The Effect of Maternal Mirroring Behavior on Infants’ Early Social Bidding During the Still-Face Task

Learning how to learn from social feedback: The origins of early vocal development

Infants' prelinguistic vocalizations reliably organize vocal turn-taking with social partners, creating opportunities for learning to produce the sound patterns of the ambient language. This social feedback loop supporting early vocal learning is well-documented, but its developmental origins have yet to be addressed. When do infants learn that their non-cry vocalizations influence others? To test developmental changes in infant vocal learning, we assessed the vocalizations of 2- and 5-month-old infants in a still-face interaction with an unfamiliar adult. During the still-face, infants who have learned the social efficacy of vocalizing increase their babbling rate. In addition, to assess the expectations for social responsiveness that infants build from their everyday experience, we recorded caregiver responsiveness to their infants' vocalizations during unstructured play. During the still-face, only 5-month-old infants showed an increase in vocalizing (a vocal extinction burst) indicating that they had learned to expect adult responses to their vocalizations. Caregiver responsiveness predicted the magnitude of the vocal extinction burst for 5-month-olds. Because 5-month-olds show a vocal extinction burst with unfamiliar adults, they must have generalized the social efficacy of their vocalizations beyond their familiar caregiver. Caregiver responsiveness to infant vocalizations during unstructured play was similar for 2- and 5-month-olds. Infants thus learn the social efficacy of their vocalizations between 2 and 5 months of age. During this time, infants build associations between their own non-cry sounds and the reactions of adults, which allows learning of the instrumental value of vocalizing.

Influences of infants' and mothers' contingent vocal responsiveness on young infants' vocal social bids in the Still Face Task

Infants' social bids in the still face phase of the Still Face Task demonstrate their emerging sense of self agency as these behaviors happen in the absence of the partner's social overtures. The study examined the role of infants' contingent responsiveness to their mothers in social interactions on their social bidding to the mother when she becomes unresponsive. Social bids are non-distress vocalizations or smiles while looking at the unresponsive partner. Infants and their mothers longitudinally engaged in the Still Face Task when infants were one, two, and three months. At two months, infant non-distress vocalizations and smiles and contingent vocal and smiling responsiveness increased in the initial interactive phase and vocal and smile social bids increased in the still face phase. Infant contingent vocal responsiveness predicted infant vocal social bids but infant contingent smiling responsiveness did not predict infant smile social bids. Infant contingent vocal responsiveness was a stronger predictor than infant non-distress vocalizations per se of infant vocal social bids at two and three months. However, maternal contingent vocal responsiveness was the primary predictor of infant vocal social bids at these ages. Maternal contingent responsiveness to infant behavior allows infants to sense their agency in affecting their mothers' behavior. Yet infants are active participants, becoming contingently responsive to their mothers, which facilitates their awareness that they are effective agents in instigating social interaction, as demonstrated by social bids.

Intersubjectivity and the Emergence of Words

Intersubjectivity refers to two non-verbal intersubjective relations infants experience during their first year that are precursors to the emergence of words. Trevarthen, a pioneer in the study of intersubjectivity, referred to those relations as primary and secondary intersubjectivity. The former, a dyadic coordination between the infant and her caregiver, begins at birth. The latter, a triadic coordination that develops around 9 months, allows the infant and a caregiver to share attention to particular features of the environment. Secondary intersubjectivity is crucial for an infant’s ability to begin to produce words, at around 12 months. Much research on the social and cognitive origins of language has focused on secondary intersubjectivity. That is unfortunate because it neglects the fact that secondary intersubjectivity and the emergence of words are built on a foundation of primary intersubjectivity. It also ignores the evolutionary origins of intersubjectivity and its uniquely human status. That unique status explains why only humans learn words. This article seeks to address these issues by relating the literature on primary intersubjectivity, particularly research on bi-directional and contingent communication between infants and mothers, to joint attention and ultimately to words. In that context, we also discuss Hrdy’s hypothesis about the influence of alloparents on the evolution of intersubjectivity.

The impact of a mother-infant intervention on parenting and infant response to challenge: A pilot randomized controlled trial with adolescent mothers in El Salvador

A pilot randomized controlled trial (RCT) was conducted in El Salvador of an intervention ('Thula Sana') previously shown to enhance maternal sensitivity and infant security of attachment in a South African sample. In El Salvador, trained community workers delivered the intervention from late pregnancy to 6 months postpartum as part of a home-visiting programme. The sample comprised 64 pregnant adolescent women, aged 14-19 years, living in predominantly rural settings. They were randomised to receive either the intervention or normal care. Demographic information was collected at baseline and, immediately post-intervention, blind assessments were made of parental sensitivity and infant emotion regulation. The intervention was found to have a substantial positive impact on maternal sensitivity. Further, compared to control group, infants in the intervention group showed more regulated behaviour: in a social challenge task they showed more attempts to restore communication, and in a non-social challenge task they showed more social and goal-directed behaviour. This replication and extension of the South African findings in a small El Salvador sample shows promise and justifies the conduct of a large-scale RCT in a Central or South American context.

Imitation recognition and its prosocial effects in 6-month old infants

The experience of being imitated is theorised to be a driving force of infant social cognition, yet evidence on the emergence of imitation recognition and the effects of imitation in early infancy is disproportionately scarce. To address this lack of empirical evidence, in a within-subjects study we compared the responses of 6-month old infants when exposed to ipsilateral imitation as opposed to non-imitative contingent responding. To examine mediating mechanisms of imitation recognition, infants were also exposed to contralateral imitation and bodily imitation with suppressed emotional mimicry. We found that testing behaviours-the hallmark of high-level imitation recognition-occurred at significantly higher rates in each of the imitation conditions compared to the contingent responding condition. Moreover, when being imitated, infants showed higher levels of attention, smiling and approach behaviours compared to the contingent responding condition. The suppression of emotional mimicry moderated these results, leading to a decrease in all social responsiveness measures. The results show that imitation engenders prosocial effects in 6-month old infants and that infants at this age reliably show evidence of implicit and high-level imitation recognition. In turn, the latter can be indicative of infants' sensitivity to others' intentions directed toward them.

Mothers of children with autism spectrum disorders: Play behaviors with infant siblings and social responsiveness

Mother-infant interactions are a proximal process in early development and may be especially salient for children who are at risk for social difficulties (i.e. infant siblings of children with autism spectrum disorder). To inform how indices of maternal behaviors may improve parent-mediated interventions designed to mitigate autism spectrum disorder risk, the present study explored maternal social responsiveness ratings and social behaviors during dyadic play interactions. Dyads were recruited from families with at least one older child with autism spectrum disorder (high-risk group, n = 90) or families with no history of autism spectrum disorder (low-risk group, n = 62). As part of a prospective study, interactions were coded when infant siblings were 6, 9, and 12 months of age, for gaze, affect, vocalizations, and multimodal bids or responses (i.e. social smiles). Maternal social responsiveness was indexed via the Social Responsiveness Scale. Mothers in both risk groups had comparable Social Responsiveness Scale scores and social behaviors during play. Two maternal behaviors emerged as positive correlates of infant social behaviors and are thus of high relevance to parent-mediated interventions. Specifically, more maternal positive affect and the use of multimodal bids or responses were associated with more infant positive affect, vocalizations, gaze to face, and multimodal bids or responses.

The Effects of Maternal Mirroring on the Development of Infant Social Expressiveness: The Case of Infant Cleft Lip

Parent-infant social interactions start early in development, with infants showing active communicative expressions by just two months. A key question is how this social capacity develops. Maternal mirroring of infant expressions is considered an important, intuitive, parenting response, but evidence is sparse in the first two months concerning the conditions under which mirroring occurs and its developmental sequelae, including in clinical samples where the infant's social expressiveness may be affected. We investigated these questions by comparing the development of mother-infant interactions between a sample where the infant had cleft lip and a normal, unaffected, comparison sample. We videotaped dyads in their homes five times from one to ten weeks and used a microanalytic coding scheme for maternal and infant behaviours, including infant social expressions, and maternal mirroring and marking responses. We also recorded maternal gaze to the infant, using eye-tracking glasses. Although infants with cleft lip did show communicative behaviours, the rate of their development was slower than in comparison infants. This group difference was mediated by a lower rate of mirroring of infant expressions by mothers of infants with cleft lip; this effect was, in turn, partly accounted for by reduced gaze to the infant's mouth, although the clarity of infant social expressions (indexed by cleft severity) and maternal self-blame regarding the cleft were also influential. Results indicate the robustness of parent-infant interactions but also their sensitivity to specific variations in interactants' appearance and behaviour. Parental mirroring appears critical in infant social development, likely supported by the mirror neuron system and underlying clinical and, possibly, cultural differences in infant behaviour. These findings suggest new avenues for clinical intervention.