Coregulation in mother-infant dyads: links to infants' cardiac vagal tone

This investigation explored links between mother-infant coregulated communication patterns and infants' emerging parasympathetic regulatory processes (cardiac vagal tone). Participants included 56 first-time mothers and their 6-mo.-old infants (31 girls, 25 boys). A 4-min. baseline EKG was gathered from the infant and an ensuing 15-min. mother-infant dyadic free-play episode was videotaped and coded using Fogel's 1994 Regional Coding System. This system was developed to describe variations in coregulated features of communication among dyads, ranging from symmetrical patterns to disruptive patterns of coregulation. Analysis suggests a positive link between infants' cardiac vagal tone and more symmetrical features of coregulated communication patterns in mother-infant dyads. Cardiac vagal tone was also negatively correlated with unilateral features of coregulation communication systems. These findings point toward the potential relation between emerging physiological regulatory abilities of infants and the more relational regulatory processes in mother-infant dyads.     

Intentions make a difference: infant responses to still-face and modified still-face conditions

In two studies, 3-, 6- and 9-month-old infants interacted with their mothers during natural, still-face, and modified still-face (i.e., mothers wearing a mask, or drinking from bottle) conditions. Infants were also presented with matching doll conditions to control for the possibility that their responses might be due to changes in superficial perceptual features. Regardless of age, infants displayed negative affect to the still-face, but, in contrast to recent reports, not to the modified still-face conditions. However, whereas infants' positive affect also depended on their mothers' communicative intentions, these responses changed with cognitive maturation. As expected, infant responses to their mothers were significantly different from those to the doll. The implications of these findings for theories of communication are discussed.     

Infant affective responses to mother's still face at 6 months differentially predict externalizing and internalizing behaviors at 18 months

This study investigated (a) stability and change in infant affective responses to the still-face interaction, (b) whether maternal depression affected infant responses, and (c) whether responses to the still-face interaction predicted toddler problem behaviors. Infants (63 girls and 66 boys) of European American mothers (67 depressed and 62 nondepressed) were observed in the still-face interaction at 2, 4, and 6 months. Affect and gaze were coded on a 1-s time base. There were stable individual differences in gazing away and in rates of negative affect. Developmental change occurred only for gazing away, which increased. At 18 months, infants who failed to smile at 6 months in the still-face interaction showed more externalizing-type behaviors than did other toddlers. Infants who failed to cry at 6 months showed fewer internalizing-type behaviors. Mothers' current depressive symptoms and infants' earlier responses to the still-face interaction made independent, comparable contributions to problem behaviors at 18 months.     

Infant brain responses to live face-to-face interaction with their mothers: Combining functional near-infrared spectroscopy (fNIRS) with a modified still-face paradigm

BackgroundNon-invasive imaging techniques, such as fNIRS, allow us to shed light on the neural correlates of infant’s social-emotional development within the context of parent-infant interaction. On a behavioral level, numerous studies have investigated parent-infant interaction employing the still-face paradigm and found that the primary caregiver(s), often the mother, is an important coregulator of the infant’s physiological and behavioral stress response. However, limited information is available on how the infant’s brain reacts to the maternal cues during real-life interaction.MethodsTherefore, the main aim of the current study was to design a fNIRS paradigm to study live mother-infant interaction and to explore the neural correlates of infant affect regulation during real-life dyadic interaction. To this end, a modified still-face paradigm was designed, which consists of live face-to-face mother-infant, and stranger-infant, interaction episodes, including stressful, “still-face” and non-stressful, “happy-face” interaction blocks, combined with infant fNIRS imaging.ResultsHemodynamic brain responses were collected in n = 10 (6 females, mean age 230.2 ± 17.5 days), typically developing infants using the Hitachi ETG-4000 continuous-wave system (22 channels spanning the frontal cortex; 10 Hz system sampling frequency). Infants with usable data (n = 7) showed negative activations, indicated by a decrease in oxygenated hemoglobin, over the middle frontal gyrus in response to happy-face (reunion) interaction with their mothers compared to a female stranger; suggesting deactivation of brain regions associated with affect regulation. We also explored correlations between infant brain responses to maternal interaction and infant characteristics (temperament) as well as experiential/environmental factors (mothers’ self-reported depression symptoms).ConclusionsAlthough the current results are very preliminary, they overall suggest that live design in infant populations is doable and offers unique opportunities to study the neural mechanisms underlying early caregiver(s)-child interaction in a more naturalistic context. Restrictions, and implications, of the methodology are critically discussed.     

Using the Actor-Partner Interdependence Model to assess maternal and infant contributions to mother-infant affective exchanges during the Still-Face Paradigm

This study describes maternal and infant contributions to dyadic affective exchanges during the Still-Face Paradigm (SFP) in an understudied mostly low-income sample. One hundred eleven mothers and their 7-month-old infants were videotaped during the SFP to analyze how a social stressor affects mother-infant positive and negative affective exchanges during interaction. The SFP includes 3 episodes: baseline, maternal still-face, and reunion. Maternal and infant positive and negative affect were scored by masked reliable coders. Data were analyzed using the Actor-Partner Interdependence Model to test the hypotheses that each partner’s affectivity during the baseline episode would predict their own affectivity during the reunion episode (actor effects). We also expected that each partner’s affectivity during the baseline episode would influence the other partner’s affectivity during the reunion episodes (partner effects). After controlling for infant sex and maternal education, results provided evidence for actor effects for maternal and infant positive affect, and for partner effects for maternal baseline positive affect to infant positive affect during the reunion. One significant partner effect was observed for negative affect: Infant negativity during baseline predicted greater maternal negativity during reunion. Findings confirm that both mothers and infants contribute to dyadic affective processes during the SFP but specific findings vary depending on the affective valence in question. Clinical implications and future research are discussed.     

Associations between mother-infant bed-sharing practices and infant affect and behavior during the still-face paradigm

Parents in the United States increasingly report bed-sharing with their infants (i.e., sleeping on a shared sleep surface), but the relationship between bed-sharing and child socioemotional outcomes are not well understood. The current study examines the links between mother-infant bed-sharing at 3 months and infant affect and behavior during a dyadic challenge task at 6 months. Further, we examine nighttime mother-infant contact at 3 months as a possible mechanism that may mediate linkages between bed-sharing and infant outcomes. Using observational data from a sample of 63 mother-infant dyads, we found that infants who bed-shared for any proportion of the observation period at 3 months displayed significantly more self-regulatory behaviors during the still-face episode of the Still-Face Paradigm (SFP) at 6 months, compared to non-bed-sharing infants. Also, infants of mothers who bed-shared for the entire observation period displayed significantly less negativity during the reunion episode than non-bed-sharing infants. There was no evidence that the relations between mother-infant bed-sharing practices and infant affect and behavior during the SFP were mediated through nighttime mother-infant contact. Results suggest that infant regulation at 6 months postpartum may vary based on early nighttime experiences, with bed-sharing potentially promoting more positive and well-regulated behavior during dyadic interaction.     

Individual differences in non-clinical maternal depression impact infant affect and behavior during the still-face paradigm across the first year

Maternal depression can significantly impact mothers’ sensitivity to their infants’ needs as well as infants’ social and emotional development. The still-face paradigm (SFP) is widely used to assess infants’ understanding of the contingency between their own behavior and that of their caregivers, as well as infants’ ability to self-regulate arousal levels during sudden changes in maternal responsiveness. Infants of clinically depressed mothers display blunted levels of negative affect compared to infants of non-depressed mothers during the still-face (SF) phase. However, little is known about whether individual differences in elevated, non-clinical levels of maternal depression similarly affect mother-infant interactions. The current study examines the longitudinal effects of non-clinical maternal depression on infant and maternal behaviors during the SFP. Infants (N = 63) were assessed at 5 and 9 months and maternal depression was assessed at 5 months using the Beck Depression Inventory (BDI). Infants of mothers with elevated levels of depression displayed less negative engagement during the SF phase compared to infants of mothers with lower levels of depression. This effect was present at 5 months, but not at 9 months. Findings demonstrate that non-clinical levels of maternal depressive symptomatology can have a significant impact on infants’ affective regulation during the first half of the first year of life, but this does not necessarily have a long-lasting influence later in infancy. Interventions may want to target mothers with non-clinical depression to promote healthy infant social and emotional development.     

Cocaine exposure is associated with subtle compromises of infants' and mothers' social-emotional behavior and dyadic features of their interaction in the face-to-face still-face paradigm

Prenatal cocaine and opiate exposure are thought to subtly compromise social and emotional development. The authors observed a large sample of 236 cocaine-exposed and 459 nonexposed infants (49 were opiate exposed and 646 nonexposed) with their mothers in the face-to-face still-face paradigm. Infant and maternal behaviors were microanalytically coded. No opiate-exposure effects were detected. However, mothers of cocaine-exposed infants showed more negative engagement than other mothers. The cocaine-exposed dyads also showed higher overall levels of mismatched engagement states than other dyads, including more negative engagement when the infants were in states of neutral engagement. Infants exposed to heavier levels of cocaine showed more passive-withdrawn negative engagement and engaged in more negative affective matching with their mothers than other infants. Although effect sizes were small, cocaine exposure, especially heavy cocaine exposure, was associated with subtly negative interchanges, which may have a cumulative impact on infants' later development and their relationships with their mothers.     

A dynamic system analysis of dyadic flexibility and stability across the Face-to-Face Still-Face procedure: Application of the State Space Grid

The Face-to-Face Still-Face (FFSF) paradigm allows to study the mother–infant dyad as a dynamic system coping with social stress perturbations. The State Space Grid (SSG) method is thought to depict both flexibility and stability of the dyad across perturbations, but previous SSG evidence for the FFSF is limited. The main aims were: (1) to investigate mother–infant dyadic flexibility and stability across the FFSF using the SSG; (2) to evaluate the influence of dyadic functioning during Play on infant Still-Face response and of infant stress response in affecting dyadic functioning during Reunion. Forty 4-month-old infants and their mothers were micro-analytically coded during a FFSF and eight SSG dyadic states were obtained. Dyadic flexibility and attractor states were assessed during Play and Reunion. Infants’ stress response was coded as negative engagement during the Still-Face episode. Two dyadic states, “maternal hetero-regulation” and “affective mismatch”, showed significant changes in the number of visits from Play to Reunion. During Play “maternal positive support to infant play” emerged as attractor state, whereas during Reunion a second attractor emerged, namely “affective mismatch”. Dyadic affective mismatch during Play correlated with infants’ negative engagement during Still-Face, whereas infants’ response to Still-Face resulted in minor social matching during Reunion. Findings provide new insights into the flexible, yet stable, functioning of the mother–infant dyad as a dynamic system. Evidence of a reciprocal influence between dyadic functioning and infant social stress response are discussed.     

From biological rhythms to social rhythms: Physiological precursors of mother-infant synchrony

Links between neonatal biological rhythms and the emergence of interaction rhythms were examined in 3 groups (N = 71): high-risk preterms (HR; birth weight <1,000 g), low-risk preterms (LR; birth weight =1,700-1,850 g), and full-term (FT) infants. Once a week for premature infants and on the 2nd day for FT infants, sleep-wake cyclicity was extracted from 4-hr observations and cardiac vagal tone was measured. At term age, infant orientation was tested with the Neonatal Behavior Assessment Scale. At 3 months, arousal modulation and emotion regulation were assessed, and mother-infant synchrony was computed from microanalysis of face-to-face interactions using time-series analysis. Sleep-wake amplitudes showed a developmental leap at 31 weeks gestation, followed by a shift in vagal tone at 34 weeks gestation. At term, differences among FT, LR, and HR infants were observed for biological rhythms in a linear-decline pattern. Sleep-wake cyclicity, vagal tone, newborn orientation, and arousal modulation were each uniquely predictive of mother-infant synchrony. The organization of physiological oscillators appears to lay the foundation for the infant's capacity to partake in a temporally matched social dialogue.     

Facial expressions and vagal tone of infants of depressed and non-depressed mothers

Mothers classified as ‘depressed’, ‘non-depressed’ or ‘low scoring’ on the Beck Depression Inventory and their 3-month-old infants were videotaped during 3-minute face-to-face play interactions. Infants' facial expressions were coded using the AFFEX facial expression coding system and their EKG was recorded during the interactions to assess the relationship between cardiac measures and facial expressivity. Infants of both ‘depressed’ and ‘low scoring’ mothers showed significantly more sad and anger expressions and fewer interest expressions than infants of nondepressed mothers. Cardiac vagal tone, (quantified from the amplitude of respiratory sinus arrhythmia) was correlated with infants' joy and interest expressions and with self-comfort behaviours in the non-depressed and low scoring groups, but not in the depressed group. The results suggest that matermal depression affects infants' affective state and appearance as well as their biobehavioural emotional regulation systems.     

祖辈共同看护背景下母亲和祖辈将心比心、母子依恋与婴幼儿认知的关系:一个有调节的中介模型

本研究探究了祖辈将心比心、母亲将心比心、母子依恋与婴幼儿认知之间的关系,并提出了一个有调节的中介模型。对37名婴幼儿（平均年龄18.24 ±3.34个月）及其母亲和祖母进行研究,研究工具包括将心比心编码方案、依恋行为Q分类和贝利婴幼儿发展量表（第二版）。结果表明：（1）母亲将心比心与母子依恋、婴幼儿认知呈显著正相关,母子依恋与婴幼儿认知呈显著正相关;（2）母子依恋在母亲将心比心与婴幼儿认知发展之间存在中介效应,且该中介过程的前半路径受到祖辈将心比心的调节。当祖辈将心比心水平较高时,母亲将心比心对母子依恋存在显著的正向预测作用。本文是在中国特殊的社会背景下开展的研究,结果为祖辈共同看护这一普遍现象对婴幼儿发展的影响提供了证据支持。     

Child and mother cardiac vagal tone: continuity, stability, and concordance across the first 5 years

In this prospective longitudinal study, vagal tone and heart period were measured at 2 months and at 5 years in children and their mothers to evaluate the development of vagal regulation at rest and during an environmental task. Child baseline vagal tone and heart period were discontinuous; mother baseline vagal tone was discontinuous, but heart period was continuous. Group mean baseline-to-task change in vagal tone and heart period were continuous in both children and mothers. Children reached adult levels of baseline vagal tone by 5 years and did not differ from their mothers in baseline-to-task change in vagal tone or heart period. Baseline vagal tone tended to be stable, but baseline heart period and baseline-to-task change in vagal tone and heart period were unstable in children; both were stable in mothers. Baseline-to-task change in vagal tone showed consistent child-mother concordance. These findings contribute to understanding psychophysiological development, especially the ontogenesis of the vagal system and its regulatory capacity.     

Children's emotion regulation: Self-report and physiological response to peer provocation

The authors examined the notion that children's emotion regulation (ER) is a uniform skill by (a) investigating the concordance between self-report of ER and physiological measures and by (b) examining ER in a specific context (e.g., peer provocation) and context-free manner (e.g., during a semistructured interview of ER abilities). Seventy-two children in middle childhood (average age = 9 years) participated. Time-locked measures of heart rate reactivity and recovery were obtained in response to provoking comments, and vagal regulation was measured throughout the provocation session. Children who reported greater dysregulation showed increased heart rate reactivity to provocative comments (i.e., steeper heart rate slope) but no difference in heart rate recovery. The context-free but not the context-specific self-report measure was associated with a failure to suppress vagal tone. Implications for ER measurement and children's peer relations are discussed.     

Language experiences and vocabulary development in Dominican and Mexican infants across the first 2 years

We longitudinally investigated parental language context and infants' language experiences in relation to Dominican American and Mexican American infants' vocabularies. Mothers provided information on parental language context, comprising measures of parents' language background (i.e., childhood language) and current language use during interviews at infants' birth. Infants' language experiences were measured at ages 14 months and 2 years through mothers' reports of mothers' and fathers' engagement in English and Spanish literacy activities with infants and mothers' English and Spanish utterances during videotaped mother-infant interactions. Infants' vocabulary development at 14 months and 2 years was examined using standardized vocabulary checklists in English and Spanish. Both parental language context and infants' language experiences predicted infants' vocabularies in each language at both ages. Furthermore, language experiences mediated associations between parental language context and infants' vocabularies. However, the specific mediation mechanisms varied by language.     

“Hey mom, look at me!”

The degree to which infant and maternal characteristics were related to maternal psychological distress and play competence was examined in 40 mother preterm and full-term dyads. Measures of maternal psychological distress, self-efficacy, infant temperament, and mother-infant interaction in a play situation, were obtained at 4 months corrected for prematurity. Results revealed that maternal self-efficacy was the strongest correlate of maternal psychological distress but was not related to maternal play competence. Interaction effects for unadaptable temperament and infant behavioral involvement were found in the regressions predicting both maternal psychological distress and maternal play competence. Mothers of more adaptable and less behaviorally involved infants reported greater psychological distress and exhibited greater play competence than mothers of more adaptable and involved infants. The results suggest that a lack of concordance between mothers' perceptions of their infants' behavior and actual behavioral experiences adversely affects mothers' affect and the quality of their play interactions.     

Individual differences in vagal regulation moderate associations between daily affect and daily couple interactions

Previous research suggests that cardiac vagal regulation (indexed by respiratory sinus arrhythmia, or RSA) provides a physiological substrate for affect regulation, which presumably underlies adaptive interpersonal functioning.The authors tested these associations in the context of daily interactions between 68 cohabiting couples. Participants underwent a laboratory assessment of RSA during rest and also during a series of psychological stressors. Subsequently, they kept daily measures of affect and interaction quality for 21 days. Individual differences in baseline and stress levels of RSA moderated within-person associations between daily affect and the quality of couple interactions. The pattern of results differed for women versus men. Men with lower vagal tone or higher vagal reactivity had stronger associations between daily negative affect and daily negative interactions, and men with higher vagal tone had more positive daily interactions overall. Women with higher vagal tone had stronger associations between daily positive affect and daily positive interactions.     

Infant responses to maternal still-face at 4 and 9 months

This study investigated developmental changes in infant responses to maternal still-face (SF) situations. Infants (21 males and 25 females) of Japanese mothers were observed in a face-to-face SF paradigm, comprising four phases (normal/SF/normal/SF), at two infant ages (4 and 9 months). The infants' facial expression, gaze direction, and vocalization were coded in both SF and normal interaction conditions. The results indicated that infants at both ages showed a decrease in displaying positive facial expression and gazing at their mothers during SF conditions. The 4-month-old displayed emotional expression and directed their gaze toward their mothers more frequently than the 9-month-old. However, the 9-month-old vocalized more often in SF situations, attempting to elicit responses from their mothers. The "carry-over" effect was observed only in 9-month-old. The results were discussed in the context of developmental changes in infants' social skills to cope with an emotionally stressful situation.     

Comorbid depression and heart rate variability as predictors of aggressive and hyperactive symptom responsiveness during inpatient treatment of conduct‐disordered,ADHD boys

The primary objective of the present study was to assess the utility of (1) comorbid depression and (2) parasympathetic influence on cardiac function as markers for treatment response among aggressive preadolescent males. Inpatient records of 53 patients with conduct disorder and attention deficit hyperactivity disorder (17 with a comorbid depressive disorder) were examined, including an intake electrocardiogram and daily tallies of several indices of aggressive behavior across 3 weeks of stay. The relations of comorbid depression, heart rate variability, and residualized heart rate (primarily of sympathetic origin) to treatment response were assessed through analyses of linear growth functions. Significant vagal tone by diagnostic status interactions were obtained for both frequency and duration indices of aggression, whereby nondepressed patients with high vagal tone deteriorated and depressed patients with high vagal tone improved during hospitalization. No such relation was found for attention deficit hyperactivity disorder symptoms. Patients in the comorbid group also exhibited greater heart rate variability than their nondepressed counterparts. Furthermore, residualized heart rate was predictive of maternal substance use and paternal incarcerations. These findings suggest complex relations among treatment response, comorbid depression, and emotion regulation in male preadolescents with severe behavior disorders. Additionally, the differential prediction afforded by vagal tone and residualized heart rate underscores the importance of assessing both parasympathetic and sympathetic indices of cardiac function as distinct physiological markers. Aggr. Behav. 26:425–441, 2000. © 2000 Wiley‐Liss, Inc.