Caregiving influences on emotional learning and regulation: Applying a sensitive period model

Love on the developing brain: Maternal sensitivity and infants' neural responses to emotion in the dorsolateral prefrontal cortex

Infancy is a sensitive period of development, during which experiences of parental care are particularly important for shaping the developing brain. In a longitudinal study of N = 95 mothers and infants, we examined links between caregiving behavior (maternal sensitivity observed during a mother-infant free-play) and infants' neural response to emotion (happy, angry, and fearful faces) at 5 and 7 months of age. Neural activity was assessed using functional Near-Infrared Spectroscopy (fNIRS) in the dorsolateral prefrontal cortex (dlPFC), a region involved in cognitive control and emotion regulation. Maternal sensitivity was positively correlated with infants' neural responses to happy faces in the bilateral dlPFC and was associated with relative increases in such responses from 5 to 7 months. Multilevel analyses revealed caregiving-related individual differences in infants' neural responses to happy compared to fearful faces in the bilateral dlPFC, as well as other brain regions. We suggest that variability in dlPFC responses to emotion in the developing brain may be one correlate of early experiences of caregiving, with implications for social-emotional functioning and self-regulation. RESEARCH HIGHLIGHTS: Infancy is a sensitive period of brain development, during which experiences with caregivers are especially important. This study examined links between sensitive maternal care and infants' neural responses to emotion at 5-7 months of age, using functional near-infrared spectroscopy (fNIRS). Experiences of sensitive care were associated with infants' neural responses to emotion-particularly happy faces-in the dorsolateral prefrontal cortex.

Leveraging the developmental neuroscience of caregiving to promote resilience among youth exposed to adversity

Early adversity is a major risk factor for the emergence of psychopathology across development. Identifying mechanisms that support resilience, or favorable mental health outcomes despite exposure to adversity, is critical for informing clinical intervention and guiding policy to promote youth mental health. Here we propose that caregivers play a central role in fostering resilience among children exposed to adversity via caregiving influences on children's corticolimbic circuitry and emotional functioning. We first delineate the numerous ways that caregivers support youth emotional learning and regulation and describe how early attachment lays the foundation for optimal caregiver support of youth emotional functioning in a developmental stage-specific manner. Second, we outline neural mechanisms by which caregivers foster resilience-namely, by modulating offspring corticolimbic circuitry to support emotion regulation and buffer stress reactivity. Next, we highlight the importance of developmental timing and sensitive periods in understanding caregiving-related mechanisms of resilience. Finally, we discuss clinical implications of this line of research and how findings can be translated to guide policy that promotes the well-being of youth and families.

From mother to child: How intergenerational transfer is reflected in similarity of corticolimbic brain structure and mental health

BACKGROUND

Intergenerational transfer effects include traits transmission from parent to child. While behaviorally well documented, studies on intergenerational transfer effects for brain structure or functioning are scarce, especially those examining relations of behavioral and neurobiological endophenotypes. This study aims to investigate behavioral and neural intergenerational transfer effects associated with the corticolimbic circuitry, relevant for socioemotional functioning and mental well-being.

METHODS

T1-neuroimaging and behavioral data was obtained from 72 participants (39 mother-child dyads/ 39 children; 7-13 years; 16 girls/ 33 mothers; 26-52 years). Gray matter volume (GMV) was extracted from corticolimbic regions (subcortical: amygdala, hippocampus, nucleus accumbens; neocortical: anterior cingulate, medial orbitofrontal areas). Mother-child similarity was quantified by correlation coefficients and comparisons to random adult-child pairs.

RESULTS

We identified significant corticolimbic mother-child similarity (r = 0.663) stronger for subcortical over neocortical regions. Mother-child similarity in mental well-being was significant (r = 0.409) and the degree of dyadic similarity in mental well-being was predicted by similarity in neocortical, but not subcortical GMV.

CONCLUSION

Intergenerational neuroimaging reveals significant mother-child transfer for corticolimbic GMV, most strongly for subcortical regions. However, variations in neocortical similarity predicted similarity in mother-child well-being. Ultimately, such techniques may enhance our knowledge of behavioral and neural familial transfer effects relevant for health and disease.

A systematic review of interventions to ameliorate the impact of adversity on brain development

Adversity, including abuse, neglect, and poverty, impacts child brain development. However, the developing brain is highly plastic, and some of the impacts of childhood adversity may be mitigated by psychosocial interventions. The purpose of this review is to synthesize literature on neural outcomes of childhood interventions among individuals exposed to adversity. A systematic literature search identified 36 reports of 13 interventions. Overall, these studies provide evidence for experience-dependent plasticity in the developing brain. We synthesize studies in light of three themes. First, there was mixed evidence for a benefit of a younger age at intervention. Second, interventions tended to accelerate functional brain development, but the impact of interventions on the pace of structural brain development was less clear. Third, individual differences in intervention response were difficult to predict, in part due to small samples. However, there was significant variability in intervention type and timing, neuroimaging outcomes, and follow-up timing. Together, the studies reviewed here hold promise for the role of psychosocial interventions in ameliorating the neurodevelopmental consequences of childhood adversity.

Positive parenting moderates associations between childhood stress and corticolimbic structure

Childhood stress has a deleterious impact on youth behavior and brain development. Resilience factors such as positive parenting (e.g. expressions of warmth and support) may buffer youth against the negative impacts of stress. We sought to determine whether positive parenting buffers against the negative impact of childhood stress on youth behavior and brain structure and to investigate differences between youth-reported parenting and caregiver-reported parenting. Cross-sectional behavioral and neuroimaging data were analyzed from 482 youth (39% female and 61% male, ages 10-17) who participated in an ongoing research initiative, the Healthy Brain Network (HBN). Regression models found that youth-reported positive parenting buffered against the association between childhood stress and youth behavioral problems (β = -0.10, P = 0.04) such that increased childhood stress was associated with increased youth behavior problems only for youth who did not experience high levels of positive parenting. We also found that youth-reported positive parenting buffered against the association between childhood stress and decreased hippocampal volumes (β = 0.07, P = 0.02) such that youth who experienced high levels of childhood stress and who reported increased levels of positive parenting did not exhibit smaller hippocampal volumes. Our work identifies positive parenting as a resilience factor buffering youth against the deleterious impact of stressful childhood experiences on problem behaviors and brain development. These findings underscore the importance of centering youth perspectives of stress and parenting practices to better understand neurobiology, mechanisms of resilience, and psychological well-being.

Functional neuroimaging of resilience to trauma: convergent evidence and challenges for future research

Resilience is broadly defined as the ability to adapt successfully following stressful life events. Here, we review functional MRI studies that investigated key psychological factors that have been consistently linked to resilience to severe adversity and trauma exposure. These domains include emotion regulation (including cognitive reappraisal), reward responsivity, and cognitive control. Further, we briefly review functional imaging evidence related to emerging areas of study that may potentially facilitate resilience: namely social cognition, active coping, and successful fear extinction. Finally, we also touch upon ongoing issues in neuroimaging study design that will need to be addressed to enable us to harness insight from such studies to improve treatments for - or, ideally, guard against the development of - debilitating post-traumatic stress syndromes.

Extinction Learning Across Development: Neurodevelopmental Changes and Implications for Pediatric Anxiety Disorders

Alterations in extinction learning relate to the development and maintenance of anxiety disorders across the lifespan. While exposure therapy, based on principles of extinction, can be highly effective for treating anxiety, many patients do not show sufficient improvement following treatment. In particular, evidence suggests that exposure therapy does not work sufficiently for up to 40% of children who receive this evidence-based treatment.Importantly, fear learning and extinction, as well as the neural circuitry supporting these processes, undergo dynamic changes across development. An improved understanding of developmental changes in extinction learning and the associated neural circuitry may help to identify targets to improve treatment response in clinically anxious children and adolescents. In this chapter, we provide a brief overview of methods used to study fear learning and extinction in developmental populations. We then review what is currently known about the developmental changes that occur in extinction learning and related neural circuitry. We end this chapter with a discussion of the implications of these neurodevelopmental changes for the characterization and treatment of pediatric anxiety disorders.

Early stressful experiences are associated with reduced neural responses to naturalistic emotional and social content in children

How do children's experiences relate to their naturalistic emotional and social processing? Because children can struggle with tasks in the scanner, we collected fMRI data while 4-to-11-year-olds watched a short film with positive and negative emotional events, and rich parent-child interactions (n = 70). We captured broad, normative stressful experiences by examining socioeconomic status (SES) and stressful life events, as well as children's more proximal experiences with their parents. For a sub-sample (n = 30), parenting behaviors were measured during a parent-child interaction, consisting of a picture book, a challenging puzzle, and free play with novel toys. We characterized positive parenting behaviors (e.g., warmth, praise) and negative parenting behaviors (e.g., harsh tone, physical control). We found that higher SES was related to greater activity in medial orbitofrontal cortex during parent-child interaction movie events. Negative parenting behaviors were associated with less activation of the ventral tegmental area and cerebellum during positive emotional events. In a region-of-interest analysis, we found that stressful life events and negative parenting behaviors were associated with less activation of the amygdala during positive emotional events. These exploratory results demonstrate the promise of using movie fMRI to study how early experiences may shape emotional, social, and motivational processes.

What is the expected human childhood? Insights from evolutionary anthropology

In psychological research, there are often assumptions about the conditions that children expect to encounter during their development. These assumptions shape prevailing ideas about the experiences that children are capable of adjusting to, and whether their responses are viewed as impairments or adaptations. Specifically, the expected childhood is often depicted as nurturing and safe, and characterized by high levels of caregiver investment. Here, we synthesize evidence from history, anthropology, and primatology to challenge this view. We integrate the findings of systematic reviews, meta-analyses, and cross-cultural investigations on three forms of threat (infanticide, violent conflict, and predation) and three forms of deprivation (social, cognitive, and nutritional) that children have faced throughout human evolution. Our results show that mean levels of threat and deprivation were higher than is typical in industrialized societies, and that our species has experienced much variation in the levels of these adversities across space and time. These conditions likely favored a high degree of phenotypic plasticity, or the ability to tailor development to different conditions. This body of evidence has implications for recognizing developmental adaptations to adversity, for cultural variation in responses to adverse experiences, and for definitions of adversity and deprivation as deviation from the expected human childhood.

Early Life Stress and Neurodevelopment in Adolescence: Implications for Risk and Adaptation

An alarming high proportion of youth experience at least one kind of stressor in childhood and/or adolescence. Exposure to early life stress is associated with increased risk for psychopathology, accelerated biological aging, and poor physical health; however, it is important to recognize that not all youth who experience such stress go on to develop difficulties. In fact, resilience, or positive adaptation in the face of adversity, is relatively common. Individual differences in vulnerability or resilience to the effects of early stress may be represented in the brain as specific patterns, profiles, or signatures of neural activation, structure, and connectivity (i.e., neurophenotypes). Whereas neurophenotypes of risk that reflect the deleterious effects of early stress on the developing brain are likely to exacerbate negative outcomes in youth, neurophenotypes of resilience may reduce the risk of experiencing these negative outcomes and instead promote positive functioning. In this chapter we describe our perspective concerning the neurobiological mechanisms and moderators of risk and resilience in adolescence following early life stress and integrate our own work into this framework. We present findings suggesting that exposure to stress in childhood and adolescence is associated with functional and structural alterations in neurobiological systems that are important for social-affective processing and for cognitive control. While some of these neurobiological alterations increase risk for psychopathology, they may also help to limit adolescents' sensitivity to subsequent negative experiences. We also discuss person-centered strategies that we believe can advance our understanding of risk and resilience to early stress in adolescents. Finally, we describe ways in which the field can broaden its focus to include a consideration of other types of environmental factors, such as environmental pollutants, in affecting both risk and resilience to stress-related health difficulties in youth.

Early Adversity and Development: Parsing Heterogeneity and Identifying Pathways of Risk and Resilience

Adversity early in life is common and is a major risk factor for the onset of psychopathology. Delineating the neurodevelopmental pathways by which early adversity affects mental health is critical for early risk identification and targeted treatment approaches. A rapidly growing cross-species literature has facilitated advances in identifying the mechanisms linking adversity with psychopathology, specific dimensions of adversity and timing-related factors that differentially relate to outcomes, and protective factors that buffer against the effects of adversity. Yet, vast complexity and heterogeneity in early environments and neurodevelopmental trajectories contribute to the challenges of understanding risk and resilience in the context of early adversity. In this overview, the author highlights progress in four major areas-mechanisms, heterogeneity, developmental timing, and protective factors; synthesizes key challenges; and provides recommendations for future research that can facilitate progress in the field. Translation across species and ongoing refinement of conceptual models have strong potential to inform prevention and intervention strategies that can reduce the immense burden of psychopathology associated with early adversity.

Mechanisms of neuroplasticity linking early adversity to depression: developmental considerations

Early exposure to psychosocial adversity is among the most potent predictors of depression. Because depression commonly emerges prior to adulthood, we must consider the fundamental principles of developmental neuroscience when examining how experiences of childhood adversity, including abuse and neglect, can lead to depression. Considering that both the environment and the brain are highly dynamic across the period spanning gestation through adolescence, the purpose of this review is to discuss and integrate stress-based models of depression that center developmental processes. We offer a general framework for understanding how psychosocial adversity in early life disrupts or calibrates the biobehavioral systems implicated in depression. Specifically, we propose that the sources and nature of the environmental input shaping the brain, and the mechanisms of neuroplasticity involved, change across development. We contend that the effects of adversity largely depend on the developmental stage of the organism. First, we summarize leading neurobiological models that focus on the effects of adversity on risk for mental disorders, including depression. In particular, we highlight models of allostatic load, acceleration maturation, dimensions of adversity, and sensitive or critical periods. Second, we expound on and review evidence for the formulation that distinct mechanisms of neuroplasticity are implicated depending on the timing of adverse experiences, and that inherent within certain windows of development are constraints on the sources and nature of these experiences. Finally, we consider other important facets of adverse experiences (e.g., environmental unpredictability, perceptions of one's experiences) before discussing promising research directions for the future of the field.

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

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

Migration-related trauma and mental health among migrant children emigrating from Mexico and Central America to the United States: Effects on developmental neurobiology and implications for policy

Children make up over half of the world's migrants and refugees and face a multitude of traumatic experiences prior to, during, and following migration. Here, we focus on migrant children emigrating from Mexico and Central America to the United States and review trauma related to migration, as well as its implications for the mental health of migrant and refugee children. We then draw upon the early adversity literature to highlight potential behavioral and neurobiological sequalae of migration-related trauma exposure, focusing on attachment, emotion regulation, and fear learning and extinction as transdiagnostic mechanisms underlying the development of internalizing and externalizing symptomatology following early-life adversity. This review underscores the need for interdisciplinary efforts to both mitigate the effects of trauma faced by migrant and refugee youth emigrating from Mexico and Central America and, of primary importance, to prevent child exposure to trauma in the context of migration. Thus, we conclude by outlining policy recommendations aimed at improving the mental health of migrant and refugee youth.