Challenging the Sensitive Window Hypothesis: Timing Effects of Maternal Depressive Symptoms on the Intergenerational Transmission of Maltreatment and Psychopathology in the Next Generation.

OBJECTIVE: The current study explored the role of maternal depressive symptoms in the intergenerational transmission of childhood maltreatment and developmental psychopathology. Based on the sensitive window hypothesis, the effects of earlier versus later maternal depression symptoms on child development were analysed. METHOD: Ninety-nine mother-child dyads, 65% of which had high-risk teenage mothers, participated in a longitudinal study with three assessments in the first 18 months of the child's life (T1-T3) and a 4th reassessment (T4) at the child's preschool age. Using serial mediation analyses, we tested whether the relationship between the mother's own maltreatment history (Childhood Experience of Care and Abuse Questionnaire) and the child's psychopathological outcome at preschool age was mediated in a causal effect chain by maternal depression in the first 2 years of life, by current maternal depression (Beck Depression Inventory-II) and by current maternal child abuse potential (Child Abuse Potential Inventory). The children's emotional problems and externalizing symptoms were assessed at preschool age by parent or teacher Strengths and Difficulties Questionnaire ratings. RESULTS: The results indicated that especially later maternal depression mediated the relationship between maternal childhood maltreatment and negative developmental outcomes in the next generation. The effects of maltreatment type on maternal depression were rather nonspecific. However, mental abuse affected existing risk factors more directly over time compared to physical and sexual abuse. Additionally, the impact of early life maltreatment and maternal depression on child psychopathology varied by rater. The pathway to externalizing symptoms was significant only in teacher ratings and for the pathway to emotional problems only in maternal ratings. CONCLUSIONS: The present findings suggest that early maternal depression followed by ongoing maternal depression plays a mediating role in the intergenerational cycle of maltreatment. Therefore, in the future, interventions should be offered at an early stage, but also extend well beyond the first 2 years of a child's life, addressing maternal depression and trauma.

Longitudinal Associations Between Parenting and Child Behaviour Problems and the Moderating Effect of Child Callous Unemotional Traits in Foster and Biological Families.

The goals of the current study were to examine (i) differences in parenting between foster and biological parents, (ii) the longitudinal associations with children's internalising and externalising problems and iii) the potential moderation of these by children's callous-unemotional traits (CU traits). Data from 86 foster children (M = 4.44 years, male = 48%) and 148 biological children (M = 3.69 years, male = 49%) with their families were analysed in a longitudinal study with three measurement times. Parenting behaviour did not significantly differ between the foster and biological family groups. Significant longitudinal cross-lagged effects were found for parental warmth and support and children's externalising problems. CU traits moderated the relationship between warmth and support and externalising problems of children. Findings suggest that parenting behaviours and child psychopathology do influence each other over time reciprocally and to a similar extent in both groups. However, there was also evidence for greater temporal stability of psychopathological symptoms and reduced responsivity to parental warmth in children with higher CU traits.

Multimodal hyperscanning reveals that synchrony of body and mind are distinct in mother-child dyads.

Hyperscanning studies have begun to unravel the brain mechanisms underlying social interaction, indicating a functional role for interpersonal neural synchronization (INS), yet the mechanisms that drive INS are poorly understood. The current study, thus, addresses whether INS is functionally-distinct from synchrony in other systems - specifically the autonomic nervous system and motor behavior. To test this, we used concurrent functional near-infrared spectroscopy - electrocardiography recordings, while N = 34 mother-child and stranger-child dyads engaged in cooperative and competitive tasks. Only in the neural domain was a higher synchrony for mother-child compared to stranger-child dyads observed. Further, autonomic nervous system and neural synchrony were positively related during competition but not during cooperation. These results suggest that synchrony in different behavioral and biological systems may reflect distinct processes. Furthermore, they show that increased mother-child INS is unlikely to be explained solely by shared arousal and behavioral similarities, supporting recent theories that postulate that INS is higher in close relationships.

Interacting brains revisited: A cross-brain network neuroscience perspective.

Elucidating the neural basis of social behavior is a long-standing challenge in neuroscience. Such endeavors are driven by attempts to extend the isolated perspective on the human brain by considering interacting persons' brain activities, but a theoretical and computational framework for this purpose is still in its infancy. Here, we posit a comprehensive framework based on bipartite graphs for interbrain networks and address whether they provide meaningful insights into the neural underpinnings of social interactions. First, we show that the nodal density of such graphs exhibits nonrandom properties. While the current hyperscanning analyses mostly rely on global metrics, we encode the regions' roles via matrix decomposition to obtain an interpretable network representation yielding both global and local insights. With Bayesian modeling, we reveal how synchrony patterns seeded in specific brain regions contribute to global effects. Beyond inferential inquiries, we demonstrate that graph representations can be used to predict individual social characteristics, outperforming functional connectivity estimators for this purpose. In the future, this may provide a means of characterizing individual variations in social behavior or identifying biomarkers for social interaction and disorders.

Caregiving quality modulates neuroendocrine and immunological markers in young children in foster care who have experienced early adversity.

BACKGROUND: Early adversity is believed to alter the body's stress-response systems, putting children at increased risk for somatic and mental health problems. However, it remains unclear whether such alterations normalize under improved caregiving experiences. Thus, the goal of the present study was to investigate (a) whether children in foster care show endocrine and immunological alterations relative to children living with their biological families, (b) whether these alterations change over time spent with the foster family, and (c) whether the alterations are modulated by current caregiving experiences. METHODS: A total of 94 children in foster care and 157 biological children, aged two to seven years, took part in a longitudinal study with three assessments conducted over a 12-month study period. At the initial assessment, children lived for an average of 18 months with their current foster families. Children's cortisol, dehydroepiandrosterone (DHEA) and progesterone concentrations and cortisol/DHEA ratios were measured in scalp hair and children's secretory immunoglobulin A (sIgA) levels in saliva. Caregiving quality was assessed based on caregiver-reports and observational measures of caregiver-child interactions. RESULTS: Children in foster care had lower cortisol/DHEA ratios and higher progesterone concentrations than biological children, while no group differences were found for cortisol, DHEA or sIgA. Time spent with the current foster family did not significantly influence the child's endocrine or immunological markers. Importantly, caregiving quality modulated cortisol/DHEA ratios and sIgA concentrations: children in foster care of lower caregiving quality had lower cortisol/DHEA ratios than children in foster care of higher caregiving quality and showed decreasing, rather than increasing, sIgA concentrations across the study period. CONCLUSIONS: Our results indicate that caregiving quality in the foster family may have an important modulating effect on selected indicators of the child's stress response and could thereby mitigate the possible consequences of early childhood adversity.

Brain-to-brain synchrony in parent-child dyads and the relationship with emotion regulation revealed by fNIRS-based hyperscanning.

Parent-child synchrony, the coupling of behavioral and biological signals during social contact, may fine-tune the child's brain circuitries associated with emotional bond formation and the child's development of emotion regulation. Here, we examined the neurobiological underpinnings of these processes by measuring parent's and child's prefrontal neural activity concurrently with functional near-infrared spectroscopy hyperscanning. Each child played both a cooperative and a competitive game with the parent, mostly the mother, as well as an adult stranger. During cooperation, parent's and child's brain activities synchronized in the dorsolateral prefrontal and frontopolar cortex (FPC), which was predictive for their cooperative performance in subsequent trials. No significant brain-to-brain synchrony was observed in the conditions parent-child competition, stranger-child cooperation and stranger-child competition. Furthermore, parent-child compared to stranger-child brain-to-brain synchrony during cooperation in the FPC mediated the association between the parent's and the child's emotion regulation, as assessed by questionnaires. Thus, we conclude that brain-to-brain synchrony may represent an underlying neural mechanism of the emotional connection between parent and child, which is linked to the child's development of adaptive emotion regulation. Future studies may uncover whether brain-to-brain synchrony can serve as a neurobiological marker of the dyad's socio-emotional interaction, which is sensitive to risk conditions, and can be modified by interventions.

Home-Based EEG Hyperscanning for Infant-Caregiver Social Interactions.

Prior hyperscanning studies that record the brain activities of caregivers and children concurrently have primarily been conducted within the confines of the laboratory, thus limiting the generalizability of results to real-life settings. Here, a comprehensive protocol for capturing synchronized electroencephalography (EEG), electrocardiography (ECG), and behavioral recordings from infant-caregiver dyads during various interactive tasks at home is proposed. This protocol demonstrates how to synchronize the different data streams and report EEG data retention rates and quality checks. Additionally, critical issues and possible solutions with respect to the experimental setup, tasks, and data collection in home settings are discussed. The protocol is not limited to infant-caregiver dyads but can be applied to various dyadic constellations. Overall, we demonstrate the flexibility of EEG hyperscanning setups, which allow experiments to be conducted outside of the laboratory to capture participants' brain activities in more ecologically valid environmental settings. Yet, movement and other types of artifacts still constrain the experimental tasks that can be performed in the home setting.

Interpersonal neural synchrony and mental disorders: unlocking potential pathways for clinical interventions.

Introduction: Interpersonal synchronization involves the alignment of behavioral, affective, physiological, and brain states during social interactions. It facilitates empathy, emotion regulation, and prosocial commitment. Mental disorders characterized by social interaction dysfunction, such as Autism Spectrum Disorder (ASD), Reactive Attachment Disorder (RAD), and Social Anxiety Disorder (SAD), often exhibit atypical synchronization with others across multiple levels. With the introduction of the "second-person" neuroscience perspective, our understanding of interpersonal neural synchronization (INS) has improved, however, so far, it has hardly impacted the development of novel therapeutic interventions. Methods: To evaluate the potential of INS-based treatments for mental disorders, we performed two systematic literature searches identifying studies that directly target INS through neurofeedback (12 publications; 9 independent studies) or brain stimulation techniques (7 studies), following PRISMA guidelines. In addition, we narratively review indirect INS manipulations through behavioral, biofeedback, or hormonal interventions. We discuss the potential of such treatments for ASD, RAD, and SAD and using a systematic database search assess the acceptability of neurofeedback (4 studies) and neurostimulation (4 studies) in patients with social dysfunction. Results: Although behavioral approaches, such as engaging in eye contact or cooperative actions, have been shown to be associated with increased INS, little is known about potential long-term consequences of such interventions. Few proof-of-concept studies have utilized brain stimulation techniques, like transcranial direct current stimulation or INS-based neurofeedback, showing feasibility and preliminary evidence that such interventions can boost behavioral synchrony and social connectedness. Yet, optimal brain stimulation protocols and neurofeedback parameters are still undefined. For ASD, RAD, or SAD, so far no randomized controlled trial has proven the efficacy of direct INS-based intervention techniques, although in general brain stimulation and neurofeedback methods seem to be well accepted in these patient groups. Discussion: Significant work remains to translate INS-based manipulations into effective treatments for social interaction disorders. Future research should focus on mechanistic insights into INS, technological advancements, and rigorous design standards. Furthermore, it will be key to compare interventions directly targeting INS to those targeting other modalities of synchrony as well as to define optimal target dyads and target synchrony states in clinical interventions.

Concurrent and lagged physiological synchrony during mother-child interaction and their relationship to positive affect in 8- to 10-year-old children.

Mother-child interaction has been characterized by a fine-tuning of behavior and physiological activity. Yet, little is known about the dynamics of mother-child physiological synchrony during early school age and their associations to positive affect. To investigate these processes, 42 mother-child dyads, with children aged 8 to 10 years, played an interactive game while their interbeat intervals (IBI) and respiratory sinus arrhythmia (RSA) were measured simultaneously. IBI/RSA synchrony was calculated using cross-correlations of the IBI/RSA second-by-second time series for lags - 3 to + 3 seconds. Mother's and child's individual and shared positive affect were microcoded. During the interactive tasks, IBI and RSA synchrony significantly increased compared to control conditions. RSA and affect synchrony were significantly stronger for negative compared to positive lags indicating a stronger child leads/mother follows covariation. Further, dyad's IBI and RSA synchrony were significantly associated to mother's and child's individual positive affect. Our data suggest that in low-risk community samples, mothers may respond to their children's positive affect by matching their own affect and physiology. Investigating these temporally precise, concurrent and lagged synchrony processes may open up new avenues for understanding the ways in which parent-child interactions contribute to child developmental outcomes.

Revealing the neurobiology underlying interpersonal neural synchronization with multimodal data fusion.

Humans synchronize with one another to foster successful interactions. Here, we use a multimodal data fusion approach with the aim of elucidating the neurobiological mechanisms by which interpersonal neural synchronization (INS) occurs. Our meta-analysis of 22 functional magnetic resonance imaging and 69 near-infrared spectroscopy hyperscanning experiments (740 and 3721 subjects) revealed robust brain regional correlates of INS in the right temporoparietal junction and left ventral prefrontal cortex. Integrating this meta-analytic information with public databases, biobehavioral and brain-functional association analyses suggested that INS involves sensory-integrative hubs with functional connections to mentalizing and attention networks. On the molecular and genetic levels, we found INS to be associated with GABAergic neurotransmission and layer IV/V neuronal circuits, protracted developmental gene expression patterns, and disorders of neurodevelopment. Although limited by the indirect nature of phenotypic-molecular association analyses, our findings generate new testable hypotheses on the neurobiological basis of INS.

Taking Care Triple P for Foster Parents With Young Children in Foster Care: Results of a 1-Year Randomized Trial.

Young children with a history of maltreatment or neglect in foster families often confront their caregivers with particularly challenging behaviors. This may lead to more parenting stress, an increased risk for the child in foster care to experience further maltreatment, and placement disruptions. We conducted a randomized controlled trial to investigate the efficacy of a parent group training tailored to the special needs of foster families. We hypothesized significant short- and long-term improvements regarding foster parents' parenting competencies, child mental health problems, and related outcomes. Eighty-one families with 87 children in foster care aged 2 to 7 years participated in the trial. For the intervention study, 44 randomly selected families (54%) were offered to participate in the parent group training. Intervention and control group families were reassessed three times over a period of 1 year. Contrary to our expectations, we found no advantages of the intervention group compared with the usual care control group on any outcome measure. Instead, we found some significant changes in both groups across time. Placement into foster care is associated with some favorable outcomes for children in foster care. Additional support for foster families beyond the services delivered in the youth welfare system to foster parents was not associated with more favorable outcomes. The present intervention is likely associated with a low risk of harm but also with a high likelihood of a lack of significant benefits for foster parents and their young children going beyond feeling satisfied about the delivered services. Participating foster families showed favorable baseline results on parenting measures which may have impeded intervention effects to unfold on these proximal variables.

Brain and motor synchrony in children and adolescents with ASD-a fNIRS hyperscanning study.

Brain-to-brain synchrony has been proposed as an important mechanism underlying social interaction. While first findings indicate that it may be modulated in children with autism spectrum disorder (ASD), no study to date has investigated the influence of different interaction partners and task characteristics. Using functional near-infrared spectroscopy hyperscanning, we assessed brain-to-brain synchrony in 41 male typically developing (TD) children (8-18 years; control sample), as well as 18 children with ASD and age-matched TD children (matched sample), while performing cooperative and competitive tasks with their parents and an adult stranger. Dyads were instructed either to respond jointly in response to a target (cooperation) or to respond faster than the other player (competition). Wavelet coherence was calculated for oxy- and deoxyhemoglobin brain signals. In the control sample, a widespread enhanced coherence was observed for parent-child competition, and a more localized coherence for parent-child cooperation in the frontopolar cortex. While behaviorally, children with ASD showed a lower motor synchrony than children in the TD group, no significant group differences were observed on the neural level. In order to identify biomarkers for typical and atypical social interactions in the long run, more research is needed to investigate the neurobiological underpinnings of reduced synchrony in ASD.

Auditory and Visual Response Inhibition in Children with Bilateral Hearing Aids and Children with ADHD.

Children fitted with hearing aids (HAs) and children with attention deficit/hyperactivity disorder (ADHD) often have marked difficulties concentrating in noisy environments. However, little is known about the underlying neural mechanism of auditory and visual attention deficits in a direct comparison of both groups. The current functional near-infrared spectroscopy (fNIRS) study was the first to investigate the behavioral performance and neural activation during an auditory and a visual go/nogo paradigm in children fitted with bilateral HAs, children with ADHD and typically developing children (TDC). All children reacted faster, but less accurately, to visual than auditory stimuli, indicating a sensory-specific response inhibition efficiency. Independent of modality, children with ADHD and children with HAs reacted faster and tended to show more false alarms than TDC. On a neural level, however, children with ADHD showed supra-modal neural alterations, particularly in frontal regions. On the contrary, children with HAs exhibited modality-dependent alterations in the right temporopolar cortex. Higher activation was observed in the auditory than in the visual condition. Thus, while children with ADHD and children with HAs showed similar behavioral alterations, different neural mechanisms might underlie these behavioral changes. Future studies are warranted to confirm the current findings with larger samples. To this end, fNIRS provided a promising tool to differentiate the neural mechanisms underlying response inhibition deficits between groups and modalities.

fNIRS Assessment of Speech Comprehension in Children with Normal Hearing and Children with Hearing Aids in Virtual Acoustic Environments: Pilot Data and Practical Recommendations.

The integration of virtual acoustic environments (VAEs) with functional near-infrared spectroscopy (fNIRS) offers novel avenues to investigate behavioral and neural processes of speech-in-noise (SIN) comprehension in complex auditory scenes. Particularly in children with hearing aids (HAs), the combined application might offer new insights into the neural mechanism of SIN perception in simulated real-life acoustic scenarios. Here, we present first pilot data from six children with normal hearing (NH) and three children with bilateral HAs to explore the potential applicability of this novel approach. Children with NH received a speech recognition benefit from low room reverberation and target-distractors' spatial separation, particularly when the pitch of the target and the distractors was similar. On the neural level, the left inferior frontal gyrus appeared to support SIN comprehension during effortful listening. Children with HAs showed decreased SIN perception across conditions. The VAE-fNIRS approach is critically compared to traditional SIN assessments. Although the current study shows that feasibility still needs to be improved, the combined application potentially offers a promising tool to investigate novel research questions in simulated real-life listening. Future modified VAE-fNIRS applications are warranted to replicate the current findings and to validate its application in research and clinical settings.

Conducting Hyperscanning Experiments with Functional Near-Infrared Spectroscopy.

Concurrent brain recordings of two or more interacting persons, an approach termed hyperscanning, are gaining increasing importance for our understanding of the neurobiological underpinnings of social interactions, and possibly interpersonal relationships. Functional near-infrared spectroscopy (fNIRS) is well suited for conducting hyperscanning experiments because it measures local hemodynamic effects with a high sampling rate and, importantly, it can be applied in natural settings, not requiring strict motion restrictions. In this article, we present a protocol for conducting fNIRS hyperscanning experiments with parent-child dyads and for analyzing brain-to-brain synchrony. Furthermore, we discuss critical issues and future directions, regarding the experimental design, spatial registration of the fNIRS channels, physiological influences and data analysis methods. The described protocol is not specific to parent-child dyads, but can be applied to a variety of different dyadic constellations, such as adult strangers, romantic partners or siblings. To conclude, fNIRS hyperscanning has the potential to yield new insights into the dynamics of the ongoing social interaction, which possibly go beyond what can be studied by examining the activities of individual brains.

Children's mental health problems and their relation to parental stress in foster mothers and fathers.

BACKGROUND: This study focuses on children living in foster families with a history of maltreatment or neglect. These children often show adverse mental health outcomes reflected in increased externalizing and internalizing problems. It is expected that these adverse outcomes are associated with increased parental stress levels experienced by foster mothers as well as foster fathers. METHODS: The study sample included 79 children living in foster families and 140 children living in biological families as comparison group. The age of the children ranged from 2 to 7 years. Mental health problems were assessed with the Child Behavior Checklist, while parenting stress was measured with a parenting stress questionnaire including subscales on the amount of experienced stress and the amount of perceived support. The Child Behavior Checklist assessments were based mainly on maternal reports, while the parental stress assessments were based on maternal as well as paternal reports. RESULTS: As expected the results showed increased externalizing and internalizing scores for the foster children accompanied by increased parental stress experiences in the foster family sample (however only in the maternal, but not in the paternal stress reports). The stress differences between the foster and biological family groups disappeared, when the children's mental health problem scores were included as covariates. Moreover, especially the externalizing scores were strong predictors of parental stress in both, the groups of foster and biological parents. The amount of perceived social support was associated with reduced parental stress, but only in the group of biological fathers. CONCLUSION: The emergence of parental stress in biological as well as foster parents is closely related to child characteristics (mainly externalizing child problems). Possible implications for the reduction of parental stress are discussed as a consequence of the present results.