Dyadic and triadic skills in preterm and full term infants: a longitudinal study in the first year

This longitudinal study examined dyadic and triadic skills in 26 preterm and 31 full term infants at 3, 6 and 9 months of age. In dyadic interaction, infants engaged with a stranger in face-to-face play interrupted by a still-face episode. In triadic interaction, infants interacted with the adult stranger as she coordinated gaze between the infant and object. Both groups were sensitive for non-contingency in both dyadic and triadic interactions. There were significant group and developmental differences for dyadic and triadic competencies. Compared to full term infants, preterms made less positive elicits during the still-face at 6 months and followed gaze less at 9 months of age. Six-month dyadic skills and 9-month triadic competencies were positively related in preterm and full term infants.     

What are you looking at? Infants’ neural processing of an adult's object‐directed eye gaze

Previous research suggests that by 4 months of age infants use the eye gaze of adults to guide their attention and facilitate processing of environmental information. Here we address the question of how infants process the relation between another person and an external object. We applied an ERP paradigm to investigate the neural processes underlying the perception of the direction of an adult's eye gaze in 4-month-old infants. Infants showed differential processing of an adult's eye gaze, which was directed at a simultaneously presented object compared to non-object-directed eye gaze. This distinction was evident in two ERP components: The Negative component, reflecting attentional processes, and the positive slow wave, which is involved in memory encoding. The implications of these findings for the development of joint attention and related social cognitive functions are discussed.     

Mother versus stranger: a triadic situation of imitation at the end of the first year of life

This study presents two experiments investigating 8‐ and 12‐month‐old infants' imitative behaviour. Seventy‐two 8‐month‐olds and seventy‐two 12‐month‐olds were observed in a triadic situation which included their mother and a stranger. Depending on the condition, either the mother or the stranger acted as the demonstrator and either stayed close or withdrew after the demonstration, during the response period. In addition to imitative acts, visual exploration and smiles addressed, respectively, to each partner were computed. Results showed that at both ages, neither the familiarity nor the position of the partner has an effect on the number of target gestures that are imitated. At 12 months, infants looked and smiled more at the stranger when he demonstrated target actions but no difference was found when the mother acted as demonstrator. Moreover, 12‐month‐old infants looked more at the demonstrating partner immediately after their first imitation. At 8 months, infants paid more attention to the stranger in all conditions except when the mother performed the target actions and moved away, a pattern that suggests a referencing to the mother. Results from the gaze and smile variables suggest that with age different motivations (social contact, exploration of objects) induce imitation. Copyright © 2003 John Wiley & Sons, Ltd.     

The development of gaze following and its relation to language

We examined the ontogeny of gaze following by testing infants at 9, 10 and 11 months of age. Infants (N = 96) watched as an adult turned her head toward a target with either open or closed eyes. The 10- and 11-month-olds followed adult turns significantly more often in the open-eyes than the closed-eyes condition, but the 9-month-olds did not respond differentially. Although 9-month-olds may view others as 'body orienters', older infants begin to register whether others are 'visually connected' to the external world and, hence, understand adult looking in a new way. Results also showed a strong positive correlation between gaze-following behavior at 10-11 months and subsequent language scores at 18 months. Implications for social cognition are discussed in light of the developmental shift in gaze following between 9 and 11 months of age.     

People and objects affect the quality of vocalizations in infants with down syndrome

The vocalizations of eight infants with Down syndrome were recorded longitudinally in relation to different social and non-social contexts. The infants were observed biweekly from 8 to 24 weeks and monthly up to 40 weeks. At each visit the infants were presented with their mother, a female stranger, and a rattle puppet, each alternately active and passive. Each condition lasted 60 sec. The results showed that by 4 months of age, the infants produced different types of vocal sounds in relation to environmental contexts. They produced significantly more melodic (speechlike) sounds, vocalic (non-speechlike) sounds, and emotional (crying, laughing and fussing) sounds when facing people than objects. By 6 months of age, these utterances began to be distinguished between mother and female stranger and active and passive adults. However, within the communicative context the overall amount of vocalic (non-speechlike) sounds produced was larger than the amount of melodic (speechlike) sounds. It is suggested that this low output of melodic sounds in the overall vocal production of these infants may adversely affect the development of more appropriate vocal behaviour.     

The control of social attention from 1 to 4 months

The control of social attention during early infancy was investigated in two studies. In both studies, an adult turned towards one of two targets within the infant's immediate visual field. We tested: (a) whether infants were able to follow the direction of the adult's head turn; and (b) whether following a head turn was accompanied by further gaze shifts between experimenter and target. In the first study, 1‐month‐olds did not demonstrate attention following at the group level. In addition, those infants who turned towards the same target remained fixed on it and did not shift attention again. In Study 2, we tested infants longitudinally at 2–4 months. At the group level, infants followed the adult's head turn at 3 and 4 months but not at 2 months. Those infants who turned towards the same target at 3 and 4 months also shifted gaze back and forth between experimenter and target. By 3 months, infants seem able to capitalize on the social environment to disengage and distribute attention more flexibly. The results support the claim that the control of social attention begins in early infancy, and are consistent with the hypothesis that following the attention of other people is dependent on the development of disengagement skills.     

The development of responses to people and a toy in infants with down syndrome

The behavior of eight infants with Down syndrome was observed biweekly from 8 to 24 weeks and monthly up to 48 weeks. At each visit the infants were presented with their mother, a female stranger, and a rattle puppet that were alternately active and passive. Each condition lasted 60 s. The results showed that by 4 months of age the infants began to differentiate, in the proportion of time they looked, smiled, and vocalized, between people and the toy. They did not discriminate, however, between mother and female stranger and between the active and passive adults until the second half of the first year. In particular, whereas normal infants usually show distress toward passive or “still-face” adults, the infants in this study continued to vocalize, at times even with smiling faces. The implications of these atypical aspects of the social development of infants with Down syndrome for their subsequent nonverbal communicative development are discussed.     

Gaze aversion during social interaction in preterm infants: a function of attention skills?

Preterm infants avert their gaze more often and for longer periods in early social interactions compared to full term infants. In previous studies this finding is interpreted as being a function of the higher degree of parental stimulation that is often found in parents of preterm children. The current study explores an additional hypothesis. Since the development of general visual attention abilities is found to be less optimal in preterm children, it is possible that less optimal maturation of attention abilities partially explains the elevated gaze aversion in a social context. Therefore, the current study investigated the association between gaze aversion in a social context and the ability to disengage and shift visual attention in a non-social context in 20 preterm and 42 full term infants aged 4 and 6 months. Results confirm that preterm infants are slower to shift their attention in a non-social context and that they avert their gaze more often in a social context compared to full term children. Furthermore, more frequent gaze aversion during social interaction at 6 months was related to longer disengagement and the shifting of attention at 4 and 6 months, but only within the preterm group. The results suggest that attention maturation is less optimal in preterm children; this can be observed in a non-social as well as a social context. Less attention maturation in preterm children can negatively influence the amount of time they can stay actively involved in social interaction.     

Enhanced gaze‐following behavior in Deaf infants of Deaf parents

Gaze following plays a role in parent–infant communication and is a key mechanism by which infants acquire information about the world from social input. Gaze following in Deaf infants has been understudied. Twelve Deaf infants of Deaf parents (DoD) who had native exposure to American Sign Language (ASL) were gender‐matched and age‐matched (±7 days) to 60 spoken‐language hearing control infants. Results showed that the DoD infants had significantly higher gaze‐following scores than the hearing infants. We hypothesize that in the absence of auditory input, and with support from ASL‐fluent Deaf parents, infants become attuned to visual‐communicative signals from other people, which engenders increased gaze following. These findings underscore the need to revise the ‘deficit model’ of deafness. Deaf infants immersed in natural sign language from birth are better at understanding the signals and identifying the referential meaning of adults’ gaze behavior compared to hearing infants not exposed to sign language. Broader implications for theories of social‐cognitive development are discussed. A video abstract of this article can be viewed at https://youtu.be/QXCDK_CUmAI     

The Cross-Modal Coordination of Interpersonal Timing: Six-Week-Olds Infants' Gaze with Adults' Vocal Behavior

The purpose of this study was to examine the hypothesis that 6-week-old infants are capable of coordinated interpersonal timing within social interactions. Coordinated interpersonal timing refers to changes in the timing of one individual's behavior as a function of the timing of another individual's behavior. Each of 45, first-born 6-week-old infants interacted with his or her mother and a stranger for a total of 14 minutes. The interactions were videotaped and coded for the gaze behavior of the infants and the vocal behavior of the mothers and strangers. Time-series regression analyses were used to assess the extent to which the timing of each of the infants' gazes was coordinated with the timing of the adults' vocal behavior. The results revealed that (a) coordinated timing occurs between infants and their mothers and between infants and strangers as early as when infants are 6 weeks old, and (b) strangers coordinated the timing of their pauses with the infants to a greater extent than did mothers. The findings are discussed in terms of the role of temporal sensitivity in social interaction.     

Cross-sectional study of coordination between infants' gaze and vocalizations towards their mothers

The study aimed at providing more precise information about infants' capacity to coordinate their vocalizations with gaze towards their mothers. A total of 32 infants were observed, four boys and four girls in each of four age groups (4, 6, 8 and 10 months), in an observational setting aimed at minimizing infants' casual looks to their mothers. Videotapes of mother-infant-toy interactions were coded separately for infants' vocalizations and gaze towards their mothers, and the difference between observed and expected cooccurrence of these two communicative behaviours was evaluated by transfromation into z-scores. Results indicate that only at 10 months of age do infants develop the ability to coordinate vocalizations and gazes towards mother. Moreover, more competent subjects show temporal relationships between gaze and vocalizations different from those observed in less competent subjects.     

Origins of the human pointing gesture: a training study

Despite its importance in the development of children’s skills of social cognition and communication, very little is known about the ontogenetic origins of the pointing gesture. We report a training study in which mothers gave children one month of extra daily experience with pointing as compared with a control group who had extra experience with musical activities. One hundred and two infants of 9, 10, or 11 months of age were seen at the beginning, middle, and end of this one‐month period and tested for declarative pointing and gaze following. Infants’ability to point with the index finger at the end of the study was not affected by the training but was instead predicted by infants’ prior ability to follow the gaze direction of an adult. The frequency with which infants pointed indexically was also affected by infant gaze following ability and, in addition, by maternal pointing frequency in free play, but not by training. In contrast, infants’ ability to monitor their partner’s gaze when pointing, and the frequency with which they did so, was affected by both training and maternal pointing frequency in free play. These results suggest that prior social cognitive advances, rather than adult socialization of pointing per se, determine the developmental onset of indexical pointing, but socialization processes such as imitation and adult shaping subsequently affect both infants’ ability to monitor their interlocutor’s gaze while they point and how frequently infants choose to point.     

Additive effects of social and non‐social attention during infancy relate to later autism spectrum disorder

Emerging findings from studies with infants at familial high risk for autism spectrum disorder (ASD), owing to an older sibling with a diagnosis, suggest that those who go on to develop ASD show early impairments in the processing of stimuli with both social and non‐social content. Although ASD is defined by social‐communication impairments and restricted and repetitive behaviours, the majority of cognitive theories of ASD posit a single underlying factor, which over development has secondary effects across domains. This is the first high‐risk study to statistically differentiate theoretical models of the development of ASD in high‐risk siblings using multiple risk factors. We examined the prediction of ASD outcome by attention to social and non‐social stimuli: gaze following and attentional disengagement assessed at 13 months in low‐risk controls and high‐risk ASD infants (who were subsequently diagnosed with ASD at 3 years). When included in the same regression model, these 13‐month measures independently predicted ASD outcome at 3 years of age. The data were best described by an additive model, suggesting that non‐social attention, disengagement, and social attention as evidenced by gaze following, have a cumulative impact on ASD risk. These data argue against cognitive theories of ASD which propose that a single underlying factor has cascading effects across early development leading to an ASD outcome, and support multiple impairment models of ASD that are more consistent with recent genetic and neurobiological evidence.     

Emerging sensitivity to the timing and structure of protoconversation in early infancy.

Thirty-six 2-, 4-, and 6-month-old infants were videotaped while interacting with a female adult stranger engaging in either organized or disorganized 1-min peekaboo games. Two-month-old infants gazed and smiled equally at the stranger, regardless of the relative organization of the peekaboo game. In contrast, 4- and 6-month-old infants smiled significantly more and gazed significantly less in the organized peekaboo condition than in the disorganized peekaboo condition. These results suggest that from a diffuse sensitivity to the presence of a social partner, infants by 4 months develop a new sensitivity to the narrative envelope of protoconversation, in particular the timing and the structure of social exchanges scaffolded by adults. These observations are interpreted as evidence of developing social expectations in the first 6 months of life. This early development is viewed as announcing and preparing the communicative competence that blossoms by the end of the 1st year.     

The development of the still-face effect: Mothers do matter

The Face-to-Face Still-Face paradigm (FFSF) has been used to investigate how infants react to stressful events. However, there is little developmental data on the FFSF effect, and whether it connects to a specific relationship (e.g., to a mother versus a stranger). This prospective longitudinal study aims to evaluate developmental changes in infant reaction to the FFSF presented by the mother or a stranger at 2, 4, 6, and 8 months of age (n = 39). Results show that infant negativity was expressed less in relation to a stranger, the identity effect. Results further suggest that from 6 to 8 months of age, stranger induced protest flattens out; whereas mother induced protest decreases. The results are discussed in relation to different theories regarding infant responsiveness.     

Infant–mother social referencing interactions: Description and antecedents in maternal sensitivity and infant irritability

The purpose of the study was to describe naturally occurring infant and maternal behaviours in terms of social referencing in a stranger wariness situation, and to explore antecedents to such behaviouts in early maternal sensitivity and infant irritability. One hundred and ten 10-months-old infants and their mothers were videotaped. Infant social referencing behaviour was defined as puzzled looks directed at mother's face after the infant had discovered the stranger. Almost half of the infants looked with a puzzled expression at their mothers immediately after discovering the stranger, and a majority of the mothers sent a positive message back to the infants. Twenty per cent of the infants never looked at their mothers and 20% of the mothers did not respond when their infants turned to them. Infants whose mothers had responded positively to the referencing look showed positive responses to the stranger to a higher degree than infants who did not reference or those who were not responded to. Antecedents to infant and mother interactive behaviours were sought in maternal sensitivity (general sensitivity, physical contact, responsiveness, intrusiveness, response to distress, and effectiveness in comforting) and in infant irritability as observed when the infants were 4 months old. It was found that infants who did not reference their mothers for information at 10 months had experienced less sensitive mothering 6 months earlier and had also shown more irritability.     

Neonatal imitation, gaze aversion, and mother-infant interaction

A relationship between elicited imitation in neonates and social interaction has been proposed by several investigators. The present work examines if such a relationship can be found when studying neonatal imitation, gaze aversion, and mother-infant interaction. Thirty-two infants were observed at 2 to 3 days, 3 weeks, and 3 months of age. Imitation of tongue protrusion and mouth opening was assessed in all three observations. In addition, a face-to-face interaction between mother and child was included when the child reached 3 months of age. The most striking result was a negative relationship between the infants' brief gaze aversion observed at 3 months of age while interacting with their mothers and the infants' imitative reactions at 2 to 3 days, 3 weeks, and 3 months of age. Behaviorally, these patterns indicate that high-imitating infants tend to display fewer episodes of brief gaze aversion when interacting with their mothers.     

The Animate-Inanimate Distinction in Infancy: Developing Sensitivity to Constraints on Human Actions

Infants aged 4 and 6 months were presented with events in which a person acted so as to set another person, or an inanimate object, in motion. In one condition, the actor spoke to the person (natural) or inanimate object (unnatural); in the other condition, the actor grasped and manipulated the person (unnatural) or object (natural). Six-month-old infants looked reliably longer at the natural actions than at the unnatural actions. A follow-up experiment revealed that their preference depended on the naturalness of the human actions themselves, not on the features or motions of the person or object that was acted upon. Looking preferences at 4 months were equivocal, consistent with the thesis that sensitivity to the natural actions develops over the first 6 months of age. We discuss these findings in relation to the development of social understanding, social gaze, and visual exploration.     

Selective attention to a talker's mouth in infancy: role of audiovisual temporal synchrony and linguistic experience

Previous studies have found that infants shift their attention from the eyes to the mouth of a talker when they enter the canonical babbling phase after 6 months of age. Here, we investigated whether this increased attentional focus on the mouth is mediated by audio‐visual synchrony and linguistic experience. To do so, we tracked eye gaze in 4‐, 6‐, 8‐, 10‐, and 12‐month‐old infants while they were exposed either to desynchronized native or desynchronized non‐native audiovisual fluent speech. Results indicated that, regardless of language, desynchronization disrupted the usual pattern of relative attention to the eyes and mouth found in response to synchronized speech at 10 months but not at any other age. These findings show that audio‐visual synchrony mediates selective attention to a talker's mouth just prior to the emergence of initial language expertise and that it declines in importance once infants become native‐language experts.