An automated, data-driven approach to children's social dynamics in space and time.

Most children first enter social groups of peers in preschool. In this context, children use movement as a social tool, resulting in distinctive proximity patterns in space and synchrony with others over time. However, the social implications of children's movements with peers in space and time are difficult to determine due to the difficulty of acquiring reliable data during natural interactions. In this article, we review research demonstrating that proximity and synchrony are important indicators of affiliation among preschoolers and highlight challenges in this line of research. We then argue for the advantages of using wearable sensor technology and machine learning analytics to quantify social movement. This technological and analytical advancement provides an unprecedented view of complex social interactions among preschoolers in natural settings, and can help integrate young children's movements with others in space and time into a coherent interaction framework.

Sing to me, baby: Infants show neural tracking and rhythmic movements to live and dynamic maternal singing.

Infant-directed singing has unique acoustic characteristics that may allow even very young infants to respond to the rhythms carried through the caregiver's voice. The goal of this study was to examine neural and movement responses to live and dynamic maternal singing in 7-month-old infants and their relation to linguistic development. In total, 60 mother-infant dyads were observed during two singing conditions (playsong and lullaby). In Study 1 (n = 30), we measured infant EEG and used an encoding approach utilizing ridge regressions to measure neural tracking. In Study 2 (n =40), we coded infant rhythmic movements. In both studies, we assessed children's vocabulary when they were 20 months old. In Study 1, we found above-threshold neural tracking of maternal singing, with superior tracking of lullabies than playsongs. We also found that the acoustic features of infant-directed singing modulated tracking. In Study 2, infants showed more rhythmic movement to playsongs than lullabies. Importantly, neural coordination (Study 1) and rhythmic movement (Study 2) to playsongs were positively related to infants' expressive vocabulary at 20 months. These results highlight the importance of infants' brain and movement coordination to their caregiver's musical presentations, potentially as a function of musical variability.

To the Operating Room! Positive Effects of a Healthcare Clown Intervention on Children Undergoing Surgery.

In the present study we examined the positive effects of a healthcare clown intervention on children undergoing surgeries, and the role parent-child relationships may play in their effectiveness. Children between 5 and 12 years, who were scheduled to undergo elective surgical procedures in a large university hospital, were randomly assigned to an intervention group (IG; n = 35) that was visited by a healthcare clown, and a control group (CG; n = 27) that received treatment as usual (i.e., company of parents before the surgery). Children in both groups were videotaped and the videos were later used to rate their activity, arousal, emotional expressivity, and vocalizations. Additionally, children and parents rated their mood and perceived quality of life at several points during the procedure, and parents reported their perceptions of the relationship with their children. Results showed that children in the IG showed more positive emotions and vocalizations than children in the CG. Parents of children in the IG also reported more positive mood than parents of children in the CG. In contrast, children in the CG reported higher quality of life than children in the IG. Importantly, analyses showed considerable effects of the parent-child relationship on all outcome measures. Results of the present study demonstrate that a healthcare clown intervention had some positive effects on behaviors and mood of hospitalized children and their parents. Importantly, our findings also suggest that we need to consider the pre-existing "relationship microcosmos" that the clowns enter when assessing their effectiveness in the hospital.

Comparing Online Webcam- and Laboratory-Based Eye-Tracking for the Assessment of Infants' Audio-Visual Synchrony Perception.

Online data collection with infants raises special opportunities and challenges for developmental research. One of the most prevalent methods in infancy research is eye-tracking, which has been widely applied in laboratory settings to assess cognitive development. Technological advances now allow conducting eye-tracking online with various populations, including infants. However, the accuracy and reliability of online infant eye-tracking remain to be comprehensively evaluated. No research to date has directly compared webcam-based and in-lab eye-tracking data from infants, similarly to data from adults. The present study provides a direct comparison of in-lab and webcam-based eye-tracking data from infants who completed an identical looking time paradigm in two different settings (in the laboratory or online at home). We assessed 4-6-month-old infants (n = 38) in an eye-tracking task that measured the detection of audio-visual asynchrony. Webcam-based and in-lab eye-tracking data were compared on eye-tracking and video data quality, infants' viewing behavior, and experimental effects. Results revealed no differences between the in-lab and online setting in the frequency of technical issues and participant attrition rates. Video data quality was comparable between settings in terms of completeness and brightness, despite lower frame rate and resolution online. Eye-tracking data quality was higher in the laboratory than online, except in case of relative sample loss. Gaze data quantity recorded by eye-tracking was significantly lower than by video in both settings. In valid trials, eye-tracking and video data captured infants' viewing behavior uniformly, irrespective of setting. Despite the common challenges of infant eye-tracking across experimental settings, our results point toward the necessity to further improve the precision of online eye-tracking with infants. Taken together, online eye-tracking is a promising tool to assess infants' gaze behavior but requires careful data quality control. The demographic composition of both samples differed from the generic population on caregiver education: our samples comprised caregivers with higher-than-average education levels, challenging the notion that online studies will per se reach more diverse populations.

Studying parent-child interaction with hyperscanning.

Recent research suggests that parent-child interactions influence children's brain development, both in terms of structure and function. However, the neurobiological processes underlying this association have yet to be explored. In the present chapter, we will introduce "hyperscanning" as an upcoming approach to study social interactions between parent and child. We suggest that hyperscanning is especially suitable to examine interpersonal dynamics, such as neural entrainment to communicative signals and interpersonal synchronization of brain activities. Despite the manifold potentials of hyperscanning, the growing field is still facing various challenges, including methodological limitations, which we will also address in this chapter. We will then illustrate how the insights gained so far from hyperscanning studies assessing parent-child interactions can inform research on the development of early social cognition, including social impairments. Hyperscanning has the potential to deepen our understanding of how parent-child interactions can support healthy child development.

Neurobehavioral Interpersonal Synchrony in Early Development: The Role of Interactional Rhythms.

Social interactions are essential for understanding others' actions and their mental and affective states. Specifically, interpersonal coordination - also referred to as synchrony - allows actors to adjust their behaviors to one another and thus demonstrate their connectedness to each other. Much behavioral research has demonstrated the primacy of mutually synchronized social exchanges in early development. Additionally, new methodological advances now allow us to examine interpersonal synchrony not only at the behavioral and physiological but also neural level. Nevertheless, it remains unclear how infants and their caregivers actually achieve interpersonal synchrony in their exchanges. Here we discuss recent evidence showing that adults provide rhythmical information during early social interactions with their infants, such as affective touch and singing. We propose that entrainment to these social rhythms underlies the formation of interpersonal synchrony and thus stimulates reciprocal interactions between infants and their caregivers.

The role of oxytocin in early mother-infant interactions: Variations in maternal affect attunement.

The aim of the present research was to investigate the relationship between oxytocin and maternal affect attunement, as well as the role of affect attunement in the relationship between oxytocin and infant social engagement during early mother-infant interactions. Forty-three mother-infant dyads participated in the present study when infants were 4 months. They were observed during (1) a situation where no communication took place and (2) a natural interaction between mother and infant. During this procedure, three saliva samples from mothers and their infants were collected to determine their levels of oxytocin at different time points. Maternal affect attunement (maintaining attention, warm sensitivity) and infant interactive behaviors (gaze, positive, and negative affect) were coded during the natural interaction. Results indicated that overall maternal oxytocin functioning was negatively related to her warm sensitivity, while infant oxytocin reactivity together with maternal affect attunement were associated with infant positive social engagement with their mothers. Specifically, infant oxytocin reactivity was significantly related to their gazes at mother, but only for infants of highly attuned mothers. These results point to the complex role oxytocin plays in parent-infant interactions while emphasizing the need to analyze both overall oxytocin functioning as well as reactivity as different indices of human affiliative behavior.

Moving developmental social neuroscience toward a second-person approach.

Infants' cognitive development and learning rely profoundly on their interactions with other people. In the first year, infants become increasingly sensitive to others' gaze and use it to focus their own attention on relevant visual input. However, infants are not passive observers in early social interactions, and these exchanges are characterized by high levels of contingency and reciprocity. Wass and colleagues offer first insights into the neurobehavioral dynamics of caregiver-infant interactions, demonstrating that caregivers' scalp-recorded theta band activity responds to their infant's changes in attention, and parental brain activation is associated with infants' sustenance of attention. This research opens up entirely new ways of exploring caregiver-infant interactions and to understand early social attention as a reciprocal and dynamic process.

The Games Infants Play: Social Games During Early Mother-Infant Interactions and Their Relationship With Oxytocin.

The present study examined early social game routines during natural face-to-face mother-infant interactions and their relationship with oxytocin. Forty-three mother-infant dyads were observed, when infants were 4 months old, during a procedure involving a baseline and a natural interaction, where mothers were instructed to interact with their infants as they would at home. During this procedure four saliva samples from mothers and infants were collected to determine levels of oxytocin at different time points. Social game routines and infant social engagement (gaze, positive, and negative affect) were coded during the natural interaction. Social games were observed in 76.7% of the mother-infant dyads, and 46 different types of games were identified. Mothers initiated games to re-engage infants significantly more often than when infants were already engaged with them. During the games, infants showed more positive affect and less negative affect in comparison to the rest of the interaction. Finally, maternal increase in oxytocin from before to after the natural interaction was positively correlated with game rate and time spent in games, while infant increase in oxytocin from before to after the natural interaction was inversely related to game rate. These results indicate that social games are an inherent part of early mother-infant interactions, and their occurrence is associated with oxytocin of both infants and mothers.

Not Just Being Lifted: Infants are Sensitive to Delay During a Pick-Up Routine.

In the present study we observed whether infants show online adjustments to the mother's incipient action by looking at their sensitivity to changes as the pick-up unfolded. Twenty-three 3-month-old infants and their mothers were observed in the lab, where mothers were instructed (1) to pick-up their infants as they usually did (normal pick-up), and then (2) to delay the pick-up for 6 s after placing their hands on the infants' waist (delayed pick-up). In both Normal and Delayed conditions infant's body tension, affective displays and gaze shifts were coded during three phases: Approach, Contact, and Lift. Additionally, a measure of infants' head support in terms of head lag at the beginning and end of Lift was computed. Results showed that during normal pick-up infants tensed up their body during the Approach phase and increased their tension during contact, maintaining it through Lift; their head was also supported and in line with their body during Lift. When the pick-up was delayed, infants also tensed their body during Approach, yet this tension did not increase during the Contact phase and was significantly lower at Lift. Their head support was also lower in the Delayed condition and they shifted their gazes away from their mothers' face more often than in the Normal condition. These results suggest that infants are sensitive to changes of the timing of the pick-up sequence, which in turn may have affected their contribution to the interaction.

Anticipatory adjustments to being picked up in infancy.

Anticipation of the actions of others is often used as a measure of action understanding in infancy. In contrast to studies of action understanding which set infants up as observers of actions directed elsewhere, in the present study we explored anticipatory postural adjustments made by infants to one of the most common adult actions directed to them - picking them up. We observed infant behavioural changes and recorded their postural shifts on a pressure mat in three phases: (i) a prior Chat phase, (ii) from the onset of Approach of the mother's arms, and (iii) from the onset of Contact. In Study 1, eighteen 3-month-old infants showed systematic global postural changes during Approach and Contact, but not during Chat. There was an increase in specific adjustments of the arms (widening or raising) and legs (stiffening and extending or tucking up) during Approach and a decrease in thrashing/general movements during Contact. Shifts in postural stability were evident immediately after onset of Approach and more slowly after Contact, with no regular shifts during Chat. In Study 2 we followed ten infants at 2, 3 and 4 months of age. Anticipatory behavioural adjustments during Approach were present at all ages, but with greater differentiation from a prior Chat phase only at 3 and 4 months. Global postural shifts were also more phase differentiated in older infants. Moreover, there was significantly greater gaze to the mother's hands during Approach at 4 months. Early anticipatory adjustments to being picked up suggest that infants' awareness of actions directed to the self may occur earlier than of those directed elsewhere, and thus enable infants' active participation in joint actions from early in life.

Variations in 10-month-old infant imitation of people and things.

To explore 10-month-old infants' abilities to engage in intentional imitation, they were shown a human agent, a non-human agent (stuffed animal), and a surrogate object (mechanical pincers) model actions on objects. The tendency of infants to perform the target act was compared in several situations: (a) after test items were manipulated but the target action was not shown, (b) after the target act was demonstrated successfully, and (c) after the target act was demonstrated unsuccessfully. Although infants imitated the successful actions of human and non-human agents, they completed the unsuccessful actions of humans only. Toward the surrogate object infants did not respond differentially. These findings suggest that although infant may mimic the actions of human and non-human agents, they only engage in intentional imitation with people.

The role of maternal affect attunement in dyadic and triadic communication.

The influence of maternal affect attunement on the relationship between gaze monitoring during dyadic communication at 3 months and coordinated attention during triadic communication at 5, 7 and 10 months was examined in a longitudinal study. Although most infants engaged in gaze monitoring at 3 months and in coordinated attention at 5, 7 and 10 months, a regression analysis revealed that gaze monitoring at 3 months significantly predicted coordinated attention at 10 months only when maternal affect attunement was high. These findings are discussed in terms of theories that emphasize the role of social interaction in the development of meaningful communication and continuity in mental state awareness during the first year of life.

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.

Contingency, imitation, and affect sharing: Foundations of infants' social awareness.

Predictions about the role of contingency, imitation, and affect sharing in the development of social awareness were tested in infants during natural, imitative, and yoked conditions with their mothers at 5 and 13 weeks of age. Results showed that at both ages, infants of highly attuned mothers gazed, smiled, and vocalized positively more during the natural than during the imitative and yoked conditions, whereas they increased negative vocalizations during the yoked conditions. In contrast, infants of less attuned mothers did not differentiate between the conditions, except at 13 weeks when these infants increased their gazes during the imitative condition. Whereas contingency and imitation draw infant attention to conspecifics, affective communication appears to lay the foundation for infants' social awareness.