Specifying the Neurobiological Basis of Human Attachment: Brain, Hormones, and Behavior in Synchronous and Intrusive Mothers

Department of Psychology and Gonda Brain Sciences Center, Bar-Ilan University, Ramat-Gan, Israel.
Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology (Impact Factor: 7.05). 08/2011; 36(13):2603-15. DOI: 10.1038/npp.2011.172
Source: PubMed


The mother-infant bond provides the foundation for the infant's future mental health and adaptation and depends on the provision of species-typical maternal behaviors that are supported by neuroendocrine and motivation-affective neural systems. Animal research has demonstrated that natural variations in patterns of maternal care chart discrete profiles of maternal brain-behavior relationships that uniquely shape the infant's lifetime capacities for stress regulation and social affiliation. Such patterns of maternal care are mediated by the neuropeptide Oxytocin and by stress- and reward-related neural systems. Human studies have similarly shown that maternal synchrony--the coordination of maternal behavior with infant signals--and intrusiveness--the excessive expression of maternal behavior--describe distinct and stable maternal styles that bear long-term consequences for infant well-being. To integrate brain, hormones, and behavior in the study of maternal-infant bonding, we examined the fMRI responses of synchronous vs intrusive mothers to dynamic, ecologically valid infant videos and their correlations with plasma Oxytocin. In all, 23 mothers were videotaped at home interacting with their infants and plasma OT assayed. Sessions were micro-coded for synchrony and intrusiveness. Mothers were scanned while observing several own and standard infant-related vignettes. Synchronous mothers showed greater activations in the left nucleus accumbens (NAcc) and intrusive mothers exhibited higher activations in the right amygdala. Functional connectivity analysis revealed that among synchronous mothers, left NAcc and right amygdala were functionally correlated with emotion modulation, theory-of-mind, and empathy networks. Among intrusive mothers, left NAcc and right amygdala were functionally correlated with pro-action areas. Sorting points into neighborhood (SPIN) analysis demonstrated that in the synchronous group, left NAcc and right amygdala activations showed clearer organization across time, whereas among intrusive mothers, activations of these nuclei exhibited greater cross-time disorganization. Correlations between Oxytocin with left NAcc and right amygdala activations were found only in the synchronous group. Well-adapted parenting appears to be underlay by reward-related motivational mechanisms, temporal organization, and affiliation hormones, whereas anxious parenting is likely mediated by stress-related mechanisms and greater neural disorganization. Assessing the integration of motivation and social networks into unified neural activity that reflects variations in patterns of parental care may prove useful for the study of optimal vs high-risk parenting.

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Available from: Ruth Feldman, Oct 10, 2015
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    • "Several exciting studies have now demonstrated that individual differences in parenting behaviors may be based on variations in neural responses to infant stimuli. In one of these studies, mothers at four to six months postpartum were divided into two groups: mothers with high synchronous scores and low intrusiveness scores (synchronous mothers) and mothers with low synchronous scores and high intrusiveness scores (intrusive mothers) (Atzil et al., 2011). Synchronous maternal behaviors, including coordination of gaze, touch, and vocalizations with infants, are interpreted as more sensitive parenting behaviors and are associated with positive infant outcomes. "
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    ABSTRACT: Early mother-infant relationships play important roles in infants' optimal development. New mothers undergo neurobiological changes that support developing mother-infant relationships regardless of great individual differences in those relationships. In this article, we review the neural plasticity in human mothers' brains based on functional magnetic resonance imaging (fMRI) studies. First, we review the neural circuits that are involved in establishing and maintaining mother-infant relationships. Second, we discuss early postpartum factors (e.g., birth and feeding methods, hormones, and parental sensitivity) that are associated with individual differences in maternal brain neuroplasticity. Third, we discuss abnormal changes in the maternal brain related to psychopathology (i.e., postpartum depression, posttraumatic stress disorder, substance abuse) and potential brain remodeling associated with interventions. Last, we highlight potentially important future research directions to better understand normative changes in the maternal brain and risks for abnormal changes that may disrupt early mother-infant relationships. Copyright © 2015. Published by Elsevier Inc.
    Hormones and Behavior 08/2015; DOI:10.1016/j.yhbeh.2015.08.001 · 4.63 Impact Factor
    • "Past research on OT and interactive behavior during the postpartum period was either limited to women from community samples ( e . g . , Atzil et al . , 2011 ; Feldman et al . , 2011 ; Feldman et al . , 2007 ; Feldman et al . , 2012 ; Gordon et al . , 2010a , 2010b ) or clinical samples of depressed women ( Mah et al . , 2014 ; Mah et al . , 2013 ) . To our knowledge , the current study is the first to directly compare the relationship between OT levels and interactive behavior in postpartum"
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    ABSTRACT: Mothers with mood or anxiety disorders exhibit less optimal interactive behavior. The neuropeptide oxytocin (OT) has been linked to more optimal interactive behaviors in mothers without mental illness, and it may play a particularly beneficial role in mothers with mood or anxiety disorders given its antidepressant and anxiolytic functions. We compared the relationship between OT and interactive behavior in mothers with and without mental health problems. Participants included 20 women diagnosed with postpartum mood or anxiety disorders (clinical sample) and 90 women with low levels of depression and anxiety during pregnancy and postpartum (community sample). At 2 months' postpartum, blood was drawn to assess maternal OT levels, and mother-infant interaction was coded for maternal sensitivity, intrusiveness, remoteness, and depressiveness. Clinical mothers exhibited less sensitive, more intrusive, and more depressive interactive behaviors than did community mothers. The groups did not differ in OT levels. Mothers with higher OT levels were less intrusive with their infants. Higher OT levels were associated with less depressive interactive behavior only in clinical mothers. OT was associated with positive interactive behaviors in both groups. In clinical mothers, the calming and soothing effects of OT may promote more relaxed, energetic, and infant-focused interactive behaviors. © 2015 Michigan Association for Infant Mental Health.
    Infant Mental Health Journal 06/2015; 36(4). DOI:10.1002/imhj.21521 · 0.61 Impact Factor
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    • ". In elegant research, fMRI has been used to examine the neurohormonal basis of maternal organizing and entraining behaviors such as maternal gaze and pacing of social cues that influence physiological synchrony, attachment , and maternal interaction style [26]. Our research adds to the body of knowledge regarding development of mother and infant circadian rhythm and synchrony in several ways. "
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    ABSTRACT: Background: Mutual circadian rhythm is an early and essential component in the development of maternal-infant physiological synchrony. Aims: The aim of this to examine the longitudinal pattern of maternal-infant circadian rhythm and rhythm synchrony as measured by rhythm parameters. Study design: In-home dyadic actigraphy monitoring at infant age 4, 8, and 12 weeks. Subjects: Forty-three healthy mother-infant pairs. Outcome measures: Circadian parameters derived from cosinor and non-parametric analysis including mesor, magnitude, acrophase, L5 and M10 midpoints (midpoint of lowest 5 and highest 10 h of activity), amplitude, interdaily stability (IS), and intradaily variability (IV). Results: Mothers experienced early disruption of circadian rhythm, with re-establishment of rhythm over time. Significant time effects were noted in increasing maternal magnitude, amplitude, and IS and decreasing IV (p < .001). Infants demonstrated a developmental trajectory of circadian pattern with significant time effects for increasing mesor, magnitude, amplitude, L5, IS, and IV (p < .001). By 12 weeks, infant phase advancement was evidenced by mean acrophase and M10 midpoint occurring 60 and 43 min (respectively) earlier than at 4 weeks. While maternal acrophase remained consistent over time, infants became increasingly phase advanced relative to mother and mean infant acrophase at 12 weeks occurred 60 min before mother. Mother-infant synchrony was evidenced in increasing correspondence of acrophase at 12 weeks (r = 0.704), L5 (r = 0.453) and M10 (r = 0.479) midpoints. Conclusions: Development of mother-infant synchrony reflects shared elements of circadian rhythm.
    Early Human Development 12/2014; 90(12). DOI:10.1016/j.earlhumdev.2014.09.005 · 1.79 Impact Factor
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