrony and suggest that higher maternal anxiety symptoms during the postnatal period may play an adaptive role in fostering more dynamic mother-infant interactions.

Father-child physiological concordance on two timescales is differentially associated with paternal characteristics

Conceptual work on interpersonal physiology suggests that the dynamic concordance between two person's physiological arousal may transpire on multiple timescales, and the timescale on which it unfolds may determine its psychological significance. The current study tested this hypothesis in the context of parent-child interaction by examining whether the concordance in their cardiac arousal on two timescales was differentially associated with parental characteristics. Using data from 98 fathers and their 3- to 5-year-old children during a task designed to frustrate young children, results indicated that the associations between cardiac concordance and fathers' self-reported parenting hassles emerged for the slower timescale (concordant increasing trends in arousal), whereas concordance on the faster timescale (concordant second-by-second reactivity) was associated with fathers' emotional clarity. Findings suggest that there may be multiple layers of concordant patterns in the dynamic associations between fathers' and children's cardiac arousal, which unfold on different timescales and bear different psychological significance.

Oscillatory entrainment to our early social or physical environment and the emergence of volitional control

An individual's early interactions with their environment are thought to be largely passive; through the early years, the capacity for volitional control develops. Here, we consider: how is the emergence of volitional control characterised by changes in the entrainment observed between internal activity (behaviour, physiology and brain activity) and the sights and sounds in our everyday environment (physical and social)? We differentiate between contingent responsiveness (entrainment driven by evoked responses to external events) and oscillatory entrainment (driven by internal oscillators becoming temporally aligned with external oscillators). We conclude that ample evidence suggests that children show behavioural, physiological and neural entrainment to their physical and social environment, irrespective of volitional attention control; however, evidence for oscillatory entrainment beyond contingent responsiveness is currently lacking. Evidence for how oscillatory entrainment changes over developmental time is also lacking. Finally, we suggest a mechanism through which periodic environmental rhythms might facilitate both sensory processing and the development of volitional control even in the absence of oscillatory entrainment.

Vocalization and physiological hyperarousal in infant-caregiver dyads where the caregiver has elevated anxiety

Co-regulation of physiological arousal within the caregiver-child dyad precedes later self-regulation within the individual. Despite the importance of unimpaired self-regulatory development for later adjustment outcomes, little is understood about how early co-regulatory processes can become dysregulated during early life. Aspects of caregiver behavior, such as patterns of anxious speech, may be one factor influencing infant arousal dysregulation. To address this, we made day-long, naturalistic biobehavioral recordings in home settings in caregiver-infant dyads using wearable autonomic devices and miniature microphones. We examined the association between arousal, vocalization intensity, and caregiver anxiety. We found that moments of high physiological arousal in infants were more likely to be accompanied by high caregiver arousal when caregivers had high self-reported trait anxiety. Anxious caregivers were also more likely to vocalize intensely at states of high arousal and produce intense vocalizations that occurred in clusters. High-intensity vocalizations were associated with more sustained increases in autonomic arousal for both anxious caregivers and their infants. Findings indicate that caregiver vocal behavior differs in anxious parents, cooccurs with dyadic arousal dysregulation, and could contribute to physiological arousal transmission. Implications for caregiver vocalization as an intervention target are discussed.

Vocal communication is tied to interpersonal arousal coupling in caregiver-infant dyads

It has been argued that a necessary condition for the emergence of speech in humans is the ability to vocalise irrespective of underlying affective states, but when and how this happens during development remains unclear. To examine this, we used wearable microphones and autonomic sensors to collect multimodal naturalistic datasets from 12-month-olds and their caregivers. We observed that, across the day, clusters of vocalisations occur during elevated infant and caregiver arousal. This relationship is stronger in infants than caregivers: caregivers vocalisations show greater decoupling with their own states of arousal, and their vocal production is more influenced by the infant's arousal than their own. Different types of vocalisation elicit different patterns of change across the dyad. Cries occur following reduced infant arousal stability and lead to increased child-caregiver arousal coupling, and decreased infant arousal. Speech-like vocalisations also occur at elevated arousal, but lead to longer-lasting increases in arousal, and elicit more parental verbal responses. Our results suggest that: 12-month-old infants' vocalisations are strongly contingent on their arousal state (for both cries and speech-like vocalisations), whereas adults' vocalisations are more flexibly tied to their own arousal; that cries and speech-like vocalisations alter the intra-dyadic dynamics of arousal in different ways, which may be an important factor driving speech development; and that this selection mechanism which drives vocal development is anchored in our stress physiology.

Maternal perinatal anxiety and neural responding to infant affective signals: Insights, challenges, and a road map for neuroimaging research

Anxiety symptoms are common among women during pregnancy and the postpartum period, potentially having detrimental effects on both mother and child's well-being. Perinatal maternal anxiety interferes with a core facet of adaptive caregiving: mothers' sensitive responsiveness to infant affective communicative 'cues.' This review summarizes the current research on the neural correlates of maternal processing of infant cues in the presence of perinatal anxiety, outlines its limitations, and offers next steps to advance future research. Functional neuroimaging studies examining the neural circuitry involved in, and electrophysiological studies examining the temporal dynamics of, processing infant cues during pregnancy and postpartum are reviewed. Studies have generally indicated mixed findings, although emerging themes suggest that anxiety may be implicated in several stages of processing infant cues- detection, interpretation, and reaction- contingent upon cue valence. Limitations include inconsistent designs, lack of differentiation between anxiety and depression symptoms, and limited consideration of parenting-specific (versus domain-general) anxiety. Future studies should incorporate longitudinal investigation of multiple levels of analysis spanning neural, cognitive, and observed aspects of sensitive caregiving.