Specifying the neurobiological basis of human attachment: brain, hormones, and behavior in synchronous and intrusive mothers

The Value of Mechanistic Experiments to Target the Shared Neural Circuitry of Parenting and Addiction: The Potential for Video Feedback Interventions

Certain neural processes that underlie addiction are also central to parenting, notably stress and reward. Parenting interventions that incorporate the unique context of caregivers with addiction have demonstrated some success: However, real-world implementation of evidence-based interventions can be difficult with this population. Video feedback interventions are an especially promising approach to reach parents who experience barriers to participation, particularly caregivers with addiction. A translational neuroscientific approach to elucidating the mechanisms of change in these interventions will aid the delivery and success of this method and advance theory surrounding parenting in the context of addiction. Along these lines, we provide an example of one video feedback intervention, Filming Interactions to Nurture Development, that will serve as such a mechanistic experiment.

Fathers' Involvement in Early Childcare is Associated with Amygdala Resting-State Connectivity

Becoming a parent requires new skills and frequent task switching during daily childcare. Little is known about the paternal brain during the transition to fatherhood. The present study examined intrinsic neuronal network connectivity in a group of first-time expectant and new fathers (total N = 131) using amygdala seed-based resting-state functional connectivity analysis. Furthermore, we examined the association between paternal involvement (i.e. hours spent in childcare and real-time push notifications on smartphone) and connectivity within the parental brain network in new fathers. There were no significant differences in functional connectivity between expectant and new fathers. However, results show that in new fathers, time spent in childcare was positively related to amygdala connectivity with the supramarginal gyrus, postcentral gyrus and the superior parietal lobule—all regions within the cognition/mentalizing network that have been associated with empathy and social cognition. Our results suggest that fathers’ time investment in childcare is related to connectivity networks in the parental brain.

Understanding identification-based trust in the light of affiliative bonding: Meta-analytic neuroimaging evidence

Trust is vital for establishing social relationships and is a crucial precursor for affiliative bonds. Investigations explored the neuropsychological bases of trust separately (e.g., measured by the trust game) and affiliative bonding (e.g., measured by parental care, pair-bonding, or friendship). However, direct empirical support for the shared neural mechanisms between trust and affiliative bonding is missing. Here, we conducted a coordinate-based meta-analysis on functional magnetic resonance imaging studies on interpersonal trust and affiliative bonding using the activation likelihood estimation method. Our results demonstrated that decisions to trust strangers in repeated interactions (i.e., identification-based trust) engaged the ventral striatum (vSTR, part of the mesolimbic dopaminergic pathway), likely signaling the reward anticipation. Further, both feedbacks in repeated interactions and affiliative bonding engaged the dorsal striatum (dSTR, part of the nigrostriatal dopaminergic pathway), likely encoding learning dynamics. Our findings suggest that identification-based trust can be understood in the light of affiliative bonding, involving the mesocorticolimbic "reward" pathway (vSTR) and nigrostriatal "habit formation" pathway (dSTR) in building and sustaining social relationships.

Intranasal oxytocin administration but not peripheral oxytocin regulates behaviors of attachment insecurity: A meta-analysis

In light of the roles of oxytocin (OT) in social bonding and interpersonal relationship, studies have examined the roles of OT in human attachment, but by and large previous findings are inconsistent. Here, we conducted - meta-analyses to estimate the associations between peripheral OT level (e.g., blood and salivary OT) and attachment (i.e., attachment dimensions and behaviors of attachment insecurity) and examine the effects of intranasal OT administration on behaviors of attachment insecurity. The analyses indicated that: (1) Peripheral OT level was not significantly associated with attachment dimensions (e.g., attachment anxiety and attachment avoidance) and behaviors of attachment insecurity; (2) intranasal OT administration significantly reduced behaviors of attachment insecurity of neutral contexts, particularly behaviors of attachment avoidance. The findings suggest that intranasal OT administration is an available approach for reducing behaviors of attachment insecurity of interpersonal situations with ambiguous social cues, which implicates suggestions for therapeutic treatments of attachment-related dysfunctions.

What Is Social about Autism? The Role of Allostasis-Driven Learning

Scientific research on neuro-cognitive mechanisms of autism often focuses on circuits that support social functioning. However, autism is a heterogeneous developmental variation in multiple domains, including social communication, but also language, cognition, and sensory-motor control. This suggests that the underlying mechanisms of autism share a domain-general foundation that impacts all of these processes. In this Perspective Review, we propose that autism is not a social deficit that results from an atypical "social brain". Instead, typical social development relies on learning. In social animals, infants depend on their caregivers for survival, which makes social information vitally salient. The infant must learn to socially interact in order to survive and develop, and the most prominent learning in early life is crafted by social interactions. Therefore, the most prominent outcome of a learning variation is atypical social development. To support the hypothesis that autism results from a variation in learning, we first review evidence from neuroscience and developmental science, demonstrating that typical social development depends on two domain-general processes that determine learning: (a) motivation, guided by allostatic regulation of the internal milieu; and (b) multi-modal associations, determined by the statistical regularities of the external milieu. These two processes are basic ingredients of typical development because they determine allostasis-driven learning of the social environment. We then review evidence showing that allostasis and learning are affected among individuals with autism, both neurally and behaviorally. We conclude by proposing a novel domain-general framework that emphasizes allostasis-driven learning as a key process underlying autism. Guided by allostasis, humans learn to become social, therefore, the atypical social profile seen in autism can reflect a domain-general variation in allostasis-driven learning. This domain-general view raises novel research questions in both basic and clinical research and points to targets for clinical intervention that can lower the age of diagnosis and improve the well-being of individuals with autism.

The brain oxytocin and corticotropin-releasing factor systems in grieving mothers: What we know and what we need to learn

The bond between a mother and her child is the strongest bond in nature. Consequently, the loss of a child is one of the most stressful and traumatic life events that causes Prolonged Grief Disorder in up to 94 % of bereaved parents. While both parents are affected, mothers are of higher risk to develop mental health complications; yet, very little research has been done to understand the impact of the loss of a child, stillbirth and pregnancy loss on key neurobiological systems. The emotional impact of losing a child, e.g., Prolonged Grief Disorder, is likely accompanied by dysregulations in neural systems important for mental health. Among those are the neuropeptides contributing to attachment and stress processing. In this review, we present evidence for the involvement of the brain oxytocin (OXT) and corticotropin-releasing factor (CRF) systems, which both play a role in maternal behavior and the stress response, in the neurobiology of grief in mothers from a behavioral and molecular point of view. We will draw conclusions from reviewing relevant animal and human studies. However, the paucity of research on the tragic end to an integral bond in a female's life calls for the need and responsibility to conduct further studies on mothers experiencing the loss of a child both in the clinic and in appropriate animal models.

Social touch deprivation during COVID-19: effects on psychological wellbeing and craving interpersonal touch

Social touch has positive effects on social affiliation and stress alleviation. However, its ubiquitous presence in human life does not allow the study of social touch deprivation 'in the wild'. Nevertheless, COVID-19-related restrictions such as social distancing allowed the systematic study of the degree to which social distancing affects tactile experiences and mental health. In this study, 1746 participants completed an online survey to examine intimate, friendly and professional touch experiences during COVID-19-related restrictions, their impact on mental health and the extent to which touch deprivation results in craving touch. We found that intimate touch deprivation during COVID-19-related restrictions is associated with higher anxiety and greater loneliness even though this type of touch is still the most experienced during the pandemic. Moreover, intimate touch is reported as the type of touch most craved during this period, thus being more prominent as the days practising social distancing increase. However, our results also show that the degree to which individuals crave touch during this period depends on individual differences in attachment style: the more anxiously attached, the more touch is craved; with the reverse pattern for avoidantly attached. These findings point to the important role of interpersonal and particularly intimate touch in times of distress and uncertainty.

The neuroscience of social feelings: mechanisms of adaptive social functioning

Social feelings have conceptual and empirical connections with affect and emotion. In this review, we discuss how they relate to cognition, emotion, behavior and well-being. We examine the functional neuroanatomy and neurobiology of social feelings and their role in adaptive social functioning. Existing neuroscience literature is reviewed to identify concepts, methods and challenges that might be addressed by social feelings research. Specific topic areas highlight the influence and modulation of social feelings on interpersonal affiliation, parent-child attachments, moral sentiments, interpersonal stressors, and emotional communication. Brain regions involved in social feelings were confirmed by meta-analysis using the Neurosynth platform for large-scale, automated synthesis of functional magnetic resonance imaging data. Words that relate specifically to social feelings were identfied as potential research variables. Topical inquiries into social media behaviors, loneliness, trauma, and social sensitivity, especially with recent physical distancing for guarding public and personal health, underscored the increasing importance of social feelings for affective and second person neuroscience research with implications for brain development, physical and mental health, and lifelong adaptive functioning.

Interpersonal Synchrony in the Context of Caregiver-Child Interactions: A Document Co-citation Analysis

Social interactions accompany individuals throughout their whole lives. When examining the underlying mechanisms of social processes, dynamics of synchrony, coordination or attunement emerge between individuals at multiple levels. To identify the impactful publications that studied such mechanisms and establishing the trends that dynamically originated the available literature, the current study adopted a scientometric approach. A sample of 543 documents dated from 1971 to 2021 was derived from Scopus. Subsequently, a document co-citation analysis was conducted on 29,183 cited references to examine the patterns of co-citation among the documents. The resulting network consisted of 1,759 documents connected to each other by 5,011 links. Within the network, five major clusters were identified. The analysis of the content of the three major clusters-namely, "Behavioral synchrony," "Towards bio-behavioral synchrony," and "Neural attunement"-suggests an interest in studying attunement in social interactions at multiple levels of analysis, from behavioral to neural, by passing through the level of physiological coordination. Furthermore, although initial studies on synchrony focused mostly on parent-child interactions, new hyperscanning paradigms are allowing researchers to explore the role of biobehavioral synchrony in all social processes in a real-time and ecological fashion. Future potential pathways of research were also discussed.

Reported maternal childhood maltreatment experiences, amygdala activation and functional connectivity to infant cry

Maternal childhood maltreatment experiences (CMEs) may influence responses to infants and affect child outcomes. We examined associations between CME and mothers' neural responses and functional connectivity to infant distress. We hypothesized that mothers with greater CME would exhibit higher amygdala reactivity and amygdala-supplementary motor area (SMA) functional connectivity to own infant's cries. Postpartum mothers (N = 57) assessed for CME completed an functional magnetic resonance imaging task with cry and white-noise stimuli. Amygdala region-of-interest and psychophysiological interaction analyses were performed. Our models tested associations of CME with activation and connectivity during task conditions (own/other and cry/noise). Exploratory analyses with parenting behaviors were performed. Mothers with higher CME exhibited higher amygdala activation to own baby's cries vs other stimuli (F1,392 = 6.9, P < 0.01, N = 57) and higher differential connectivity to cry vs noise between amygdala and SMA (F1,165 = 22.3, P < 0.001). Exploratory analyses revealed positive associations between both amygdala activation and connectivity and maternal non-intrusiveness (Ps < 0.05). Increased amygdala activation to own infant's cry and higher amygdala-SMA functional connectivity suggest motor responses to baby's distress. These findings were associated with less intrusive maternal behaviors. Follow-up studies might replicate these findings, add more granular parenting assessments and explore how cue processing leads to a motivated maternal approach in clinical populations.

Increased resting-state activity in the cerebellum with mothers having less adaptive sensory processing and trait anxiety

Child‐rearing mothers with high levels of trait anxiety have a tendency for less adaptive sensory processing, which causes parenting stress. However, the neural mechanisms underlying this sensory processing and trait anxiety remain unclear. We aimed to determine the whole‐brain spontaneous neural activity and sensory processing characteristics in mothers with varying parenting stress levels. Using resting‐state functional magnetic resonance imaging, we assessed mothers caring for more than one preschool aged (2–5 years) child and presenting with varying levels of sensory processing, trait anxiety, and parenting stress. Spontaneous neural activities in select brain regions were evaluated by whole‐brain correlation analyses based on the fractional amplitude of low‐frequency fluctuations (fALFF). We found significant positive correlations between levels of sensory processing with trait anxiety and parenting stress. Mothers having less adaptive sensory processing had significantly increased resting‐state network activities in the left lobule VI of the cerebellum. Increased fALFF values in the left lobule VI confirmed the mediation effect on the relationship between trait anxiety and sensory processing. A tendency for less adaptive sensory processing involving increased brain activity in lobule VI could be an indicator of maternal trait anxiety and the risk of parenting stress.

The Application of Connectome-Based Predictive Modeling to the Maternal Brain: Implications for Mother-Infant Bonding

Maternal bonding early postpartum lays an important foundation for child development. Changing brain structure and function during pregnancy and postpartum may underscore maternal bonding. We employed connectome-based predictive modeling (CPM) to measure brain functional connectivity and predict self-reported maternal bonding in mothers at 2 and 8 months postpartum. At 2 months, CPM predicted maternal anxiety in the bonding relationship: Greater integration between cerebellar and motor-sensory-auditory networks and between frontoparietal and motor-sensory-auditory networks were associated with more maternal anxiety toward their infant. Furthermore, greater segregation between the cerebellar and frontoparietal, and within the motor-sensory-auditory networks, was associated with more maternal anxiety regarding their infant. We did not observe CPM prediction of maternal bonding impairments or rejection/anger toward the infant. Finally, considering 2 and 8 months of data, changes in network connectivity were associated with changes in maternal anxiety in the bonding relationship. Our results suggest that changing connectivity among maternal brain networks may provide insight into the mother-infant bond, specifically in the context of anxiety and the representation of the infant in the mother's mind. These findings provide an opportunity to mechanistically investigate approaches to enhance the connectivity of these networks to optimize the representational and behavioral quality of the caregiving relationship.

The association of oxytocin with major depressive disorder: role of confounding effects of antidepressants

Major depressive disorder is a genetic susceptible disease, and a psychiatric syndrome with a high rate of incidence and recurrence. Because of its complexity concerning etiology and pathogenesis, the cure rate of first-line antidepressants is low. In recent years, accumulative evidences revealed that oxytocin act as a physiological or pathological participant in a variety of complex neuropsychological activities, including major depressive disorder. Six electronic databases (Web of Science, PubMed, Scopus, Google Scholar, CNKI, and Wanfang) were employed for researching relevant publications. At last, 226 articles were extracted. The current review addresses the correlation of the oxytocin system and major depressive disorder. Besides, we summarize the mechanisms by which the oxytocin system exerts potential antidepressant effects, including regulating neuronal activity, influencing neuroplasticity and regeneration, altering neurotransmitter release, down regulating hypothalamic-pituitary-adrenal axis, anti-inflammatory, antioxidation, and genetic effects. Increasing evidence shows that oxytocin and its receptor gene may play a potential role in major depressive disorder. Future research should focus on the predictive ability of the oxytocin system as a biomarker, as well as its role in targeted prevention and early intervention of major depressive disorder.

Neural correlates of empathy for babies in postpartum women: A longitudinal study

This study investigated the empathic response of postpartum women to babies in pain and the underlying neural mechanism. Postpartum women responded with more empathy and speed to babies over other stimuli compared to controls. Brain scans taken 3 months after birth showed more elevated activation in the Middle cingulate cortex/middle frontal gyrus (MCC/MFG) than the controls regardless of the task condition. When compared to the adult and neutral conditions, the posterior cingulate cortex (PCC) region was consistently more activated when postpartum women saw babies than controls. In addition, higher activation levels in the PCC region for the baby condition significantly correlated with faster and more empathic responses to babies. Considering that PCC is a core region for the theory of mind or mentalizing which requires cognitive reasoning to understand others, these results suggest that PCC might be a pivotal neural locus facilitating cognitive efforts to empathize with babies during the postpartum period. In a follow‐up experiment at 12 months after birth, we were still able to observe higher activity in the MCC/MFG of postpartum women. However, previously observed PCC activation patterns disappeared 12 months after birth, despite the women's response patterns to babies still being maintained. These results suggest that the mentalizing process activated to empathize with babies in the early postpartum period becomes less cognitively demanding over time.

Delivering Clinically on Our Knowledge of Oxytocin and Sensory Stimulation: The Potential of Infant Carrying in Primary Prevention

Oxytocin (OT) is one of the most intensively researched neuropeptides during the three past decades. In benign social contexts, OT exerts a range of desirable socioemotional, stress-reducing, and immunoregulatory effects in mammals and humans and influences mammalian parenting. Consequentially, research in potential pharmacological applications of OT toward human social deficits/disorders and physical illness has increased substantially. Regrettably, the results from the administration of exogenous OT are still relatively inconclusive. Research in rodent maternal developmental programming has demonstrated the susceptibility of offspring endogenous OT systems to maternal somatosensory stimulation, with consequences for behavioral, epigenetic, cognitive, and neurological outcomes. A translation of this animal research into practically feasible human parenting recommendations has yet to happen, despite the significant prevention potential implied by the maternal developmental programming research. Extended physical contact with full-term healthy infants in the months following birth (infant carrying) might constitute the human equivalent of those specific rodent maternal behaviors, found to positively influence emerging OT systems. Findings from both OT and maternal programming research parallel those found for infants exposed to such extended parental physical contact, whether through skin-to-skin contact or infant carrying. Clinical support of parents to engage in extended physical contact represents a feasible intervention to create optimum conditions for the development of infant OT systems, with potential beneficial long-term health effects.

Synchronous caregiving from birth to adulthood tunes humans' social brain

A birth-to-adulthood study tested the effects of maternal–newborn contact and synchronous caregiving on the social processing brain in human adults. For two decades, we followed preterm and full-term neonates, who received or lacked initial maternal bodily contact, repeatedly observing mother–child social synchrony. We measured the brain basis of affect-specific empathy in young adulthood to pinpoint regions sensitive to others’ distinct emotions. Maternal–newborn contact enhanced social synchrony across development, which, in turn, predicted amygdalar and insular sensitivity to emotion-specific empathy. Findings demonstrate the long-term effects of maternal caregiving in humans, similar to their role in other mammals, particularly in tuning core regions implicated in salience detection, simulation, and interoception that sustain empathy and human attachment.

Mammalian young are born with immature brain and rely on the mother’s body and caregiving behavior for maturation of neurobiological systems that sustain adult sociality. While research in animal models indicated the long-term effects of maternal contact and caregiving on the adult brain, little is known about the effects of maternal–newborn contact and parenting behavior on social brain functioning in human adults. We followed human neonates, including premature infants who initially lacked or received maternal–newborn skin-to-skin contact and full-term controls, from birth to adulthood, repeatedly observing mother–child social synchrony at key developmental nodes. We tested the brain basis of affect-specific empathy in young adulthood and utilized multivariate techniques to distinguish brain regions sensitive to others’ distinct emotions from those globally activated by the empathy task. The amygdala, insula, temporal pole (TP), and ventromedial prefrontal cortex (VMPFC) showed high sensitivity to others’ distinct emotions. Provision of maternal–newborn contact enhanced social synchrony across development from infancy and up until adulthood. The experience of synchrony, in turn, predicted the brain’s sensitivity to emotion-specific empathy in the amygdala and insula, core structures of the social brain. Social synchrony linked with greater empathic understanding in adolescence, which was longitudinally associated with higher neural sensitivity to emotion-specific empathy in TP and VMPFC. Findings demonstrate the centrality of synchronous caregiving, by which infants practice the detection and sharing of others’ affective states, for tuning the human social brain, particularly in regions implicated in salience detection, interoception, and mentalization that underpin affect sharing and human attachment.

Mother brain is wired for social moments

Reorganization of the maternal brain upon childbirth triggers the species-typical maternal social behavior. These brief social moments carry profound effects on the infant's brain and likely have a distinct signature in the maternal brain. Utilizing a double-blind, within-subject oxytocin/placebo administration crossover design, mothers' brain was imaged twice using fMRI while observing three naturalistic maternal-infant contexts in the home ecology; 'unavailable', 'unresponsive', and 'social', when mothers engaged in synchronous peek-a-boo play. The social condition elicited greater neural response across the human caregiving network, including amygdala, VTA, hippocampus, insula, ACC, and temporal cortex. Oxytocin impacted neural response primarily to the social condition and attenuated differences between social and non-social stimuli. Greater temporal consistency emerged in the 'social' condition across the two imaging sessions, particularly in insula, amygdala, and TP. Findings describe how mother's brain varies by caregiving experiences and gives salience to moments of social synchrony that support infant development and brain maturation.

Neural signatures of parental empathic responses to imagined suffering of their adolescent child

Empathy is deemed indispensable for sensitive caregiving. Neuroimaging studies have identified canonical empathy networks consisting of regions supporting cognitive and affective aspects of empathy. However, not much is known about how these regions support empathy towards one's own offspring and how this neural activity relates to parental caregiving. We introduce a novel task to assess affective and neural responses to the suffering of one's own adolescent child. While in the scanner, 60 parents (n = 35 mothers, n = 25 fathers) were confronted with unpleasant situations involving their own child, an unfamiliar child, and themselves. Parents were asked to vividly imagine these situations and indicate their levels of distress. Parents reported higher levels of distress when imagining suffering for their own child relative to an unfamiliar child or themselves. Neuroimaging results showed increased activation within the cognitive empathy network (i.e., temporoparietal junction, dorsomedial- and ventromedial prefrontal cortex) when contrasting suffering of one's own child versus an unfamiliar child or the self. The task also engaged regions of the affective empathy network (i.e., anterior insula and anterior mid-cingulate cortex), which was however not modulated by whether suffering was for the self, one's own child, or an unfamiliar child. Parental care did not co-vary with activity in the empathy networks, but parents who were perceived as less caring exhibited increased activity in anterior prefrontal regions when imagining their own child suffering. These results provide new insights into neural processes supporting parental empathy, highlighting the importance of regions in the cognitive empathy network when confronted with the suffering of their own adolescent child, and suggest that additional (i.e., emotion regulation) networks may be relevant for parental caring behavior in daily life.

Affective Neural Mechanisms of a Parenting-Focused Mindfulness Intervention

OBJECTIVES

Behavioral evidence suggests that parenting-focused mindfulness interventions can improve parenting practices and enhance family wellbeing, potentially operating through altered emotional processing in parents. However, the mechanisms through which parent mindfulness interventions achieve their positive benefits have not yet been empirically tested, knowledge which is key to refine and maximize intervention effects. Thus, as part of a randomized controlled trial, the present study examined the affective mechanisms of an 8-week parenting-focused mindfulness intervention, the Parenting Mindfully (PM) intervention, versus a minimal-intervention parent education control.

METHODS

Twenty highly stressed mothers of adolescents completed pre- and post-intervention behavioral and fMRI sessions, in which mothers completed a parent-adolescent conflict interaction, fMRI emotion task, and fMRI resting state scan. Mothers reported on their mindful parenting, and maternal emotional reactivity to the parent-adolescent conflict task was assessed via observed emotion expression, self-reported negative emotion, and salivary cortisol reactivity.

RESULTS

Results indicated that the PM intervention increased brain responsivity in left posterior insula in response to negative affective stimuli, and altered resting state functional connectivity in regions involved in self-reference, behavioral regulation, and social-emotional processing. Changes in mothers' brain function and connectivity were associated with increased mindful parenting and decreased emotional reactivity to the parent-adolescent conflict task.

CONCLUSIONS

Findings suggest that mindfulness-based changes in maternal emotional awareness at the neurobiological level are associated with decreased emotional reactivity in parenting interactions, illuminating potential neurobiological targets for future parent-focused intervention.

How stress can influence brain adaptations to motherhood

Research shows that a woman's brain and body undergo drastic changes to support her transition to parenthood during the perinatal period. The presence of this plasticity suggests that mothers' brains may be changed by their experiences. Exposure to severe stress may disrupt adaptive changes in the maternal brain and further impact the neural circuits of stress regulation and maternal motivation. Emerging literature of human mothers provides evidence that stressful experience, whether from the past or present environment, is associated with altered responses to infant cues in brain circuits that support maternal motivation, emotion regulation, and empathy. Interventions that reduce stress levels in mothers may reverse the negative impact of stress exposure on the maternal brain. Finally, outstanding questions regarding the timing, chronicity, types, and severity of stress exposure, as well as study design to identify the causal impact of stress, and the role of race/ethnicity are discussed.

Exploring the dog-human relationship by combining fMRI, eye-tracking and behavioural measures

Behavioural studies revealed that the dog-human relationship resembles the human mother-child bond, but the underlying mechanisms remain unclear. Here, we report the results of a multi-method approach combining fMRI (N = 17), eye-tracking (N = 15), and behavioural preference tests (N = 24) to explore the engagement of an attachment-like system in dogs seeing human faces. We presented morph videos of the caregiver, a familiar person, and a stranger showing either happy or angry facial expressions. Regardless of emotion, viewing the caregiver activated brain regions associated with emotion and attachment processing in humans. In contrast, the stranger elicited activation mainly in brain regions related to visual and motor processing, and the familiar person relatively weak activations overall. While the majority of happy stimuli led to increased activation of the caudate nucleus associated with reward processing, angry stimuli led to activations in limbic regions. Both the eye-tracking and preference test data supported the superior role of the caregiver's face and were in line with the findings from the fMRI experiment. While preliminary, these findings indicate that cutting across different levels, from brain to behaviour, can provide novel and converging insights into the engagement of the putative attachment system when dogs interact with humans.

Affectionless control: A parenting style associated with obesity and binge eating disorder in adulthood

OBJECTIVE

Obesity is rising globally with a heavy health and economic burden. Early attachment experiences are relevant to the development of obesity. The purpose of this study was to investigate if parental care and attachment style experienced in childhood is associated with obesity, with or without binge eating disorder (BED), in adulthood.

METHOD

Parental style, personality traits, and psychopathology were assessed in 810 clinically referred adults with obesity, of whom 357 with BED and 453 without BED (non-BED), and 463 healthy subjects (HS). Assessments included the Parental Bonding Instrument, Temperament and Character Inventory, Eating Disorder Inventory-2, Symptom Checklist-90 and Beck Depression Inventory-II.

RESULTS

Both BED and non-BED reported lower maternal and paternal care and higher overprotection than HS. BED reported worse levels of parental care than non-BED and HS. 'Affectionless control' parenting style was more frequently reported by both BED and non-BED than HS. No significant differences in parenting style emerged between BED and non-BED.

CONCLUSIONS

Perception of parental 'affectionless control' was associated with obesity in adults, and lower quality of parental care was more frequently reported by participants with BED. Parental style may constitute an important target for early interventions to prevent obesity.

Blocking mu-opioid receptors inhibits social bonding in rituals

Religious rituals are universal human practices that play a seminal role in community bonding. In two experiments, we tested the role of mu-opioids as the active factor fostering social bonding. We used a mu-opioid blocker (naltrexone) in two double-blind studies of rituals from different religious traditions. We found the same effect across both studies, with naltrexone leading to significantly lower social bonding compared with placebo. These studies suggest that mu-opioids play a significant role in experiences of social bonding within ritual contexts.

Concordance in parent and offspring cortico-basal ganglia white matter connectivity varies by parental history of major depressive disorder and early parental care

Social behavior is transmitted cross-generationally through coordinated behavior within attachment bonds. Parental depression and poor parental care are major risks for disruptions of such coordination and are associated with offspring's psychopathology and interpersonal dysfunction. Given the key role of the cortico-basal ganglia (CBG) circuits in social communication, we examined similarities (concordance) of parent-offspring CBG white matter (WM) connections and how parental history of major depressive disorder (MDD) and early parental care moderate these similarities. We imaged 44 parent-offspring dyads and investigated WM connections between basal-ganglia seeds and selected regions in temporal cortex using diffusion tensor imaging (DTI) tractography. We found significant concordance in parent-offspring strength of CBG WM connections, moderated by parental lifetime-MDD and care. The results showed diminished neural concordance among dyads with a depressed parent and that better parental care predicted greater concordance, which also provided a protective buffer against attenuated concordance among dyads with a depressed parent. Our findings provide the first neurobiological evidence of concordance between parents-offspring in WM tracts and that concordance is diminished in families where parents have lifetime-MDD. This disruption may be a risk factor for intergenerational transmission of psychopathology. Findings emphasize the long-term role of early caregiving in shaping the neural concordance among at-risk and affected dyads.

Associations between stress exposure and new mothers' brain responses to infant cry sounds

Exposure to severe stress has been linked to negative postpartum outcomes among new mothers including mood disorders and harsh parenting. Non-human animal studies show that stress exposure disrupts the normative adaptation of the maternal brain, thus identifying a neurobiological mechanism by which stress can lead to negative maternal outcomes. However, little is known about the impact of stress exposure on the maternal brain response to infant cues in human mothers. We examined the association of stress exposure with brain response to infant cries and maternal behaviors, in a socioeconomically diverse (low- and middle-income) sample of first-time mothers (N=53). Exposure to stress across socioeconomic, environmental, and psychosocial domains was associated with reduced brain response to infant cry sounds in several regions, including the right insula/inferior frontal gyrus and superior temporal gyrus. Reduced activation in these regions was further associated with lower maternal sensitivity observed during a mother-infant interaction. The findings demonstrate that higher levels of stress exposure may be associated with reduced brain response to an infant’s cry in regions that are important for emotional and social information processing, and that reduced brain responses may further be associated with increased difficulties in developing positive mother-infant relationships.

Relationship between parenthood and cortical thickness in late adulthood

Pregnancy and the early postpartum period alter the structure of the brain; particularly in regions related to parental care. However, the enduring effects of this period on human brain structure and cognition in late life is unknown. Here we use magnetic resonance imaging to examine differences in cortical thickness related to parenthood in late life, for both sexes. In 235 healthy older women, we find a positive relationship between parity (number of children parented) and memory performance in mothers. Parity was also associated with differences in cortical thickness in women in the parahippocampus, precuneus, cuneus and pericalcarine sulcus. We also compared non-parents to parents of one child, in a sub-sample of older women (N = 45) and men (N = 35). For females, six regions differed in cortical thickness between parents and non-parents; these regions were consistent with those seen earlier in life in previous studies. For males, five regions differed in cortical thickness between parents and non-parents. We are first to reveal parenthood-related brain differences in late-life; our results are consistent with previously identified areas that are altered during pregnancy and the postpartum period. This study provides preliminary evidence to suggest that neural changes associated with early stages of parenthood persist into older age, and for women, may be related to marginally better cognitive outcomes.

Early detection of parenting stress in mothers of preterm infants during their first-year home

Background

Maternal stress following the birth of an infant is well acknowledged. It is particularly so when infants are born prematurely as their mothers cannot fully take on their parenting role until their infant(s) is discharged from neonatal intensive care units (NICUs). In this exploratory study, we examined whether these mothers’ parenting stress would lessen during their first-year reunification with their infant(s) as they settle into motherhood at home.

Methods

Two groups of mothers with infants born between 24- and 33-week gestational age were recruited. A group of 25 mothers were monitored at their infants’ 1-month corrected age (CA) and a second group of 24 mothers were monitored at their infants’ 12-month CA. Subjects completed the long form Parental Stress Index (PSI) ranking how stressful they perceive the individual subscales in the Child and Parent Domains of the self-reported questionnaire (PSI-3; Abidin; PAR Inc). The PSI theorizes that the stress mothers perceive is a resultant of their respective characteristics, interactions with their infant(s), family, and environment. Statistical analyses include descriptive statistics, χ² square analysis, and independent t-test.

Results

There was no significant difference in the levels of perceived stress in the PSI subscales between the two groups of mothers at 1- and 12-month CA. Scores for the majority of respondents fell within the 15th to 80th percentile (% ile) distribution of Abidin’s normative population, with some mothers falling below the 15th % ile.

Discussion/conclusion

The data collected suggest that: 1. the perceived stress experienced by mothers during their first-year reunited with their preterm infants is within the normal range observed in Abidin’s normative population. 2. As the PSI is a self-reported survey, care providers need to be aware that some mothers may downplay their stress responses. 3. With the ability to monitor individual participants, the PSI can be readily offered to mothers at their infants’ first year routine clinical visits to assist in the early identification of parenting issues that may threaten the development of a healthy mother-infant dyad. Early appropriate guidance and social support would help “at-risk” mothers develop more constructive parenting routines.

What is resilience: an affiliative neuroscience approach

Resilience - a key topic in clinical science and practice - still lacks a clear conceptualization that integrates its evolutionary and human-specific features, refrains from exclusive focus on fear physiology, incorporates a developmental approach, and, most importantly, is not based on the negation (i.e., absence of symptoms following trauma). Building on the initial condition of mammals, whose brain matures in the context of the mother's body and caregiving behavior, we argue that systems and processes that participate in tuning the brain to the social ecology and adapting to its hardships mark the construct of resilience. These include the oxytocin system, the affiliative brain, and biobehavioral synchrony, all characterized by great flexibility across phylogenesis and ontogenesis. Three core features of resilience are outlined: plasticity, sociality and meaning. Mechanisms of sociality by which coordinated action supports diversity, endurance and adaptation are described across animal evolution. Humans' biobehavioral synchrony matures from maternal attuned behavior in the postpartum to adult-adult relationships of empathy, perspective-taking and intimacy, and extends from the mother-child relationship to other affiliative bonds throughout life, charting a fundamental trajectory in the development of resilience. Findings from three high-risk cohorts, each tapping a distinct disruption to maternal-infant bonding (prematurity, maternal depression, and early life stress/trauma), and followed from birth to adolescence/young adulthood, demonstrate how components of the neurobiology of affiliation confer resilience and uniquely shape the social brain.

Oxytocin receptor gene and parental bonding modulate prefrontal responses to cries: a NIRS Study

The ability to interpret and regulate emotions relies on experiences of emotional socialization, obtained firstly through the interaction with the parents, and on genetic features that affect how individuals take on social situations. Evidence from the genetic field states that specific allelic variations of the oxytocin receptor gene polymorphisms regulate physiological modulation of human behavior, especially concerning responses to social cues and affiliative behaviors. Starting from this gene-by-environment interaction frame, we assessed 102 young adults for OXTr rs53576 and rs2254298, recalled parental bonding (using the Parental Bonding Instrument), and recorded participants' neural responses to social stressors using Near InfraRed Spectroscopy (NIRS). The results highlight that higher genetic susceptibility (G/G homozygous) to familiar context and positive early life interactions modulate more optimal neural responses to general social cues, in terms of promptness to action. With regards to the dimensions of parental bonding, we found lateralized effects, with greater activation in the right prefrontal cortex for Care subscales, and on the left side of the prefrontal cortex for Overprotection. Results provide evidence to understand the neurological mechanisms behind the negative impact of poor parenting practices on the child.

What a cute baby! Preliminary evidence from a fMRI study for the association between mothers' neural responses to infant faces and activation of the parental care system

Infant facial characteristics, i.e., baby schema, are thought to automatically elicit parenting behavior and affective orientation toward infants. Only a few studies, conducted in non-parents, have directly examined the neural underpinnings of this baby schema effect by manipulating distinctiveness of baby schema in infant faces. This study aims to further our understanding of the intuitive nature of parenting, by studying the baby schema effect in mothers of young children (at least one child aged between 2 and 6 years old). Functional magnetic resonance imaging (fMRI) was used to examine mothers' (N = 23) neural responses to unfamiliar infant faces varying in distinctiveness of baby schema. Also, it was studied how this neural activation to infant faces was associated with maternal nurturance. Results revealed that infant faces elicited widespread activation in bilateral visual cortices, the hippocampus, sensory-motor areas, parietal and frontal cortices, and the insula, which was not modulated by the distinctiveness of baby schema in the infant faces. Furthermore, higher self-reported maternal nurturance was related to increased neural responses to infant faces in the putamen and amygdala, brain regions known to be associated with reward and salience processing. These findings could suggest that in our small sample of mothers some of the core networks involved in reward and salience processing might be less sensitive to variation in distinctiveness of baby schema. Also, unfamiliar infant faces seem to be rewarding only for mothers who report high nurturance. These findings should be considered preliminary, because they need to be replicated in studies with larger samples.

Attention bias to infant faces in pregnant women predicts maternal sensitivity

While research has shown that attention bias to infant faces is linked to parenting, this work is largely cross-sectional and limited to the postpartum period. Because the transition to motherhood from pregnancy to birth constitutes a sensitive period in cortical reorganization linked to the quality of mother-infant interactions, evaluating attention processes in the maternal cortex prior to the experience of mother-infant face-to-face interactions is critical. To assess behavioural attention and neural responses to infant faces in pregnant mothers, behavioral and electrocortical indices were collected using a Go/No Go task, in which infant and adult faces served as distractors. Results showed that heightened processing of infant faces relative to adult faces (behavioral and electrocortical indices) was related to observations of greater maternal sensitivity. These findings show that prenatal maternal attention bias to and the perceived salience of infant faces serves as an individual cognitive hallmark of maternal sensitivity that acts independently of caregiving experience.

Adaptations in reward-related behaviors and mesolimbic dopamine function during motherhood and the postpartum period

Initiation and maintenance of maternal behavior is driven by a complex interaction between the physiology of parturition and offspring stimulation, causing functional changes in maternal brain and behavior. Maternal behaviors are among the most robust and rewarding motivated behaviors. Mesolimbic dopamine (DA) system alterations during pregnancy and the postpartum enable enhanced reward-related responses to offspring stimuli. Here, we review behavioral evidence demonstrating postpartum rodents exhibit a bias towards pups and pup-related stimuli in reward-related tasks. Next, we provide an overview of normative adaptations in the mesolimbic DA system induced by parturition and the postpartum, which likely mediate shifts in offspring valence. We also discuss a causal link between dopaminergic dysfunction and disrupted maternal behaviors, which are recapitulated in postpartum depression (PPD) and relevant rodent models. In sum, mesolimbic DA system activation drives infant-seeking behavior and strengthens the mother-infant bond, potentially representing a therapeutic target for reward-related deficits in PPD.

Becoming a mother entails anatomical changes in the ventral striatum of the human brain that facilitate its responsiveness to offspring cues

In mothers, offspring cues are associated with a powerful reinforcing value that motivates maternal care. Animal studies show that this is mediated by dopamine release into the nucleus accumbens, a core component of the brain's reward system located in the ventral striatum (VStr). The VStr is also known to respond to infant signals in human mothers. However, it is unknown whether pregnancy modifies the anatomy or functionality of this structure, and whether such modifications underlie its strong reactivity to offspring cues. Therefore, we analyzed structural and functional neuroimaging data from a unique pre-conception prospective cohort study involving first-time mothers investigated before and after their pregnancy as well as nulliparous control women scanned at similar time intervals. First, we delineated the anatomy of the VStr in each subject's neuroanatomical space and examined whether there are volumetric changes in this structure across sessions. Then, we tested if these changes could predict the mothers' brain responses to visual stimuli of their infants. We found decreases in the right VStr and a trend for left VStr reductions in the women who were pregnant between sessions compared to the women who were not. Furthermore, VStr volume reductions across pregnancy were associated with infant-related VStr responses in the postpartum period, with stronger volume decreases predicting stronger functional activation to offspring cues. These findings provide the first indications that the transition to motherhood renders anatomical adaptations in the VStr that promote the strong responsiveness of a mother's reward circuit to cues of her infant.

Maternal Neurobiological Processing of Negative Adolescent Stimuli: Relations With Positive Parenting and Relationship Quality

We examined associations between maternal affective neurobiology and positive parenting in a study of 20 mothers of adolescents. Mothers underwent functional magnetic resonance imaging during an emotion image task, rated parent-adolescent relationship quality, and completed an adolescent interaction task in which positive parenting behaviors were observed. Maternal structure was associated with lower responsivity in emotional processing regions in the general negative image contrast and was related to greater dorsolateral prefrontal cortex activation to negative adolescent images. Parent-adolescent relationship quality was associated with lower precuneus activation to negative adolescent images. Findings are among the first to connect functional brain processing with observed parenting behaviors for parents of adolescent children, and underscore the relative importance of affective processing in parenting older children.

Exploring the neural basis for paternal protection: an investigation of the neural response to infants in danger

Perceiving potential threat to an infant and responding to it is crucial for offspring survival and parent–child bonding. Using a combination of functional magnetic resonance imaging and multi-informant reports, this longitudinal study explores the neural basis for paternal responses to threat to infants pre-natally (N = 21) and early post-natally (n = 17). Participants viewed videos showing an infant in danger and matched control videos, while instructed to imagine that the infant was their own or someone else’s. Effects were found for infant-threatening vs neutral situations in the amygdala (region-of-interest analyses) and in clusters spanning cortical and subcortical areas (whole-brain analyses). An interaction effect revealed increased activation for own (vs unknown) infants in threatening (vs neutral) situations in bilateral motor areas, possibly indicating preparation for action. Post-natal activation patterns were similar; however, in part of the superior frontal gyrus the distinction between threat to own and unknown infant faded. Fathers showing more protective behavior in daily life recruited part of the frontal pole more when confronted with threat to their own vs an unknown infant. This exploratory study is the first to describe neural mechanisms involved in paternal protection and provides a basis for future work on fathers’ protective parenting.

Maternal responsivity and oxytocin in opioid-dependent mothers

Although prenatal opioid exposure and postnatal withdrawal (neonatal abstinence syndrome) are associated with infant neurobehavioral deficits, little is known about the impact of continued maternal opioid treatment in the postnatal period on maternal responsivity and relationship to mother's oxytocin release during dyadic interactions in the Still Face paradigm. Mother and infant dyads (N = 14) were recruited and comprised of mothers on opioid replacement throughout pregnancy and postpartum (opioid-exposed group, n = 7) and a demographically controlled, non-exposed group (n = 7). Salivary oxytocin was collected following 10 min of infant separation before and immediately after a 6-min Still Face paradigm. Oxytocin measures correlated strongly with sensitive and prosocial maternal behaviors in response to infant initiation. Opioid-exposed compared to non-exposed mothers had significantly lower pre-test to post-test rise in salivary oxytocin concentration level as well as fewer sensitive behaviors during the reunion condition of the Still Face paradigm. Maternal opioid dependence during early infancy may impair maternal responsivity and sensitivity through suppression of the oxytocin reflex to infant stimulation.

Interactive Psychometrics for Autism With the Human Dynamic Clamp: Interpersonal Synchrony From Sensorimotor to Sociocognitive Domains

The human dynamic clamp (HDC) is a human-machine interface designed on the basis of coordination dynamics for studying realistic social interaction under controlled and reproducible conditions. Here, we propose to probe the validity of the HDC as a psychometric instrument for quantifying social abilities in children with autism spectrum disorder (ASD) and neurotypical development. To study interpersonal synchrony with the HDC, we derived five standardized scores following a gradient from sensorimotor and motor to higher sociocognitive skills in a sample of 155 individuals (113 participants with ASD, 42 typically developing participants; aged 5 to 25 years; IQ > 70). Regression analyses were performed using normative modeling on global scores according to four subconditions (HDC behavior "cooperative/competitive," human task "in-phase/anti-phase," diagnosis, and age at inclusion). Children with ASD had lower scores than controls for motor skills. HDC motor coordination scores were the best candidates for stratification and diagnostic biomarkers according to exploratory analyses of hierarchical clustering and multivariate classification. Independently of phenotype, sociocognitive skills increased with developmental age while being affected by the ongoing task and HDC behavior. Weaker performance in ASD for motor skills suggests the convergent validity of the HDC for evaluating social interaction. Results provided additional evidence of a relationship between sensorimotor and sociocognitive skills. HDC may also be used as a marker of maturation of sociocognitive skills during real-time social interaction. Through its standardized and objective evaluation, the HDC not only represents a valid paradigm for the study of interpersonal synchrony but also offers a promising, clinically relevant psychometric instrument for the evaluation and stratification of sociomotor dysfunctions.

Potential Neural Mediators of Mom Power Parenting Intervention Effects on Maternal Intersubjectivity and Stress Resilience

Stress resilience in parenting depends on the parent's capacity to understand subjective experiences in self and child, namely intersubjectivity, which is intimately related to mimicking other's affective expressions (i. e., mirroring). Stress can worsen parenting by potentiating problems that can impair intersubjectivity, e.g., problems of "over-mentalizing" (misattribution of the child's behaviors) and "under-coupling" (inadequate child-oriented mirroring). Previously we have developed Mom Power (MP) parenting intervention to promote maternal intersubjectivity and reduce parenting stress. This study aimed to elucidate neural mechanisms underlying the effects of MP with a novel Child Face Mirroring Task (CFMT) in functional magnetic-resonance-imaging settings. In CFMT, the participants responded to own and other's child's facial pictures in three task conditions: (1) empathic mirroring (Join), (2) non-mirroring observing (Observe), and (3) voluntary responding (React). In each condition, each child's neutral, ambiguous, distressed, and joyful expressions were repeatedly displayed. We examined the CFMT-related neural responses in a sample of healthy mothers (n = 45) in Study 1, and MP effects on CFMT with a pre-intervention (T1) and post-intervention (T2) design in two groups, MP (n = 19) and Control (n = 17), in Study 2. We found that, from T1 to T2, MP (vs. Control) decreased parenting stress, decreased dorsomedial prefrontal cortex (dmPFC) during own-child-specific voluntary responding (React to Own vs. Other's Child), and increased activity in the frontoparietal cortices, midbrain, nucleus accumbens, and amygdala during own-child-specific empathic mirroring (Join vs. Observe of Own vs. Other's Child). We identified that MP effects on parenting stress were potentially mediated by T1-to-T2 changes in: (1) the left superior-temporal-gyrus differential responses in the contrast of Join vs. Observe of own (vs. other's) child, (2) the dmPFC-PAG (periaqueductal gray) differential functional connectivity in the same contrast, and (3) the left amygdala differential responses in the contrast of Join vs. Observe of own (vs. other's) child's joyful vs. distressed expressions. We discussed these results in support of the notion that MP reduces parenting stress via changing neural activities related to the problems of "over-mentalizing" and "under-coupling." Additionally, we discussed theoretical relationships between parenting stress and intersubjectivity in a novel dyadic active inference framework in a two-agent system to guide future research.

A Role of Oxytocin Receptor Gene Brain Tissue Expression Quantitative Trait Locus rs237895 in the Intergenerational Transmission of the Effects of Maternal Childhood Maltreatment

OBJECTIVE

Women exposed to childhood maltreatment (CM) are more likely to exhibit insensitive parenting, which may have consequences for their offspring's development. Variation in the oxytocin-receptor gene (OXTR) moderates risk of CM-associated long-term sequelae associated with mother-child attachment, although functionality of previously investigated single nucleotide polymorphisms (SNPs) remained elusive. Here, we investigated the role of OXTR rs237895, a brain tissue expression quantitative trait locus (eQTL), as a moderator of the relationship between CM and maternal behavior (MB) and the association between MB and offspring attachment security.

METHOD

Of 110 women with information on rs237895 genotype (T-allele = 64, CC = 46), 107 had information on CM (CTQ) and 99 on standardized observer-based ratings of MB at 6 months postpartum (responsivity and detachment), which were used in principal component analysis to obtain a latent factor representing MB. Offspring (n = 86) attachment was evaluated at 12 months of age. Analyses predicting MB were adjusted for socioeconomic status, age, postpartum depression, and genotype-based ethnicity. Analyses predicting child attachment were adjusted for infant sex, socioeconomic status, and postpartum depression.

RESULTS

rs237895 significantly moderated the relationship between CM and MB (F1;66 = 7.99, p < .01), indicating that CM was associated with maternal insensitivity only in high-OXTR-expressing T-allele carriers but not in low-OXTR-expressing CC homozygotes. Moreover, maternal insensitivity predicted offspring insecure attachment (B = -0.551; p < .05).

CONCLUSION

Women with a high OXTR expressing genotype are more susceptible to CM-related impairments in MB that, in turn, predict attachment security in their children, supporting the role of the OT system in the intergenerational transmission of risk associated with maternal CM.

Oxytocin and early parent-infant interactions: A systematic review

Objectives

Social relationships throughout lifespan are critical for health and wellbeing. Oxytocin, often called the ‘hormone of attachment’ has been suggested as playing an important role in early-life nurturing and resulting social bonding. The objective of this paper is to synthesize the associations between oxytocin levels and interactions between infants and parents that may trigger oxytocin release, and in turn facilitate attachments.

Methods

A comprehensive cross-disciplinary systematic search was completed using electronic databases. The inclusion criteria included studies that focused on mother-infant and father-infant interaction and measured both baseline and post-interaction oxytocin levels.

Results

Seventeen studies were included in the final systematic review. The reviewed studies used mother-infant and/or father-infant play and skin-to-skin contact between maternal-infant and paternal-infant dyads to examine the oxytocin role in early life bonding and parenting processes. Studies showed a positive correlation between parent-infant contact and oxytocin levels in infancy period. Increased maternal oxytocin levels were significantly related to more affectionate contact behaviors in mothers following mother-infant contact, synchrony, and engagement. Meanwhile, increased paternal oxytocin levels were found to be related to more stimulatory contact behaviors in fathers following father-infant contact. Oxytocin levels significantly increased in infants, mothers and fathers during skin-to-skin contact and parents with higher oxytocin levels exhibited more synchrony and responsiveness in their infant interactions.

Conclusion

The review suggests that oxytocin plays an important role in the development of attachment between infants and parents through early contact and interaction. The complexities of oxytocinergic mechanisms are rooted in neurobiological, genetic, and social factors.

Maternal brain resting-state connectivity in the postpartum period

In the postpartum period, the maternal brain experiences both structural and functional plasticity. Although we have a growing understanding of the responses of the human maternal brain to infant stimuli, little is known about the intrinsic connectivity among those regions during the postpartum months. Resting-state functional connectivity (rsFC) provides a measure of the functional architecture of the brain based upon intrinsic functional connectivity (ie, the temporal correlation in blood oxygenation level dependent signal when the brain is not engaged in a specific task). In the present study, we used resting-state functional magnetic resonance imaging to examine how later postpartum months are associated with rsFC and maternal behaviours. We recruited a sample of 47 socioeconomically diverse first-time mothers with singleton pregnancies. Because the amygdala has been shown to play a critical role in maternal behaviours in the postpartum period, this was chosen as the seed for a seed-based correlation analysis. For the left amygdala, later postpartum months were associated with greater connectivity with the anterior cingulate gyrus, left nucleus accumbens, right caudate and left cerebellum (P < 0.05, false discovery rate corrected). Furthermore, in an exploratory analysis, we observed indications that rsFC between the left amygdala and left nucleus accumbens was positively associated with maternal structuring during a mother child-interaction. In addition, later postpartum months were associated with greater connectivity between the right amygdala and the bilateral caudate and right putamen. Overall, we provide evidence of relationships between postpartum months and rsFC in the regions involved in salience detection and regions involved in maternal motivation. Greater connectivity between the amygdala and nucleus accumbens may play a role in positive maternal behaviours.

A tumultuous transition to motherhood: Altered brain and hormonal responses in mothers with postpartum depression

Postpartum depression (PPD) is a common but complex condition that is poorly understood and multifactorial in aetiology. It is a condition that can compromise the mother's care for her infant, which may pose challenges to the formation of the mother-infant bond and the infant's overall development. Past research has looked at abnormalities in the brain circuitry and hormonal profiles of mothers with PPD compared to non-depressed mothers. However, abnormalities in PPD that may specifically affect the mother's care of her infant have not been clearly assessed. Thus, the present review aims to synthesise studies of altered brain and hormonal responses in mothers with PPD in relation to their care of their infant. First, we review maternal brain responses and their relation to PPD symptomatology, focusing on the salience/fear network, reward/attachment network and default mode network. Next, we discuss oxytocin and hypothalamic-pituitary-adrenal axis hormones in the context of maternal behaviour and PPD. Finally, we synthesise these findings and propose how future studies may benefit from the combined study of both neural and hormonal activity to better understand the underlying neurobiology of maternal care in PPD.

Intergenerational transmission of depression: clinical observations and molecular mechanisms

Maternal mental illness can have a devastating effect during the perinatal period, and has a profound impact on the care that the baby receives and on the relationships that the baby forms. This review summarises clinical evidence showing the effects of perinatal depression on offspring physical and behavioural development, and on the transmission of psychopathology between generations. We then evaluate a number of factors which influence this relationship, such as genetic factors, the use of psychotropic medications during pregnancy, the timing within the perinatal period, the sex of the foetus, and exposure to maltreatment in childhood. Finally, we examine recent findings regarding the molecular mechanisms underpinning these clinical observations, and identify relevant epigenetic and biomarker changes in the glucocorticoid, oxytocin, oestrogen and immune systems, as key biological mediators of these clinical findings. By understanding these molecular mechanisms in more detail, we will be able to improve outcomes for both mothers and their offspring for generations.

Chronic trauma impairs the neural basis of empathy in mothers: Relations to parenting and children's empathic abilities

Early life stress carries long-term negative consequences for children's well-being and maturation of the social brain. Here, we utilize a unique cohort to test its effects on mothers' social brain, targeting mothers' neural empathic response in relation to caregiving and child empathic abilities. Mother-child dyads living in a zone of repeated war-related trauma were followed from early childhood and mother-child behavioral synchrony was repeatedly observed. At pre-adolescence(11-13 years) children's empathic abilities were assessed and mothers(N = 88, N = 44 war-exposed) underwent magnetoencephalography(MEG) while exposed to vicarious pain. All mothers showed alpha suppression in sensorimotor regions, indicating automatic response to others' pain. However, trauma-exposed mothers did not exhibit gamma oscillations in viceromotor cortex, a neural marker of mature empathy which utilizes interoceptive mechanisms for higher-order understanding and does not emerge before adulthood. Mother-child synchrony across the first decade predicted mothers' viceromotor gamma, and both synchrony and maternal viceromotor gamma mediated the relations between war-exposure and child empathic abilities, possibly charting a cross-generational pathway from mothers' mature neural empathy to children's empathic capacities. Our findings are first to probe the maternal social brain in adolescence in relation to parenting and underscore the need for targeted interventions to mothers raising children in contexts of chronic stress.

Exposure to early and persistent maternal depression impairs the neural basis of attachment in preadolescence

Maternal depression increases child vulnerability to psychopathology, loneliness, and social maladjustment; yet, its long-term effects on the social brain are unknown. In this prospective longitudinal study we examined the impact of early and persistent maternal depression on the neural basis of attachment in preadolescence. A community cohort was followed in two groups; children exposed to maternal depression from birth to 6 years and healthy controls. At 9 months and 6 years, mother-child interactions were coded for maternal sensitivity and affect synchrony and salivary oxytocin levels were assessed at 6 years. At preadolescence (11-13 years), children underwent magnetoencephalography (MEG) while exposed to own versus unfamiliar mother-child interaction. Own interaction elicited greater response in beta- and gamma-band oscillations across a wide cluster in temporal and insular cortices, including the Superior Temporal Sulcus, Superior Temporal Gyrus, Inferior Temporal Gyrus, and insula. Beta activations were predicted by maternal sensitivity across early childhood and gamma by affect synchrony. Oxytocin was related to beta response to social cues. Maternal depression impacted child's brain response in two ways. First, maternal depression significantly increased the prevalence of child affective disorder and such children showed no neural differentiation between attachment and non-attachment stimuli. Second, maternal depression decreased maternal sensitivity, affect synchrony, and child oxytocin across early childhood and these were longitudinally associated with aberrant neural response to attachment-specific and social-general cues in preadolescence. Our findings are the first to describe mechanisms by which maternal depression impairs the neural basis of attachment at the transition to adolescence and advocate the need for relationship-focused early interventions.

Effects of opioids on the parental brain in health and disease

The epidemic of opioid use disorder (OUD) directly affects millions of women of child-bearing age. Unfortunately, parenting behaviors - among the most important processes for human survival - are vulnerable to the effects of OUD. The standard of care for pregnant women with OUD is opioid maintenance therapy (OMT), of which the primary objective is to mitigate addiction-related stress. The aim of this review is to synthesize current information specific to pregnancy and parenting that may be affected by OUD. We first summarize a model of the parental brain supported by animal research and human neuroimaging. We then review animal models of exogenous opioid effects on parental brain and behavior. We also present preliminary data for a unifying hypothesis that may link different effects of exogenous opioids on parenting across species and in the context of OMT. Finally, we discuss future directions that may inform research and clinical decision making for peripartum women with OUD.

Birth practices: Maternal-neonate separation as a source of toxic stress

Maternal-neonate separation for human newborns has been the standard of care since the last century; low birth weight and preterm infants are still routinely separated from their mothers. With advanced technology, survival is good, but long-term developmental outcomes are very poor for these especially vulnerable newborns. The poor outcomes are similar to those described for adversity in childhood, ascribed to toxic stress. Toxic stress is defined as the absence of the buffering protection of adult support. Parental absence has been strictly enforced in neonatal care units for many reasons and could lead to toxic stress. The understanding of toxic stress comes from discoveries about our genome and epigenetics, the microbiome, developmental neuroscience and the brain connectome, and life history theory. The common factor is the early environment that gives (a) signals to epigenes, (b) sensory inputs to neural circuits, and (c) experiences for reproductive fitness. For human newborns that environment is direct skin-to-skin contact from birth. Highly conserved neuroendocrine behaviors determined by environment are described in this review. The scientific rationale underlying skin-to-skin contact is presented: autonomic development and regulation of the physiology leads to emotional connection and achieving resilience. Maternal-neonate separation prevents these critical neural processes from taking place, but also channel development into an alternative developmental strategy. This enables better coping in a stressful environment in the short term, but with permanently elevated stress systems that negatively impact mental and physical health in the long term. This may explain the increasing incidence of developmental problems in childhood, and also Developmental Origins of Health and Disease. Arguments are presented that maternal-neonate separation is indeed a source of toxic stress, and some suggestions are offered toward a "zero separation" paradigm.