Annual Research Review: 'There, the dance is - at the still point of the turning world' - dynamic systems perspectives on coregulation and dysregulation during early development

'Shared efforts, brighter smiles': a protocol for a randomised controlled study on the effectiveness of a parent-child orofacial myofunctional therapy programme post-adenoidectomy

INTRODUCTION

Adenoid hypertrophy has a high prevalence in children, often causing early orofacial muscle dysfunction that worsens facial deformities over time. While adenoidectomy (AT) alleviates airway obstruction, it only partially addresses the condition, leaving persistent neuromuscular habits. Orofacial myofunctional therapy is necessary for post-AT recovery but faces challenges such as poor adherence and ineffective parent-child communication. Dyadic interventions, which actively involve both parents and children, have shown advantages in improving treatment adherence and enhancing orofacial muscle function. Evidence suggests that dyadic intervention addresses both the child's recovery needs and the caregiving capacity of parents, offering a more comprehensive solution for long-term intervention. Therefore, our team developed a parent-child dyadic orofacial myofunctional therapy (PCD-OMT) programme, offering insights into its potential application in paediatric healthcare to support comprehensive family-centred care.

METHOD AND ANALYSIS

This two-arm, parallel-design, randomised controlled trial will recruit 80 dyads whose children performed AT from two hospitals in Qingdao, China. Dyads will be randomly allocated to two arms. Dyads randomly assigned to the intervention group will receive the PCD-OMT programme. Dyads randomly assigned to the control group will receive regular care. The primary outcomes are orofacial myofunction in children and parental care abilities. The secondary outcomes are children's engagement and parental functioning. A feasibility and acceptability process will be employed to evaluate the viability in clinical practice. Outcomes will be collected at three checkpoints: baseline (T0), postintervention (T1) and after a 12-week follow-up phase (T2).

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Medical College of Qingdao University (QDU-HEC-2023216). The results will be published in peer-reviewed publications and presented in international conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2400091466.

Finding order in chaos: influences of environmental complexity and predictability on development

Environments are dynamic and complex. Some children experience more predictable early life environments than others. Here, we consider how moment-by-moment complexity and predictability in our early environments influence development. New studies using wearable sensors are quantifying this environmental variability at a fine temporal resolution across hierarchically structured physical and social features. We identify three types of predictability: periodicities ('at X time intervals, Y happens'), stability ('given statex, statex+1 is known'), and contingency ('when I do X, Y happens'). We discuss how the temporal dynamics of environments may differ between individuals and the diverse developmental neural pathways through which this may influence outcomes, such as central nervous system (CNS) arousal and executive control. Finally, we discuss practical consequences and directions for future research.

Needing to shout to be heard? Caregiver under-responsivity and disconnection between vocal signaling and autonomic arousal in infants from chaotic households

Children raised in chaotic households show affect dysregulation during later childhood. To understand why, we took day-long home recordings using microphones and autonomic monitors from 74 12-month-old infant-caregiver dyads (40% male, 60% white, data collected between 2018 and 2021). Caregivers in low-Confusion Hubbub And Order Scale (chaos) households responded to negative affect infant vocalizations by changing their own arousal and vocalizing in response; but high-chaos caregivers did not, whereas infants in low-chaos households consistently produced clusters of negative vocalizations around peaks in their own arousal, high-chaos infants did not. Their negative vocalizations were less tied to their own underlying arousal. Our data indicate that, in chaotic households, both communicating and responding are atypical: infants are not expressing their levels of arousal, and caregivers are under-responsive to their infants' behavioral signals.

Dyadic resilience after postpartum depression: The protective role of mother-infant respiratory sinus arrhythmia synchrony during play for maternal and child mental health across early childhood

Coordination in mothers' and their infants' parasympathetic nervous system functioning (i.e., respiratory sinus arrhythmia [RSA] synchrony) specifically during playful interactions may promote resilience against exposure to postpartum depressive symptoms (PPD), for both members of the dyad. To test biobehavioral synchrony theory-derived hypotheses, we evaluated whether positive mother-infant RSA synchrony during play attenuated associations between maternal PPD symptoms and future child behavior problems and maternal depressive symptoms. 322 low-income, Mexican-origin mothers and their children participated in 5-min resting baseline and free play interaction tasks when children were 24 weeks of age; mothers reported on their PPD symptoms and on child behavior problems and maternal depressive symptoms at 12- and 36-months child age. Results of multilevel structural equation models demonstrated that, though the associations between maternal PPD symptoms and future child behavior problems and maternal depressive symptoms differed depending on levels of RSA synchrony during play and non-interactive tasks, the protective benefits of positive RSA synchrony on 12-month maternal depressive symptoms and 36-month child internalizing problems were specific to its assessment during a playful interaction. Results suggest that the dyadic coordination of physiological capacities during playful interactions is an active mechanism that promotes resilience to emotional distress for mothers and their children.

Understanding allostasis: Early-life self-regulation involves both up- and down-regulation of arousal

Optimal performance lies at intermediate autonomic arousal, but no previous research has examined whether the emergence of endogenous control associates with changes in children's up-regulation from hypo-arousal, as well as down-regulation from hyper-arousal. We used wearables to take day-long recordings from N = 58, 12-month-olds (60% white/58% female); and, in the same infants, we measured self-regulation in the lab with a still-face paradigm. Overall, our findings suggest that infants who showed more self-regulatory behaviors in the lab were more likely to actively change their behaviors in home settings moment-by-moment "on the fly" following changes in autonomic arousal, and that these changes result in up- as well as down-regulation. Implications for the role of atypical self-regulation in later psychopathology are discussed.

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.

Parent-child coregulation as a dynamic system: a commentary on Wass et al. (2024)

In this commentary, I argue that including and operationalizing allostatic processes will become increasingly important in future research on parent-child biobehavioral coregulation. In particular, the conceptualization and modeling of dyadic oscillatory rhythms that align in expected ways with the child's developmental stage and that distinguish typical and atypical development will be useful in future work. Despite the inherent asymmetry characteristic of parent-child relationships, we should not forget to consider the child's effects on the parent within and across time, the additional environmental demands upon parents that shape parent-child coregulation, and variations in parent-child asymmetry by parental risk factors. Studying risk factors that are dyadic in nature, such as child maltreatment, may be particularly informative in gaining a deeper understanding of how parent-child coregulation interfaces with developmental psychopathology. To best model parent-child coregulation as a dynamic system, it will be critical to employ more nonlinear analytic models and better represent the multiple hierarchical domains of coregulation and their interactions, including affect, cognition, behavior, and biology. Finally, in future research, a deeper application of existing dyadic and dynamic theories, as well as the generation of new dyadic developmental theories, will aid us in obtaining a stronger understanding of the developmental function and intervention implications of parent-child biobehavioral coregulation.