The missing link: mothers' neural response to infant cry related to infant attachment behaviors

Neural correlates of inhibitory control in the context of infant cry and paternal postpartum mental health

BACKGROUND

Inhibitory control, a form of self-regulation, may support sensitive parenting, but has been understudied in new fathers despite their pronounced risk for stress and mental health challenges.

METHODS

This study probed the neural correlates of inhibitory control and its associations to first-time fathers' postpartum mental health, focusing on depressive symptoms, state anxiety, and perceived stress. Six months after their child's birth, 38 fathers self-reported on their mood, anxiety, and stress, and performed a Go/No-Go fMRI task while listening to three sets of sounds (infant cry, pink noise, and silence).

RESULTS

Fathers' behavioral inhibition accuracy was consistent across the sound conditions, but their patterns of neural activation varied. Compared to the pink noise condition, fathers showed heightened engagement in prefrontal regulatory regions when self-regulating during the infant cry and silent conditions. When examining correct trials only, results in visual motor area and primary somatosensory cortex emerged only for infant cry and not for pink noise and silence. Moreover, fathers reporting higher levels of postpartum depression, state anxiety, and perceived stress showed greater activation in prefrontal regions when inhibiting during infant cry or silence.

CONCLUSION

This study is the first to underscore the complex interplay between the neural mechanisms related to inhibitory control and postpartum mental health and stress across varied auditory context, laying the groundwork for future research.

Interbrain substrates of role switching during mother-child interaction

Mother-child interaction is highly dynamic and reciprocal. Switching roles in these back-and-forth interactions serves as a crucial feature of reciprocal behaviors while the underlying neural entrainment is still not well-studied. Here, we designed a role-controlled cooperative task with dual EEG recording to explore how differently two brains interact when mothers and children hold different roles. When children were actors and mothers were observers, mother-child interbrain synchrony emerged primarily within the theta oscillations and the frontal lobe, which highly correlated with children's attachment to their mothers (self-reported by mothers). When their roles were reversed, this synchrony was shifted to the alpha oscillations and the central area and associated with mothers' perception of their relationship with their children. The results suggested an observer-actor neural alignment within the actor's oscillations, which was related to the actor-toward-observer emotional bonding. Our findings contribute to the understanding of how interbrain synchrony is established and dynamically changed during mother-child reciprocal interaction.

Brain circuits for maternal sensitivity and pain involving anterior cingulate cortex among mothers receiving buprenorphine treatment for opioid use disorder

Opioid-induced deficits in maternal behaviors are well-characterized in rodent models. Amid the current epidemic of opioid use disorder (OUD), prevalence among pregnant women has risen sharply. Yet, the roles of buprenorphine replacement treatment for OUD (BT/OUD) in the brain functions of postpartum mothers are unclear. Using functional magnetic resonance imaging (fMRI), we have developed an evolutionarily conserved maternal behavior neurocircuit (MBN) model to study human maternal care versus defensive/aggressive behaviors critical to mother-child bonding. The anterior cingulate gyrus (ACC) is not only involved in the MBN for mother-child bonding and attachment, but also part of an opioid sensitive "pain-matrix". The literature suggests that prescription opioids produce physical and emotional "analgesic" effects by disrupting specific resting-state functional connectivity (rs-FC) of ACC to regions related to MBN. Thus, in this longitudinal study, we report findings of overlapping MBN and pain matrix circuits, for mothers with chronic exposure of BT/OUD. A total of 32 mothers were studied with 6 min rs-FC at 1 month (T1) and 4 months postpartum (T2), including seven on BT/OUD and 25 non-BT/OUD mothers as a comparison group. We analyzed rs-FC between the insula, putamen, and the dorsal anterior cingulate cortex (DACC) and rostral ACC (RACC), as the regions of interest that mediate opioid analgesia. BT/OUD mothers, as compared to non-BT/OUD mothers, showed less left insula-RACC rs-FC but greater right putamen-DACC rs-FC at T1, with these between-group differences diminished at T2. Some of these rs-FC results were correlated with the scores of postpartum parental bonding questionnaire. We found time-by-treatment interaction effects on DACC and RACC-dependent rs-FC, potentially identifying brain mechanisms for beneficial effects of BT, normalizing dysfunction of maternal brain and behavior over the first four months postpartum. This study complements recent studies to ascertain how BT/OUD affects maternal behaviors, mother-child bonding, and intersubjectivity and reveals potential MBN/pain-matrix targets for novel interventions.

Breastfeeding at Any Cost? Adverse Effects of Breastfeeding Pain on Mother-Infant Behavior

Breast milk is considered the ideal infant nutrition, and medical organizations encourage breastfeeding worldwide. Moreover, breastfeeding is often perceived as a natural and spontaneous socio-biological process and one of the fundamental roles of new mothers. While breastfeeding is beneficial, little scientific consideration has been given to its potential psychological challenges. Here, we investigate the phenomenon of breastfeeding pain in mothers and its association with maternal and infant behavioral regulation. During the postpartum weeks, the mother-infant dyad can be considered one allostatic unit directed at infant regulation and development. We hypothesize that pain comprises an allostatic challenge for mothers and will thus impair the capacity for dyadic regulation. To test this, we recruited 71 mothers with varying levels of breastfeeding pain and videotaped them with their infants (2-35 weeks old) during spontaneous face-to-face interactions. We quantified the individual differences in dyadic regulation by behaviorally coding the second-by-second affective expressions for each mother and infant throughout their interactions. We tested the extent to which breastfeeding pain alters affect regulation during mother-infant interactions. We discovered that mothers with severe breastfeeding pain express less affective expressions and less infant-directed gaze during interactive moments of engagement and play than mothers with no or moderate pain. Moreover, infants of mothers experiencing pain during breastfeeding express less affective expressions and more mother-directed gaze while interacting with their mothers than infants of mothers who are not in pain. This demonstrates that the allostatic challenge of maternal pain interferes with the behavioral regulation of both mothers and infants. Since the mother-infant dyad is a codependent allostatic unit, the allostatic challenges of one partner can impact the dyad and thus potentially impact child development, bonding, and mother and infant well-being. The challenges of breastfeeding should be considered in addition to the nutritional advances.

Aberrant resting-state regional activity in patients with postpartum depression

Background

Postpartum depression (PPD) is a common disorder with corresponding cognitive impairments such as depressed mood, memory deficits, poor concentration, and declining executive functions, but little is known about its underlying neuropathology.

Method

A total of 28 patients with PPD and 29 healthy postpartum women were recruited. Resting-state functional magnetic resonance imaging (rs-fMRI) scans were performed in the fourth week after delivery. Individual local activity of PPD patients was observed by regional homogeneity (ReHo) during resting state, and the ReHo value was computed as Kendall's coecient of concordance (KCC) and analyzed for differences between voxel groups. Correlations between ReHo values and clinical variables were also analyzed.

Result

Compared with healthy postpartum women, patients with PPD exhibited significantly higher ReHo values in the left precuneus and right hippocampus. ReHo value was significantly lower in the left dorsolateral prefrontal cortex (dlPFC) and right insula. Furthermore, ReHo values within the dlPFC were negatively correlated with the Edinburgh PPD scale (EPDS) score. The functional connectivity (FC) of the right hippocampus to the left precuneus and left superior frontal gyrus (SFG) was stronger in patients with PPD than that in controls.

Conclusion

The present study provided evidence of aberrant regional functional activity and connectivity within brain regions in PPD, and it may contribute to further understanding of the neuropathology underlying PPD.

Parental protection in fathers with negative caregiving experiences: Heightened amygdala reactivity to infant threatening situations

Parental protection is an important, yet understudied, aspect of parenting behavior. Predictors of the quality of protection and potential underlying neural mechanisms are still unknown. In this study, we examined whether negative caregiving experiences in fathers' own childhood are related to protective behavior and neural reactivity to infant threatening situations. Paternal protective behavior was measured with self- and partner-reported protective behavior and behavioral observations in an experimental set-up (auditory startling task) in 121 first-time fathers (mean age child = 19.35 weeks, SD = 11.27). Neural activation during exposure to videos of infant-threatening (vs. neutral) situations was measured with functional magnetic resonance imaging (fMRI). We found a significant and positive association between negative caregiving experiences and amygdala reactivity to infant-threatening situations. A history of negative caregiving experiences was not significantly related to reported or observed paternal protective behavior. Our findings suggest that fathers with negative caregiving experiences show emotional hyperreactivity to cues of infant threat.

A magnetoencephalography study of first-time mothers listening to infant cries

Studies using magnetoencephalography (MEG) have identified the orbitofrontal cortex (OFC) to be an important early hub for a “parental instinct” in the brain. This complements the finding from functional magnetic resonance imaging studies linking reward, emotion regulation, empathy, and mentalization networks to the “parental brain.” Here, we used MEG in 43 first-time mothers listening to infant and adult cry vocalizations to investigate the link with mother–infant postpartum bonding scores and their level of sleep deprivation (assessed using both actigraphy and sleep logs). When comparing brain responses to infant versus adult cry vocalizations, we found significant differences at around 800–1,000 ms after stimuli onset in the primary auditory cortex, superior temporal gyrus, hippocampal areas, insula, precuneus supramarginal gyrus, postcentral gyrus, and posterior cingulate gyrus. Importantly, mothers with weaker bonding scores showed decreased brain responses to infant cries in the auditory cortex, middle and superior temporal gyrus, OFC, hippocampal areas, supramarginal gyrus, and inferior frontal gyrus at around 100–300 ms after the stimulus onset. In contrast, we did not find correlations with sleep deprivation scores. The significant decreases in brain processing of an infant’s distress signals could potentially be a novel signature of weaker infant bonding in new mothers and should be investigated in vulnerable populations.

Maternal socioeconomic disadvantage, neural function during volitional emotion regulation, and parenting

The transition to becoming a mother involves numerous emotional challenges, and the ability to effectively keep negative emotions in check is critical for parenting. Evidence suggests that experiencing socioeconomic disadvantage interferes with parenting adaptations and alters neural processes related to emotion regulation. The present study examined whether socioeconomic disadvantage is associated with diminished neural activation while mothers engaged in volitional (i.e., purposeful) emotion regulation. 59 mothers, at an average of 4 months postpartum, underwent fMRI scanning and completed the Emotion Regulation Task (ERT). When asked to regulate emotions using reappraisal (i.e., Reappraise condition; reframing stimuli in order to decrease negative emotion), mothers with lower income-to-needs ratio exhibited dampened neural activation in the dorsolateral and ventrolateral PFC, middle frontal and middle temporal gyrus, and caudate. Without explicit instructions to down-regulate (i.e., Maintain condition), mothers experiencing lower income also exhibited dampened response in regulatory areas, including the middle frontal and middle temporal gyrus and caudate. Blunted middle frontal gyrus activation across both Reappraise and Maintain conditions was associated with reduced maternal sensitivity during a mother-child interaction task. Results of the present study demonstrate the influence of socioeconomic disadvantage on prefrontal engagement during emotion regulation, which may have downstream consequences for maternal behaviors.

Less can be more: Fine tuning the maternal brain

PAWLUSKI, J.L., Hoekzema, E., Leuner, B., and Lonstein, J.S. Less can be more: Fine tuning the maternal brain. NEUROSCI BIOBEHAV REV (129) XXX-XXX, 2022. Plasticity in the female brain across the lifespan has recently become a growing field of scientific inquiry. This has led to the understanding that the transition to motherhood is marked by some of the most significant changes in brain plasticity in the adult female brain. Perhaps unexpectedly, plasticity occurring in the maternal brain often involves a decrease in brain volume, neurogenesis and glial cell density that presumably optimizes caregiving and other postpartum behaviors. This review summarizes what we know of the 'fine-tuning' of the female brain that accompanies motherhood and highlights the implications of these changes for maternal neurobehavioral health. The first part of the review summarizes structural and functional brain changes in humans during pregnancy and postpartum period with the remainder of the review focusing on neural and glial plasticity during the peripartum period in animal models. The aim of this review is to provide a clear understanding of when 'less is more' in maternal brain plasticity and where future research can focus to improve our understanding of the unique brain plasticity occurring during matrescence.

A soft baby carrier intervention enhances amygdala responses to infant crying in fathers: A randomized controlled trial

New fathers may grow into their parental role through active involvement in childcare. Spending time in physical contact with the child may promote an adaptive transition to fatherhood. In this randomized controlled trial, we tested the effects of a baby carrier intervention on fathers' hormonal and neural functioning. Using functional magnetic resonance imaging (fMRI), we examined whether infant carrying affects neural reactivity to infant crying in first-time fathers, taking into account the role of the hormone oxytocin as a mediating mechanism and fathers' own childhood experiences as a potential moderating factor. Sixty first-time fathers (infant age M = 11.18 weeks, SD = 2.08) were randomly assigned to a baby carrier intervention group (n = 32 fathers) or a control group (n = 28 fathers). Fathers in the intervention group were instructed to use a baby carrier for three weeks, whereas fathers in the control group were instructed to use a baby seat. Before and after the intervention salivary oxytocin was measured and neural reactivity to infant crying was assessed using fMRI. Results showed that the infant carrier intervention increased amygdala reactivity to infant crying compared to the infant seat users. This effect was most pronounced in fathers with experiences of childhood abuse. The carrier intervention did not affect fathers' oxytocin levels. Our findings indicate that spending time in physical contact with the infant may promote attention to and accurate perception of infant signals, in particular in fathers with more adverse childhood experiences. Soft baby carriers may, therefore, facilitate an adaptive transition to fatherhood.

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.

The Effect of Maternal Depression on Infant Attachment: A Systematic Review

Aims and objectives: The aim of this systematic review was to summarize the key findings of empirical studies assessing the influence of maternal depression on child attachment security measured before 24 months after birth. Method: The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. A literature search was conducted on the EBSCO (Academic Search Complete; Health Source: Nursing/Academic Edition; MEDLINE; PsycARTICLES) and PubMed databases, with infant attachment AND depression as search terms with Boolean operators. Study design or sample size did not affect inclusion. After screening, 29 of the 1510 unique publications originally identified were included in the review. Results: The studies reveal an equivocal association between maternal depression and child attachment security. Our findings indicate that depression had a significant influence on the attachment style almost only when diagnosed by structured interview: Depression measured by self-descriptive questionnaires was unrelated to attachment style. Furthermore, postpartum depression was found to be significant only when measured up to six months after childbirth. Conclusion: The relationship between maternal depression and infant attachment is both complex and dynamic, and the possible negative effects of depression might be compensated by maternal involvement in childcare. Therefore, further studies in this area should employ a reliable methodology for diagnosing depression and a suitable time point for measuring it; they should also adopt a multifactorial and prospective approach. It is important to note that breastfeeding/formula feeding was omitted as a factor in the majority of studies.

Substance use and mothers' neural responses to infant cues

Substance use may influence mothers' responsiveness to their infants and negatively impact the parent-infant relationship. Maternal substance use may co-opt neural circuitry involved in caregiving, thus reducing the salience of infant cues and diminishing the sense of reward experienced by caring for infants. Gaps in understanding exist with regard to the mechanisms by which substance use operates to influence mothers' processing of infant cues and how this translates to caregiving. Therefore, we examined how substance use might relate to maternal neural responses to infant cues using event-related potentials (ERPs). Substance-using (n = 29) and nonsubstance-using (n = 29) mothers viewed photographs of infant faces and heard recordings of infant vocalizations while electroencephalography was recorded simultaneously. Three specific ERP components were used to examine initial processing of infant faces (N170) and cries (N100), and attentional allocation to infant faces and cries (P300). Substance-using mothers did not discriminate facial affect at early encoding stages (N170), were generally slower to orient to infant cries (N100), showed heightened responses to neutral faces (P300), and failed to adaptively differentiate between high-distress versus low-distress cries (P300). These differences may be important to caregiving behaviors associated with the formation of mother-child attachment. Implications are discussed, as are limitations and future directions.

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.

Amygdala and affective responses to infant pictures: Comparing depressed and non-depressed mothers and non-mothers

In many mammalian species, new mothers show heightened positive responsiveness to infants and their cues when they give birth. As is evident from non-human and human studies, the amygdala is a brain region implicated in both the maternal and affective neural circuitry, and is involved in processing socioemotionally salient stimuli. In humans, infants are socially salient stimuli to women, and mothers in particular. Neuroimaging studies investigating the maternal response to infant cues have identified infant-related amygdala function as an important factor in maternal anxiety/depression, in the quality of mothering and in individual differences in the motivation to mother. The present study investigated the effects of maternal status and depression on the subjective affective response and amygdala responsiveness to unfamiliar infants using functional magnetic resonance imaging. Smiling infant pictures were used in a 2 × 2 design comparing four groups of women: mothers and non-mothers, with and without depression (total of 101 women: postpartum depression [PPD] = 32, non-PPD = 25, major depression [MDD] = 15, non-MDD = 29). We undertook an anatomically defined region of interest analysis of the amygdala response for a priori defined group comparisons. We found that mothers rated infants more positively than non-mothers and non-mothers rated non-infant stimuli (scenery) more positively than mothers. In the amygdala, we found that depression elevated response to smiling unfamiliar infants in mothers but had no effect in non-mothers. Within the depressed groups, mothers (PPD) showed an elevated amygdala response to unfamiliar smiling infants compared to depressed non-mothers. Hence, our results indicate that women with PPD show an enhanced amygdala response to affectively positive infant pictures but not to affectively positive (but non-salient) pictures of scenery. Women with depression outside of the postpartum period show no change in amygdala responsiveness to either stimulus categories.

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.

Early postpartum resting-state functional connectivity for mothers receiving buprenorphine treatment for opioid use disorder: A pilot study

Between 1999 and 2014, the prevalence of opioid use disorder (OUD) among pregnant women quadrupled in the USA. The standard treatment for peripartum women with OUD is buprenorphine. However, the maternal behavior neurocircuit that regulates maternal behavior and mother-infant bonding has not been previously studied for human mothers receiving buprenorphine treatment for OUD (BT). Rodent research shows opioid effects on reciprocal inhibition between maternal care and defence maternal brain subsystems: the hypothalamus and periaqueductal gray, respectively. We conducted a longitudinal functional magnetic resonance imaging (fMRI) pilot study in humans to specifically examine resting-state functional connectivity (rs-FC) between the periaqueductal gray and hypothalamus, as well as to explore associations with maternal bonding for BT. We studied 32 mothers who completed fMRI scans at 1 month (T1) and 4 months postpartum (T2), including seven mothers receiving buprenorphine for OUD and 25 non-OUD mothers as a comparison group (CG). The participants underwent a 6-minute resting-state fMRI scan at each time point. We measured potential bonding impairments using the Postpartum Bonding Questionnaire to explore how rs-FC with periaqueductal gray is associated with bonding impairments. Compared to CG, BT mothers differed in periaqueductal gray-dependent rs-FC with the hypothalamus, amygdala, insular cortex and other brain regions at T1, with many of these differences disappearing at T2, suggesting potential therapeutic effects of continuing buprenorphine treatment. In contrast, the "rejection and pathological anger" subscale of the Postpartum Bonding Questionnaire at T1 and T2 was associated with the T1-to-T2 increases in periaqueductal gray-dependent rs-FC with the hypothalamus and amygdala. Preliminary evidence links maternal bonding problems for mothers with OUD early in the postpartum to connectivity between specific care and defence maternal brain circuits, which may be mitigated by buprenorphine treatment. This exploratory study supports a potential mechanism for investigating both the therapeutic benefits and risks of opioids for maternal care and bonding with infants.

Severity of anxiety moderates the association between neural circuits and maternal behaviors in the postpartum period

Neuroimaging research has suggested that activity in the amygdala, center of the socioemotional network, and functional connectivity between the amygdala and cortical regions are associated with caregiving behaviors in postpartum mothers. Anxiety is common in the early postpartum period, with severity ranging from healthy maternal preoccupation to clinical disorder. However, little is known about the influence of anxiety on the neural correlates of early caregiving. We examined these relationships in a community cohort of 75 postpartum women (ages 18-22; predominantly low-SES, minority race) who listened to infant cry sounds while undergoing an fMRI assessment. Maternal self-reported symptoms of anxiety were mostly within the subclinical range. Positive and negative caregiving behaviors during filmed face-to-face mother-infant interactions were coded by independent observers. The results from whole-brain analyses showed that anxiety severity moderated the brain-maternal behavior relationships. Specifically, our results showed that the higher a mother's anxiety, the stronger the association between positive caregiving (i.e., maternal warmth and involvement) and amygdala-right posterior superior temporal sulcus (amygdala-RpSTS) functional connectivity. These results remained significant when we controlled for symptoms of depression and contextual variables. These findings suggest that functional connectivity between the amygdala and a social perception region (RpSTS) plays a particularly important role for anxious mothers in facilitating their positive parenting. These findings extend our understanding of the specific neural circuits that support positive maternal caregiving in the context of maternal anxiety, and they may help inform the future design of personalized and effective interventions.

Limbic-visual attenuation to crying faces underlies neglectful mothering

Neglectful mothering is one of the most common forms of childhood maltreatment, involving a severe disregard of the child's needs, yet little is known about its neural substrate. A child's needs are usually conveyed by signals of distress revealed by crying faces. We tested whether infant and adult crying faces are processed differently in two sociodemographically similar groups of Neglectful (NM) and non-neglectful Control Mothers (CM). We used functional brain imaging to analyze the BOLD response from 43 mothers (23 neglectful and 20 control) while viewing faces from infants and adults (crying and neutral). In NM as compared to CM, the BOLD responses to both infant and adult crying faces were significantly reduced in the cerebellum, lingual, fusiform, amygdala, hippocampus, parahippocampus, and inferior frontal gyrus. The reduced BOLD was also modulated by comorbid psychiatric symptoms. In the CM, frontal activation to infant versus adult crying faces was enhanced, whereas in the NM activation in the anterior cingulate cortex to infant crying was reduced compared to adult crying. The altered neural response to crying faces in NM, showing generic face and infant-specific face processing deficits, could underlie their characteristic poor social abilities as well as their poor response to infant needs, both affecting the caregiving role.

Maternal perception of children's fear: A fMRI study in mothers of preschool children

A secure attachment relationship is facilitated by a mother´s ability to perceive her child´s emotions, especially her child´s fear. Prior studies showed that maternal perception of an own child activated a neural network including amygdala, insula and nucleus accumbens (NAcc). Results for different emotions were inconsistent and there are no reports on children´s fear. The goal of this study was to investigate neural responses of 17 mothers to photos of their own and an unknown preschool child with happy and fearful expressions by functional magnetic resonance imaging (fMRI). Whole brain analyses showed that a fearful (vs. happy) own child elicited larger activity in the visual cortex. Region of interest (ROI) analyses (amygdala, insula, NAcc) revealed stronger responses to a happy (vs. fearful) unknown child, but equally strong responses to one´s own child´s expressions. Moreover, an own (vs. unknown) fearful child elicited larger activity in the insula and NAcc. This suggests that mothers allocated more visual attention towards their own child´s fear, but showed consistent emotional involvement with their own child across expressions. Mothers might respond with stronger empathy and approach motivation towards an own (vs. unknown) fearful child, in line with a key role of fear in the attachment relationship.

Mothers With Postpartum Psychiatric Disorders: Proposal for an Adapted Method to Assess Maternal Sensitivity in Interaction With the Child

About 15% of mothers suffer from postpartum psychiatric disorders, such as depression, anxiety, or psychosis. Numerous studies have shown maternal caregiving behavior to be negatively affected under these circumstances. The current study sets out to shed light on specific caregiving behaviors of affected mothers in the context of parental mental illness at an early stage. There are several methods to assess maternal caregiving behavior in terms of sensitivity. However, all of them have limitations regarding the peculiarities of mothers with postpartum disorders, that is, changes in affect regulation, and the early onset of the disorder postpartum. With the current study, we provide an adapted method to assess maternal sensitivity based on methods recently approved in attachment research. Two groups of mothers, who were either healthy or had different postpartum disorders, were recorded on video during interactions with their infants. Behaviors were rated regarding responsiveness, promptness, appropriateness, intrusiveness, and positive and negative affect. A first analysis revealed an increased number of deficits on all subscales in mothers with postpartum psychiatric disorders as compared to healthy mothers. Depressive mothers with a single diagnosis had lower scores in responsiveness, promptness, and appropriateness and higher scores on intrusiveness as compared to those in healthy mothers. Here, maternal behavior appears more parent-centered, whereas affect seemed to be relatively unharmed. Moreover, as compared to healthy mothers, mothers with comorbid depression and anxiety symptomatology achieved lower scores on responsiveness, appropriateness, and positive affect and higher scores on intrusiveness and negative affect. It is suggested, that increased deficits are related to the severity of illness in mothers with comorbidities. Results on promptness indicate that these mothers are still capable of maintaining higher vigilance to infant cues. Variance in maternal behavior was relatively high in clinical mothers, showing that some of them are well capable of behaving in a sensitive manner toward their child. One strength of our adapted method is that particular aspects of sensitive parent-child interactions are assessed separately. This may shed light on specific behavior patterns of different postpartum psychiatric disorders, which may in turn relate to specific child outcomes. The manual is open for usage, while reliability testing is required.

Brain plasticity in pregnancy and the postpartum period: links to maternal caregiving and mental health

Pregnancy and the postpartum period involve numerous physiological adaptations that enable the development and survival of the offspring. A distinct neural plasticity characterizes the female brain during this period, and dynamic structural and functional changes take place that accompany fundamental behavioral adaptations, stimulating the female to progress from an individual with self-directed needs to being responsible for the care of another life. While many animal studies detail these modifications, an emerging body of research reveals the existence of reproduction-related brain plasticity in human mothers too. Additionally, associations with aspects of maternal caregiving point to adaptive changes that benefit a woman's transition to motherhood. However, the dynamic changes that affect a woman's brain are not merely adaptive, and they likely confer a vulnerability for the development of mental disorders. Here, we review the changes in brain structure and function that a woman undergoes during the peripartum period, outlining associations between these neural alterations and different aspects of maternal care. We additionally discuss peripartum mood disorders and postpartum psychosis, and review the neuroimaging studies that investigate the neural bases of these conditions.

Nature, Nurture, and Attachment: Implications in Light of Expanding Definitions of Parenthood

Recent expansion of the legal definition of parenthood in New York State raises the question of whether the presence of a genetic relationship between a parent and child trumps environmental and interpersonal factors in the formation of a strong, secure attachment bond. The purpose of this paper is to emphasize that attachment between a child and secure attachment figure is inherently biological, and that such biological attachment supersedes the existence of a genetic parent-child relationship. First, the paper provides an overview of attachment and its biological basis. It then discusses the impact on attachment of environmental and interpersonal influences, which current research suggests have the power to alter brain biology. There is no clear evidence that a genetic relationship confers a significant advantage in terms of attachment. This paper proposes that the term "biological parent" be redefined to include anyone with whom a child shares a strong attachment bond.

The maternal brain in women with a history of early-life maltreatment: an imagination-based fMRI study of conflictual versus pleasant interactions with children

BACKGROUND

Early-life maltreatment has severe consequences for the affected individual, and it has an impact on the next generation. To improve understanding of the intergenerational effects of abuse, we investigated the consequences of early-life maltreatment on maternal sensitivity and associated brain mechanisms during mother-child interactions.

METHODS

In total, 47 mothers (22 with a history of physical and/or sexual childhood abuse and 25 without, all without current mental disorders) took part in a standardized real-life interaction with their 7- to 11-year-old child (not abused) and a subsequent functional imaging script-driven imagery task.

RESULTS

Mothers with early-life maltreatment were less sensitive in real-life mother-child interactions, but while imagining conflictual interactions with their child, they showed increased activation in regions of the salience and emotion-processing network, such as the amygdala, insula and hippocampus. This activation pattern was in contrast to that of mothers without early-life maltreatment, who showed higher activations in those regions in response to pleasant mother-child interactions. Mothers with early-life maltreatment also showed reduced functional connectivity between regions of the salience and the mentalizing networks.

LIMITATIONS

Region-of-interest analyses, which were performed in addition to whole-brain analyses, were exploratory in nature, because they were not further controlled for multiple comparisons.

CONCLUSION

Results suggest that for mothers with early-life maltreatment, conflictual interactions with their child may be more salient and behaviourally relevant than pleasant interactions, and that their salience network is poorly modulated by the brain regions involved in mentalizing processes. This activation pattern offers new insights into the mechanisms behind the intergenerational effects of maltreatment and into options for reducing these effects.

Effects of vasopressin on neural processing of infant crying in expectant fathers

In a randomized, double blind, placebo-controlled, within-subject magnetic resonance imaging study, we examined the effect of 20 IU intranasal vasopressin on the neural processing of infant crying in 25 fathers-to-be. We explored whether familial background modulates vasopressin effects, and whether vasopressin differentially affects cry processing coupled with neutral or emotional contextual information. Participants listened to cries accompanied by neutral ('this is an infant') or emotional ('this infant is sick/bored') contextual information, and neutral control sounds ('this is a saw'). Additionally, participants reported on their childhood experiences of parental love-withdrawal and abuse. Infant crying (vs control sounds) was associated with increased activation in the bilateral auditory cortex and posterior medial cortex. No effects of vasopressin were found in this 'cry network'. Exploratory whole-brain analyses suggested that effects of vasopressin in the anterior cingulate cortex, paracingulate gyrus and supplemental motor area were stronger in fathers who experienced lower (vs higher) levels of love-withdrawal. No interaction was observed for abuse. Vasopressin increased activation in response to cries accompanied by emotional vs neutral contextual information in several brain regions, e.g. the cerebellum, brainstem (midbrain), posterior medial cortex, hippocampus, putamen, and insula. Our results suggest that the experience of love-withdrawal may modulate the vasopressin system, influencing effects of vasopressin administration on cry processing. Results further suggest a role for vasopressin in the processing of cry sounds with emotional contextual information.

Enhanced Nogo-P3 amplitudes of mothers compared with non-mother women during an emotional Go/Nogo task

Background

It is known that emotion regulatory responses of humans are changed by the experiences they have, but in particular, they are changed by becoming a mother. A recent study has found how a woman’s emotion regulatory response to a child’s crying changes after becoming a mother. However, mothers’ emotion regulatory responses other than those to children and the association between emotion regulatory response and parental stress are still unknown.

Methods

Eighteen healthy Japanese females (nine mothers and nine non-mothers) participated in the experiment. They performed an emotional Go/Nogo task, with facial expressions of others (angry, happy, and neutral faces) used as emotional stimuli. The percentage of correct responses, response time, and event-related potentials (ERPs) during the task was measured.

Results

This comparison revealed that the mother group had a larger P3 (Nogo-P3) amplitude than the non-mother group when Nogo trials were held. This indicates that in mothers, there was greater activation of the behavioral inhibition-related brain areas than in non-mother women when they inhibited inappropriate behavior following recognition of facial expressions of others. In addition, in the mother group, there was a negative correlation between parental stress levels and Nogo-P3 amplitudes evoked by angry faces. This suggests that there is a relation between the level of parental stress of mothers and their emotion regulatory responses to angry faces.

Conclusions

Our results demonstrate that mothers’ emotion regulatory processes may differ from those of non-mothers in response, not only to a child’s crying but also to expressions of emotions by others, and also suggest that the inhibitory recognition activity of mothers can be affected by parental stress.

Early life social stress and resting state functional connectivity in postpartum rat anterior cingulate circuits

INTRODUCTION

Continued development and refinement of resting state functional connectivity (RSFC) fMRI techniques in both animal and clinical studies has enhanced our comprehension of the adverse effects of stress on psychiatric health. The objective of the current study was to assess both maternal behavior and resting state functional connectivity (RSFC) changes in these animals when they were dams caring for their own young. It was hypothesized that ECSS exposed dams would express depressed maternal care and exhibit similar (same networks), yet different specific changes in RSFC (different individual nuclei) than reported when they were adult females.

METHODS

We have developed an ethologically relevant transgenerational model of the role of chronic social stress (CSS) in the etiology of postpartum depression and anxiety. Initial fMRI investigation of the CSS model indicates that early life exposure to CSS (ECSS) induces long term changes in functional connectivity in adult nulliparous female F1 offspring.

RESULTS

ECSS in F1 dams resulted in depressed maternal care specifically during early lactation, consistent with previous CSS studies, and induced changes in functional connectivity in regions associated with sensory processing, maternal and emotional responsiveness, memory, and the reward pathway, with robust changes in anterior cingulate circuits.

LIMITATIONS

The sample sizes for the fMRI groups were low, limiting statistical power.

CONCLUSION

This behavioral and functional neuroanatomical foundation can now be used to enhance our understanding of the neural etiology of early life stress associated disorders and test preventative measures and treatments for stress related disorders.

Activity changes in the left superior temporal sulcus reflect the effects of childcare training on young female students' perceptions of infants' negative facial expressions

In many developed countries, the number of infants who experience non-parent childcare is increasing, and the role of preschool teachers is becoming more important. However, little attention has been paid to the effects of childcare training on students who are studying to become preschool teachers. We used functional magnetic resonance imaging (fMRI) to investigate whether and how childcare training affects brain responses to infants' facial expressions among young females studying to become preschool teachers. Twenty-seven subjects who attended a childcare training session (i.e., the experimental group) and 28 subjects who did not attend the training (i.e., the control group) participated in this study. The participants went through fMRI scanning twice: before and after the childcare training session. They were presented with happy, neutral, and sad infant faces one by one during fMRI scanning. The present neuroimaging results revealed that the activity patterns of the left superior temporal sulcus (STS) for sad faces were modulated by the interaction between the time point of the data collection and group differences. The present results are the first to highlight the effects of childcare training on the human brain.

Parent-child intervention decreases stress and increases maternal brain activity and connectivity during own baby-cry: An exploratory study

Parental responses to their children are crucially influenced by stress. However, brain-based mechanistic understanding of the adverse effects of parenting stress and benefits of therapeutic interventions is lacking. We studied maternal brain responses to salient child signals as a function of Mom Power (MP), an attachment-based parenting intervention established to decrease maternal distress. Twenty-nine mothers underwent two functional magnetic resonance imaging brain scans during a baby-cry task designed to solicit maternal responses to child's or self's distress signals. Between scans, mothers were pseudorandomly assigned to either MP (n = 14) or control (n = 15) with groups balanced for depression. Compared to control, MP decreased parenting stress and increased child-focused responses in social brain areas highlighted by the precuneus and its functional connectivity with subgenual anterior cingulate cortex, which are key components of reflective self-awareness and decision-making neurocircuitry. Furthermore, over 13 weeks, reduction in parenting stress was related to increasing child- versus self-focused baby-cry responses in amygdala-temporal pole functional connectivity, which may mediate maternal ability to take her child's perspective. Although replication in larger samples is needed, the results of this first parental-brain intervention study demonstrate robust stress-related brain circuits for maternal care that can be modulated by psychotherapy.

Epigenetic and Neural Circuitry Landscape of Psychotherapeutic Interventions

The science behind psychotherapy has garnered considerable interest, as objective measures are being developed to map the patient's subjective change over the course of treatment. Prenatal and early life influences have a lasting impact on how genes are expressed and the manner in which neural circuits are consolidated. Transgenerationally transmitted epigenetic markers as well as templates of enhanced thought flexibility versus evasion can be passed down from parent to child. This influences gene expression/repression (impacting neuroplasticity) and kindling of neurocircuitry which can perpetuate maladaptive cognitive processing seen in a number of psychiatric conditions. Importantly, genetic factors and the compounding effects of early life adversity do not inexorably lead to certain fated outcomes. The concepts of vulnerability and resilience are becoming more integrated into the framework of "differential susceptibility," speaking to how corrective environmental factors may promote epigenetic change and reconfigure neural templates, allowing for symptomatic improvement. Psychotherapy is one such factor, and this review will focus on our current knowledge of its epigenetic and neurocircuitry impact.

Depression alters maternal extended amygdala response and functional connectivity during distress signals in attachment relationship

Maternal attachment-related parenting behaviors require mothers to regulate self-related and child-related distress. Emotion regulation is, in turn, influenced by maternal mood and personal developmental history. In the current study we examined how depressive mood may alter maternal limbic system function and functional connectivity underlying defensive and hedonic motivations. Twenty nine mothers were recruited to undergo a baby-cry task during a functional magnetic resonance imaging (fMRI) scan. Based on self-reported depression symptoms and clinical interview, the participants were grouped as healthy controls (n=15) and currently depressed (n=14). In the baby-cry task, 30s-long auditory stimuli of baby-cry sounds were presented to simulate four conditions: generic baby-cry (Just-Listen), baby-cry as if it were their own child's cry (Your-Baby), baby-cry as if it were themselves (Self), and matched control sounds (Noise). Depressed mothers, as compared to healthy controls, showed greater Self versus Just-Listen responses in left extended amygdala and decreased functional coupling between this left extended amygdala as the seed and nucleus accumbens (NAc) in self-oriented (Self versus Just-Listen) and child-oriented (Your-Baby versus Just-Listen) distress signals. Moreover, the extended amygdala's differential functional connectivity with dorsomedial prefrontal cortex (dmPFC) during the Your-Baby versus Self was increased for depressed mothers and decreased for healthy controls. Thus, depression may affect mothers by increasing baby-cry threat responses and dysregulating associations between threat and heathy child-oriented parenting motivations. These results are discussed in the context of attachment and self-psychology.

Mothers Who Were Neglected in Childhood Show Differences in Neural Response to Their Infant's Cry

The present study used functional magnetic resonance imaging to investigate how a mother's experience of neglect in her own childhood is associated with her neural response to her infant's distress cues. During scanning, 22 high-risk primiparous mothers were exposed to both their own 18-month-old infant's cry sound and a control sound. Mothers' continuous Neglect subscale scores from the Childhood Trauma Questionnaire were examined as a predictor of their neural response to own infant cry > control sound. Mothers who reported high levels of neglect from childhood showed regions of hyperactivation to their infant's cry (relative to control sound) in the anterior and posterior cingulate cortices and insula as well as specific prefrontal (precentral gyrus) and parietal (posterior supramarginal gyrus) areas. These results may suggest how important early life experiences are for future parenting responses and behaviors.

Genetic predispositions and parental bonding interact to shape adults' physiological responses to social distress

Parental bonding and oxytocin receptor (OXTR) gene genotype each influences social abilities in adulthood. Here, we hypothesized an interaction between the two - environmental experience (parental bonding history) and genetic factors (OXTR gene genotype) - in shaping adults' social sensitivity (physiological response to distress). We assessed heart rate and peripheral temperature (tip of the nose) in 42 male adults during presentation of distress vocalizations (distress cries belonging to female human infants and adults as well as bonobo). The two physiological responses index, respectively, state of arousal and readiness to action. Participants' parental bonding in childhood was assessed through the self-report Parental Bonding Instrument. To assess participants' genetic predispositions, buccal mucosa cell samples were collected, and region rs2254298 of the oxytocin receptor gene was analyzed: previous OXTR gene findings point to associations between the G allele and better sociality (protective factor) and the A allele and poorer sociality (risk factor). We found a gene * environment interaction for susceptibility to social distress: Participants with a genetic risk factor (A carriers) with a history of high paternal overprotection showed higher heart rate increase than those without this risk factor (G/G genotype) to social distress.Also, a significant effect of the interaction between paternal care and genotype on nose temperature changes was found. This susceptibility appears to represent an indirect pathway through which genes and experiences interact to shape mature social sensitivity in males.

Evidence for a Caregiving Instinct: Rapid Differentiation of Infant from Adult Vocalizations Using Magnetoencephalography

Crying is the most salient vocal signal of distress. The cries of a newborn infant alert adult listeners and often elicit caregiving behavior. For the parent, rapid responding to an infant in distress is an adaptive behavior, functioning to ensure offspring survival. The ability to react rapidly requires quick recognition and evaluation of stimuli followed by a co-ordinated motor response. Previous neuroimaging research has demonstrated early specialized activity in response to infant faces. Using magnetoencephalography, we found similarly early (100-200 ms) differences in neural responses to infant and adult cry vocalizations in auditory, emotional, and motor cortical brain regions. We propose that this early differential activity may help to rapidly identify infant cries and engage affective and motor neural circuitry to promote adaptive behavioral responding, before conscious awareness. These differences were observed in adults who were not parents, perhaps indicative of a universal brain-based "caregiving instinct."

Neuroanatomical and neurochemical basis of parenting: Dynamic coordination of motivational, affective and cognitive processes

This article is part of a Special Issue "Parental Care". Becoming a parent is arguably the most profound transforming experience in life. It is also inherently very emotionally and physically demanding, such that the reciprocal interaction with the young changes the brain and behavior of the parents. In this review, we examine the neurobiological mechanisms of parenting primarily discussing recent research findings in rodents and primates, especially humans. We argue that it is essential to consider parenting within a conceptual framework that recognizes the dynamics of the reciprocal mother-young relationship, including both the complexity and neuroplasticity of its underlying mechanisms. Converging research suggests that the concerted activity of a distributed network of subcortical and cortical brain structures regulates different key aspects of parenting, including the sensory analysis of infant stimuli as well as motivational, affective and cognitive processes. The interplay among these processes depends on the action of various neurotransmitters and hormones that modulate the timely and coordinated execution of caregiving responses of the maternal circuitry exquisitely attuned to the young's affect, needs and developmental stage. We conclude with a summary and a set of questions that may guide future research.

BDNF Methylation and Maternal Brain Activity in a Violence-Related Sample

It is known that increased circulating glucocorticoids in the wake of excessive, chronic, repetitive stress increases anxiety and impairs Brain-Derived Neurotrophic Factor (BDNF) signaling. Recent studies of BDNF gene methylation in relation to maternal care have linked high BDNF methylation levels in the blood of adults to lower quality of received maternal care measured via self-report. Yet the specific mechanisms by which these phenomena occur remain to be established. The present study examines the link between methylation of the BDNF gene promoter region and patterns of neural activity that are associated with maternal response to stressful versus non-stressful child stimuli within a sample that includes mothers with interpersonal violence-related PTSD (IPV-PTSD). 46 mothers underwent fMRI. The contrast of neural activity when watching children—including their own—was then correlated to BDNF methylation. Consistent with the existing literature, the present study found that maternal BDNF methylation was associated with higher levels of maternal anxiety and greater childhood exposure to domestic violence. fMRI results showed a positive correlation of BDNF methylation with maternal brain activity in the anterior cingulate (ACC), and ventromedial prefrontal cortex (vmPFC), regions generally credited with a regulatory function toward brain areas that are generating emotions. Furthermore we found a negative correlation of BDNF methylation with the activity of the right hippocampus. Since our stimuli focus on stressful parenting conditions, these data suggest that the correlation between vmPFC/ACC activity and BDNF methylation may be linked to mothers who are at a disadvantage with respect to emotion regulation when facing stressful parenting situations. Overall, this study provides evidence that epigenetic signatures of stress-related genes can be linked to functional brain regions regulating parenting stress, thus advancing our understanding of mothers at risk for stress-related psychopathology.

Parental brain: cerebral areas activated by infant cries and faces. A comparison between different populations of parents and not

Literature about parenting traditionally focused on caring behaviors and parental representations. Nowadays, an innovative line of research, interested in evaluating the neural areas and hormones implicated in the nurturing and caregiving responses, has developed. The only way to permit a newborn to survive and grow up is to respond to his needs and in order to succeed it is necessary, first of all, that the adults around him understand what his needs are. That is why adults' capacity of taking care of infants cannot disregard from some biological mechanisms, which allow them to be more responsive to the progeny and to infants in general. Many researches have proved that exist specific neural basis activating in response to infant evolutionary stimuli, such as infant cries and infant emotional facial expression. There is a sort of innate predisposition in human adults to respond to infants' signals, in order to satisfy their need and allow them to survive and become young adults capable of taking care of themselves. This article focuses on research that has investigated, in the last decade, the neural circuits underlying parental behavioral responses. Moreover, the paper compares the results of those studies that investigated the neural responses to infant stimuli under different conditions: familiar versus unknown children, parents versus non-parents and normative versus clinical samples (depression, addiction, adolescence, and PTSD).

Emotion Regulation in Parenthood

Emotion regulation, defined as the capacity to influence one's experience and expression of emotion, is a complex skill now recognized to evolve throughout the lifetime. Here we examine the role of emotion regulation in parenthood, and propose that regulatory function during this period is distinct from the emotion regulation skills acquired and implemented during other periods of life. In this review, we consider the unique demands of caring for a child and recognize that parents have to maintain a regulated state as well as facilitate regulation in their child, especially early in development. We examine neurobiological, hormonal and behavioral shifts during the transition to parenthood that may facilitate parental regulation in response to infant cues. Furthermore, we consider how parents shape emotion regulation in their child, and the clinical implications of regulatory functioning within the parent-child relationship.

In search of neural endophenotypes of postpartum psychopathology and disrupted maternal caregiving

This is a selective review that provides the context for the study of perinatal affective disorder mechanisms and outlines directions for future research. We integrate existing literature along neural networks of interest for affective disorders and maternal caregiving: (i) the salience/fear network; (ii) the executive network; (iii) the reward/social attachment network; and (iv) the default mode network. Extant salience/fear network research reveals disparate responses and corticolimbic coupling to various stimuli based upon a predominantly depressive versus anxious (post-traumatic stress disorder) clinical phenotype. Executive network and default mode connectivity abnormalities have been described in postpartum depression (PPD), although studies are very limited in these domains. Reward/social attachment studies confirm a robust ventral striatal response to infant stimuli, including cry and happy infant faces, which is diminished in depressed, insecurely attached and substance-using mothers. The adverse parenting experiences received and the attachment insecurity of current mothers are factors that are associated with a diminution in infant stimulus-related neural activity similar to that in PPD, and raise the need for additional studies that integrate mood and attachment concepts in larger study samples. Several studies examining functional connectivity in resting state and emotional activation functional magnetic resonance imaging paradigms have revealed attenuated corticolimbic connectivity, which remains an important outcome that requires dissection with increasing precision to better define neural treatment targets. Methodological progress is expected in the coming years in terms of refining clinical phenotypes of interest and experimental paradigms, as well as enlarging samples to facilitate the examination of multiple constructs. Functional imaging promises to determine neural mechanisms underlying maternal psychopathology and impaired caregiving, such that earlier and more precise detection of abnormalities will be possible. Ultimately, the discovery of such mechanisms will promote the refinement of treatment approaches toward maternal affective disturbance, parenting behaviours and the augmentation of parenting resiliency.

The biology of mammalian parenting and its effect on offspring social development

Parents know the transformative nature of having and caring for a child. Among many mammals, giving birth leads from an aversion to infant stimuli to irresistible attraction. Here, we review the biological mechanisms governing this shift in parental motivation in mammals. Estrogen and progesterone prepare the uterus for embryo implantation and placental development. Prolactin stimulates milk production, whereas oxytocin initiates labor and triggers milk ejection during nursing. These same molecules, interacting with dopamine, also activate specific neural pathways to motivate parents to nurture, bond with, and protect their offspring. Parenting in turn shapes the neural development of the infant social brain. Recent work suggests that many of the principles governing parental behavior and its effect on infant development are conserved from rodent to humans.

Mothers' amygdala response to positive or negative infant affect is modulated by personal relevance

Understanding, prioritizing and responding to infant affective cues is a key component of motherhood, with long-term implications for infant socio-emotional development. This important task includes identifying unique characteristics of one's own infant, as they relate to differences in affect valence—happy or sad—while monitoring one's own level of arousal. The amygdala has traditionally been understood to respond to affective valence; in the present study, we examined the potential effect of personal relevance on amygdala response, by testing whether mothers' amygdala response to happy and sad infant face cues would be modulated by infant identity. We used functional MRI to measure amygdala activation in 39 first-time mothers, while they viewed happy, neutral and sad infant faces of both their own and a matched unknown infant. Emotional arousal to each face was rated using the Self-Assessment Manikin Scales. Mixed-effects linear regression models were used to examine significant predictors of amygdala response. Overall, both arousal ratings and amygdala activation were greater when mothers viewed their own infant's face compared with unknown infant faces. Sad faces were rated as more arousing than happy faces, regardless of infant identity. However, within the amygdala, a highly significant interaction effect was noted between infant identity and valence. For own-infant faces, amygdala activation was greater for happy than sad faces, whereas the opposite trend was seen for unknown-infant faces. Our findings suggest that the amygdala response to positive or negative valenced cues is modulated by personal relevance. Positive facial expressions from one's own infant may play a particularly important role in eliciting maternal responses and strengthening the mother-infant bond.

Reactivity, regulation, and reward responses to infant cues among mothers with and without psychopathology: an fMRI review

Despite important progress in understanding the complex caregiving system, developmental research has only recently begun to focus on the mother’s internal affective state and its role in sensitive caregiving behavior. This review will summarize recent findings of functional neuroimaging research to elaborate on the neural components associated with maternal sensitive care or disrupted responsiveness to infant communications. First, maternal emotion reactivity and regulation, as well as maternal reward responsiveness to infant cues, will be reviewed among healthy mothers. Then, emotion and reward-related processes among mothers who display sensitive versus disrupted caregiving will be explored. Finally, these patterns of response will be compared to patterns of response among mothers with psychiatric disorders, including depression, posttraumatic stress disorder, and substance abuse. The aim of this review is to examine whether differences in emotion reactivity and regulation, as well as in the encoding of infant stimuli as rewarding, are related either to maternal psychopathology or to maternal difficulties in responding promptly and appropriately to their infants. A summary of the challenges facing developmental neuroscience research in furthering our understanding of maternal responses to infants will close this review.

Minor structural abnormalities in the infant face disrupt neural processing: a unique window into early caregiving responses

Infant faces elicit early, specific activity in the orbitofrontal cortex (OFC), a key cortical region for reward and affective processing. A test of the causal relationship between infant facial configuration and OFC activity is provided by naturally occurring disruptions to the face structure. One such disruption is cleft lip, a small change to one facial feature, shown to disrupt parenting. Using magnetoencephalography, we investigated neural responses to infant faces with cleft lip compared with typical infant and adult faces. We found activity in the right OFC at 140 ms in response to typical infant faces but diminished activity to infant faces with cleft lip or adult faces. Activity in the right fusiform face area was of similar magnitude for typical adult and infant faces but was significantly lower for infant faces with cleft lip. This is the first evidence that a minor change to the infant face can disrupt neural activity potentially implicated in caregiving.