Dynamics of frontal alpha asymmetry in mother-infant dyads: Insights from the Still Face Paradigm

The parent-infant dynamic has a foundational role in emotion regulation development. Electroencephalography (EEG) hyperscanning from mother-infant dyads can provide an unprecedented window into inter-brain dynamics during the parent-infant exchange. This potential depends on the feasibility of hyperscanning with dyads in emotionally taxing contexts. We sought to demonstrate feasibility of hyperscanning from 10 mother-infant dyads during the Still Face Procedure (SFP). We measured frontal alpha asymmetry (FAA) to elucidate ongoing regulatory dynamics and considered maternal caregiving quality as a window into dyads’ history. Results showed dyads exhibited a rightward shift in FAA over the course of SFP, indicating growing negative emotionality and desire to withdraw. Results also showed growing variability in FAA for infants over the course of SFP, indicating less active emotional control as stress ensued. Variability was especially low for mothers during periods when asked to be emotionally unavailable, suggesting active control to match the task demands. Dyads with a more responsive mother exhibited higher (more left) FAA relative to dyads with a less responsive mother, which might reflect a more positive emotional experience overall. We raise important methodological and theoretical questions that hyperscanning during SFP can address, such as the developmental origins of trait-like self-regulatory dispositions.     

The Still-Face Paradigm and bidirectionality: Associations with maternal sensitivity,self-esteem and infant emotional reactivity

The Still-Face Paradigm (SFP) is a structured stressful event within which researchers have investigated the influence of maternal psychological and behavioral characteristics on infant behavior. The present investigation contributes to this body of work by examining the joint contributions of maternal and child behavioral and affective characteristics on subsequent behaviors and affectations following the SFP. A sample of non-clinically depressed mothers and their infants (n = 31) engaged in a modified Still-Face Paradigm (SFP), followed by a period of toy play. These interactions were videotaped and behaviorally coded along the following dimensions: maternal sensitivity prior to the SFP and during toy play, infant negative emotional reactivity during the still-face, and infant resistance during the reunion phase. Additionally, mothers reported global self-esteem and this was examined as a predictor of infant behavior. Results revealed significant bidirectional influences such that maternal self-esteem predicted infant emotional reactivity, maternal sensitivity pre-SFP predicted infant resistance during the reunion phase, and infant resistance predicted subsequent levels of maternal sensitivity. Indirect effects were also examined, and provided additional support for bidirectionality in mother–infant interactions. Implications for clinical practice are discussed in light of these findings.     

Attention of 4-month infants to discrepancy and babyishness

A set of four facial stimuli derived from the Bolton standards of craniofacial development representing a human male at 6 months, 3, 8, and 18 years of age were used in a test of Lorenz's concept of babyishness and of the discrepancy hypothesis. Each 4-month-old subject was habituated to a criterion with one of the four stimuli and then presented with one of the four as a new stimulus. The design and analysis permitted the response to a new stimulus to be broken down into a component attributable to the physical characteristics of the new stimulus and a part attributable to its discrepancy from the familiar standard. The data revealed longer looking at the infant facial stimulus, but no difference in a rating of affect accompanying fixation. This lent partial support to the babyishness concept for infant subjects. Both fixation and affect increased monotonically with magnitude of discrepancy. The increasing rather than curvilinear result presumably derived from the failure of these stimuli (which were common to the infant's experience) to generate extreme levels of subjective uncertainty.     

Comparing emotional reactivity and regulation in infants born ELGA and VLGA

Emotional reactivity and regulation behaviors were compared in infants born extremely low gestational age (ELGA) and very low gestational age (VLGA) during the still-face procedure. Infants born ELGA demonstrated greater emotional reactivity and displayed less frequent gaze avoidance, more frequent gestures, and more self-comforting behaviors.     

Behavioral strategies for emotion regulation in toddlers: associations with maternal involvement and emotional expressions

Ninety-four mothers and their 18- or 24-month-old children participated in four laboratory episodes designed to elicit fear or anger. Mothers’ behavior was constrained for the first part of each episode; mothers were then instructed to help their children. Toddlers’ behavioral strategies differed as a function of maternal involvement and as a function of the emotion-eliciting context. Only some of the behavioral strategies assumed to minimize expressions of distress truly did so; other behaviors showed maintenance effects on fear and anger expressions. The different pattern of results for the fear and frustration episodes highlights the importance of examining behavioral strategies across contexts designed to elicit different emotions.     

The influence of maternal anxiety and depression symptoms on fNIRS brain responses to emotional faces in 5- and 7-month-old infants

Greater relative right (versus left) frontal cortical activation to emotional faces as measured with alpha power in the electroencephalogram (EEG), has been considered a promising neural marker of increased vulnerability to psychopathology and emotional disorders. We set out to explore multichannel fNIRS as a tool to investigate infants’ frontal asymmetry responses (hypothesizing greater right versus left frontal cortex activation) to emotional faces as influenced by maternal anxiety and depression symptoms during the postnatal period. We also explored activation differences in fronto-temporal regions associated with facial emotion processing. Ninety-one typically developing 5- and 7-month-old infants were shown photographs of women portraying happy, fearful and angry expressions. Hemodynamic brain responses were analyzed over two frontopolar and seven bilateral cortical regions subdivided into frontal, temporal and parietal areas, defined by age-appropriate MRI templates. Infants of mothers reporting higher negative affect had greater oxyhemoglobin (oxyHb) activation across all emotions over the left inferior frontal gyrus, a region implicated in emotional communication. Follow-up analyses indicated that associations were driven by maternal depression, but not anxiety symptoms. Overall, we found no support for greater right versus left frontal cortex activation in association with maternal negative affect. Findings point to the potential utility of fNIRS as a method for identifying altered neural substrates associated with exposure to maternal depression in infancy.     

The effects of joint attention on object processing in 4- and 9-month-old infants

In this study, we examined the effects of joint attention on object processing in 4- and 9-month-old infants. An adult experimenter differed social cues while speaking to infants about a novel object. Only 9-month-olds showed evidence of enhanced object processing following a joint attention interaction.     

Electrophysiological evidence for the understanding of maternal speech by 9-month-old infants

Early word learning in infants relies on statistical, prosodic, and social cues that support speech segmentation and the attachment of meaning to words. It is debated whether such early word knowledge represents mere associations between sound patterns and visual object features, or reflects referential understanding of words. By measuring an event-related brain potential component known as the N400, we demonstrated that 9-month-old infants can detect the mismatch between an object appearing from behind an occluder and a preceding label with which their mother introduces it. Differential N400 amplitudes have been shown to reflect semantic priming in adults, and its absence in infants has been interpreted as a sign of associative word learning. By setting up a live communicative situation for referring to objects, we demonstrated that a similar priming effect also occurs in young infants. This finding may indicate that word meaning is referential from the outset of word learning and that referential expectation drives, rather than results from, vocabulary acquisition in humans.     

Association of maternal smoking during pregnancy and infant neurobehavioral status

The association of maternal smoking during pregnancy with neurobehavioral status was examined in 344 Japanese infants. Based on a questionnaire, their mothers were classified into three groups, Nonsmokers, Exsmokers, and Smokers. The Neonatal Behavioral Assessment Scale was administered three days after birth. Among the three groups, on the seven clusters and their 28 behavioral subscales there were no significant differences. The infants of Smokers had lower scores than those of Exsmokers and Nonsmokers on two behavioral items, general tone and peak of excitement. General tone remained significant after adjustment for covariates.     

Infant physiological regulation and maternal risks as predictors of dyadic interaction trajectories in families with a preterm infant

This longitudinal study examined predictors of rates of growth in dyadic interaction quality in children born preterm who did not experience significant neurological findings during neonatal intensive care unit (NICU) hospitalization. Multiple methods were used to collect data from 120 preterm infants (48% girls, 52% boys) and their mothers. Infant heart rate variability (HRV), gestational age, neonatal health, feeding route, and maternal socioeconomic (SES) risks were assessed at NICU discharge (mean of 36 weeks postconception). Mother-child interactions were observed at 4, 9, 16, and 24 months postterm and analyzed with hierarchical linear modeling. On average, children's quality of play, interest, and attention increased over time while their dysregulation and irritability decreased, whereas average maternal positive affect and involvement declined in quality (ps < .05), although there was individual variation in rates of change. Mothers of infants with higher postfeeding HRV (i.e., vagal regulation) exhibited less decrease in positive affect and involvement between 4 months and 24 months, compared with mothers of infants with lower HRV (p < .05). Although infants with higher postfeeding HRV showed less positive affect and communication at 4 months, they exhibited significantly greater increases in positive affect and social competence and decreases in dysregulation and irritability between 4 months and 24 months, compared with infants with lower HRV (ps < .05). Dyads experiencing more SES risks showed less optimal interactions at 4 months; this difference remained as children grew older (ps < .05). Results have implications for our understanding of social development in preterm infants.     

Interference Effects in a Numerical Stroop Paradigm in 9- to 12-year-old Children with ADHD-C

Attention deficit hyperactivity disorder (ADHD) is characterized by deficient self-regulation, poor attentional control, and poor response inhibition. To date, however, the extent to which these deficits affect basic interference control remains a matter of controversy. Secondly, ADHD has been reported to be associated with arithmetic deficits. It remains unclear whether such deficits are a secondary consequence of the above-mentioned characteristics of ADHD or whether basic numerical magnitude representations are also affected. In the present study we attempted to investigate these issues using a basic numerical interference paradigm.

Nine- to twelve-year-old children with ADHD-C (attention-deficit hyperactivity-disorder combined type) and control children without ADHD (each n = 16) were presented with two digits of possibly different physical sizes (e.g., 3 7). This numerical Stroop task requires subjects to make a magnitude classification concerning either the physical or the numerical stimulus dimension. The irrelevant dimension can be congruent (same response), incongruent (different response), or neutral (no response association).

Children with ADHD-C performed worse than control children in most analyses. The most important finding was a significant interaction of congruity effects with group in the numerical comparison task. Children with ADHD-C tended to show larger congruity and interference effects than controls, and these were not attributable to a speed-accuracy trade-off.

The results might reflect differential processing speeds, or a different degree of automatic activation of physical and numerical magnitudes in children with and without ADHD-C. Alternative explanations, such as insufficient inhibition of selective (domain-specific) attention are also discussed.     

Applicability and attachment findings of the Strange Situation Paradigm in infants with visual impairment

Attachment studies with diverse populations enrich the understanding of infants’ socioemotional development by documenting both universal and idiosyncratic aspects of attachment. Given the effects of attachment in children's socioemotional outcomes, such studies are necessary to investigate the impact of children's sensory impairments on attachment development. Yet, very little attachment research has focused on infants with visual impairment (VI infants), a population in which infant–caregiver emotional exchanges through visual means are reduced/absent. We investigated the applicability of the Strange Situation Paradigm (SSP), with added instructions to compensate for degraded visual input, in 20 VI infants (with no additional disabilities and who were receiving developmental counseling). In all but 1 of the SSPs coded, VI infants displayed observable attachment behavior that was classifiable. Nineteen VI infants showed attachment by 12 months of age. Across the ages tested (fractional age range = 0.9–2.33 months), most VI infants’ attachment patterns were classified as secure and organized.     

The association between maternal interaction and infant cortisol stress reactivity among preterm and full term infants at 4 months adjusted age

The purpose of this study was to assess the association between maternal interactive behavior and infant cortisol stress reactivity in response to the Still Face paradigm (SF) in a cohort of four-month old infants (adjusted age) born preterm (<32 weeks gestation, N = 22) compared with infants born full term (>37 weeks gestation, N = 28). Infant cortisol reactivity was calculated as area under the curve (AUC) from baseline to the third cortisol sample (30 min post-SF) using the trapezoidal rule, while the percent of time mothers spent using a contingent interaction style was measured (0–100%) during episodes 1 (Play; baseline), 3 (Reunion#1), and 5 (Reunion#2) while mother-infant dyads participated in the SF paradigm. We hypothesized that because infants born preterm are at increased risk for dysregulation, they would show, compared to full-term infants, a blunted stress response, involving under-responsiveness. We found blunted cortisol stress reactivity among the preterm infants. We also found that mothers of preterm infants demonstrated less contingent maternal interaction during Renion#1 of the SF; and that contingent maternal interaction at Reunion#2 of the SF was protective against cortisol stress reactivity in response to the SF. However, we did not find that the influence of maternal interaction on cortisol reactivity was moderated by gestational age group (full term vs preterm): the association between contingent maternal interaction and stress reactivity was similar for both gestational groups across episodes. In order to improve self-regulation and longer term social and cognitive developmental outcomes in medically at-risk infants, future research is warranted to determine how these findings relate to infants’ stress reactions in naturalistic settings, and the directionality and temporal relationship between cortisol stress responses and maternal interactive behavior.     

Interpersonal and emotional processes in generalized anxiety disorder analogues during social interaction tasks

Persons with chronic worry and generalized anxiety disorder (GAD) report maladaptive social cognitions, interpersonal behaviors, and emotional regulation. Because research has neither investigated these processes in actual social situations nor explored whether they take heterogeneous forms, the present study provides the first attempt to do so in a laboratory investigation. GAD analogue participants and nonanxious controls interacted with confederates in an unstructured collaborative story construction task and an emotional disclosure task with standardized confederate behavior. In both tasks, relative to controls, some GAD analogues highly overestimated, whereas others markedly underestimated, their negative (Hostile-Submissive) interpersonal impact on confederates. Although GAD analogues, as a group, exhibited greater sad affect during disclosures than controls, their openness during disclosures and liking by confederates varied with their level of misestimation of negative interpersonal impact. Results underscore the need to further explore interpersonal processes in chronic worriers and how they may exacerbate or maintain dysfunction.     

Spontaneous head positions in infants during the first 9 postnatal months

The developmental organization of spontaneous head positioning over the first 9 postnatal months of life was investigated in a study of 35 infants. Head positions assumed by infants while at rest were recorded at 11 observation period: at 1 week, 2 weeks, 4 weeks of age, and every 4 weeks thereafter until the infant was 36 weeks old. Results indicated an overall tendency toward a head-right position, which was strongest during the neonatal period, but declined with age. The head-right position bias was qualified by familial handedness.     

Effects of maternal depression in the Still-Face Paradigm: A meta-analysis

The Still-Face Paradigm (SFP) enables researchers to examine the quality of mother-infant interactions. In typical infants, a classic still-face effect (SFE) has been confirmed whereby infants demonstrate reduced positive affect (PA), reduced gaze (GA), and increased negative affect (NA). Recently, the SFP has been used to examine the effect of maternal depression upon infant behaviour. However, the nature and consistency of the behavioural responses of infants of depressed mothers during the SFP remains unclear. In the current meta-analysis, we examined whether or not infants of depressed mothers demonstrate the classic SFE, as well as whether or not these infants display the same levels of PA, NA, and GA as their counterparts with non-depressed mothers. Results revealed that infants of depressed mothers display the classic SFE like infants of their non-depressed counterparts. However, infants of depressed mothers also demonstrated significantly higher levels of PA during the still-face episode. One potential interpretation of this finding is that infants prior experience of similar, depressed interactions with their mothers, encourages them to amplify their positive attachment signals in order to engage maternal attention and response. Alternatively, or additionally, infants of depressed mothers could be using PA in order to regulate their own NA.     

Two-month-old infants of depressed mothers show mild, delayed and persistent change in emotional state after non-contingent interaction

The aim of this study was to explore how early infants show different responses to non-contingent maternal behavior according to their past history of relations with their mother. Two groups of 2-month-olds interacted with their mother who was assessed as depressed (group 1) or non-depressed (group 2). Although they received a continuous image and voice of their mothers, the infants were presented either a 30-s contingent maternal communication (live episode 1) or a thirty second non-contingent episode (replay of prior maternal communication), or again a 30-s contingent live episode (live2). The lower percentage of negative facial expressions displayed during replay by infants of depressed mothers suggests on one hand that they are less sensitive to a non-contingent maternal behavior than infants of non-depressed mothers. However, within group comparisons demonstrate a notable difference: while infants of non-depressed mothers show a U curve of smile, infants of depressed mothers show decreasing smile throughout the three episodes. Taken together, these results plead in favour of an other profile of sensitivity displayed by infants of depressed mothers. Instead of the strong but short-term reaction of infants of non-depressed mothers, the response of infants of depressed mothers appeared to be a mild, delayed and more persistent change in emotional state. These findings are discussed in the light of possible cognitive and social incidence of passive avoidance of stressful events in infants of depressed mothers.     

Televised social interaction and object learning in 14- and 18-month-old infants

We examined object learning in infants who viewed a televised adult speaking about a novel toy in videos that varied in the social cues provided. Novelty preference in following test trials differed as a function of televised social cues in 18-month-old, but not 14-month-old infants.     

Face detection in complex visual displays: an eye-tracking study with 3- and 6-month-old infants and adults

The ability to detect and prefer a face when embedded in complex visual displays was investigated in 3- and 6-month-old infants, as well as in adults, through a modified version of the visual search paradigm and the recording of eye movements. Participants (N=43) were shown 32 visual displays that comprised a target face among 3 or 5 heterogeneous objects as distractors. Results demonstrated that faces captured and maintained adults' and 6-month-olds' attention, but not 3-month-olds' attention. Overall, the current study contributes to knowledge of the capacity of social stimuli to attract and maintain visual attention over other complex objects in young infants as well as in adults.