Emergence of Joint Attention: Relationships Between Gaze Following,Social Referencing,Imitation, and Naming in Infancy

The authors investigated the extent to which the joint-attention behaviors of gaze following, social referencing, and object-directed imitation were related to each other and to infants' vocabulary development in a sample of 60 infants between the ages of 8 and 14 months. Joint-attention skills and vocabulary development were assessed in a laboratory setting. Split-half reliability analyses on the joint-attention measures indicated that the tasks reliably assessed infants' capabilities. In the main analysis, no significant correlations were found among the joint-attention behaviors except for a significant relationship between gaze following and the number of names in infants' productive vocabularies. The overall pattern of results did not replicate results of previous studies (e.g., M. Carpenter, K. Nagell, & M. Tomasello, 1998) that found relationships between various emerging joint-attention behaviors.     

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.     

Driven from distraction: how infants respond to parents' attempts to elicit and re-direct their attention

This experiment examined how parents' verbal and non-verbal behavioral cues cause infants to shift and share attention within environments where many objects compete for infants' attention. Fifteen- and 21-month-old infants played with toys while their parent periodically shifted attention to a distal object within a larger array. Parents' attention-shifts were indicated by a change in direction of gaze, a pointing gesture, and/or verbalizations. Verbalizations were either attention-eliciting or attention-directing. In some trials parents covered their eyes to occlude line-of-gaze. Both ages seldom followed simple gaze shifts, but frequently followed gaze with-points or gaze-with-directing verbalizations. Attention-eliciting verbalizations increased infants' looks to the parent. Gaze occlusion reduced infants' responses to directing verbalizations. Responses to eliciting verbalizations increased with age. Infant receptive vocabulary did not predict attention-sharing, even when parents named objects (i.e., directing verbalizations). Implications for development of attention-sharing, language and understanding of visual attention are discussed.     

Gaze following as a function of affective expression in 3-, 6- and 9-month-old infants

The influence of affective expression on gaze following was investigated in 3-, 6- and 9-month-old infants. Gaze following became more robust at the older ages. There was no strong evidence that infants' gaze following activity was differentially influenced by the adult's affective expression, but rather for a developmental difference in emotion processing.     

Infants' early ability to segment the conversational speech signal predicts later language development: a retrospective analysis

Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2 assessed linguistic and cognitive skills at 4-6 years of age for children who had participated in segmentation studies as infants. Children who had been able to segment words from fluent speech scored higher on language measures, but not general IQ, as preschoolers. Results suggest that speech segmentation ability is an important prerequisite for successful language development, and they offer potential for developing measures to detect language impairment at an earlier age.     

Adult's Eyes Trigger Shifts of Visual Attention in Human Infants

Two experiments examined whether infants shift their visual attention in the direction toward which an adult's eyes turn. A computerized modification of previous joint-attention paradigms revealed that infants as young as 3 months attend in the same direction as the eyes of a digitized adult face. This attention shift was indicated by the latency and direction of their orienting to peripheral probes presented after the face was extinguished. A second experiment found a similar influence of direction of perceived gaze, but also that less peripheral orienting occurred if the central face remained visible during presentation of the probe. This may explain why attention shifts triggered by gaze perception have been difficult to observe in infants using previous naturalistic procedures. Our new method reveals both that direction of perceived gaze can be discriminated by young infants and that this perception triggers corresponding shifts of their own attention.     

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.     

Perturbation of Japanese mother-infant habitual interactions in the double video paradigm and relationship to maternal playfulness

Double video paradigm (DVP) studies have found contradictory evidence regarding the young infants' ability to discriminate their mother's 'replay' image from 'live'. This study examined the hypothesis that 4-month-old infants whose mothers showed high-levels-of-playful-behavior are more likely to discriminate social contingency in the DVP. We also examined the relationships between the infants' DVP behaviors and mothers' free-play behaviors at home with their 3-month-old infants. The results supported our hypothesis. Further, when the mothers' behaviors were reduced to playful companion (PC) and sensitive support (SS) by a principal component analysis, the level of PC was closely related to the infants' detection of social contingency, but SS was not. The different functions of mothers' 'playfulness' and 'sensitivity' in communication with their infants are discussed.     

Gaze control in putting.

The gaze of low and higher handicap golfers was assessed while they performed consecutive putts from 3 m, wearing an eye-movement helmet that permitted normal mobility. MANOVA (count and duration), with univariate follow-up, revealed significant differences in gaze between five low (LH, 0-8) and seven higher handicap golfers (HH, 10-16). The LH (ie more highly skilled) golfers were found to use a variable form of gaze control in which longer fixation durations on the ball and target were observed, and there were fewer fixations on the club and surface, with more express saccades and quicker saccades between gaze locations. The HH golfers, in contrast, allocated the same mean durations to each gaze (about 1 s), independent of type of control (fixation, saccade, or tracking) or location (ball, club, target, or surface). In comparing hits to misses, there was an increased probability of hits if the golfers used express saccades to the club during preparation, and a steady fixation on the ball during the backswing/foreswing of the club, as well as a steady fixation on the surface during contact. These results suggest that with the acquisition of the putting skill, there are changes in gaze control, characterized by economy in the number of gaze shifts, the development of priority to specific gaze locations, and economy in the allocation of time between preferred gaze locations. In the discussion two reasons are proposed that may partially explain the results found here, as well as help further our understanding of the role of gaze in targetting skills.     

The effect of positive emotion on infants' gaze shift

Infants often voluntarily glance at their social partner during their toy play, disengaging their gaze from a toy and selecting a caregiver as their new looking target. This study posed two research questions: Do positive emotions disengage infants' gaze from their point of fixation, and do positive emotions facilitate the selection of the caregiver as their next looking target? The rate of gaze shifts was calculated for neutral and positive emotional states during their toy play. Across all ages, infants exhibited more disengagement from their point of fixation in the positive state than in the neutral one. However, 6- and 9-month-old infants revealed no difference in selecting a caregiver or a physical object as their next looking target in the positive state, but 12-month-olds increased gazing at caregivers in the positive state. These results were discussed with regard to the role of positive emotions on the development of infants' initiating joint attention.     

婴儿共同注意能力的发展

本研究采用严格的实验室测验法,从年龄趋势、学习能力、性别差异三方面考察了8～11个月婴儿共同注意能力的发展。结果表明：1）婴儿的共同注意力在8～11个月间逐步提高,9个月左右出现显著的发展性变化,但1岁以前,该能力的发展水平都较低;2）就共同注意而言,婴儿具有从练习经验中学习的可能性,且学习能力存在年龄差异,8个月的婴儿基本不能从练习中受益,而8个月以上的其他三组婴儿在练习后共同注意水平都有不同程度的提高;3）总体而言,女婴共同注意能力的发展水平显著地高于男婴。     

Action production influences 12-month-old infants' attention to others' actions

Recent work implicates a link between action control systems and action understanding. In this study, we investigated the role of the motor system in the development of visual anticipation of others' actions. Twelve-month-olds engaged in behavioral and observation tasks. Containment activity, infants' spontaneous engagement in producing containment actions; and gaze latency, how quickly they shifted gaze to the goal object of another's containment actions, were measured. Findings revealed a positive relationship: infants who received the behavior task first evidenced a strong correlation between their own actions and their subsequent gaze latency of another's actions. Learning over the course of trials was not evident. These findings demonstrate a direct influence of the motor system on online visual attention to others' actions early in development.     

Audience gaze while appreciating a multipart musical performance

Visual information has been observed to be crucial for audience members during musical performances. The present study used an eye tracker to investigate audience members’ gazes while appreciating an audiovisual musical ensemble performance, based on evidence of the dominance of musical part in auditory attention when listening to multipart music that contains different melody lines and the joint-attention theory of gaze. We presented singing performances, by a female duo. The main findings were as follows: (1) the melody part (soprano) attracted more visual attention than the accompaniment part (alto) throughout the piece, (2) joint attention emerged when the singers shifted their gazes toward their co-performer, suggesting that inter-performer gazing interactions that play a spotlight role mediated performer-audience visual interaction, and (3) musical part (melody or accompaniment) strongly influenced the total duration of gazes among audiences, while the spotlight effect of gaze was limited to just after the singers’ gaze shifts.     

Foetal testosterone and vocabulary size in 18- and 24-month-old infants

Amniotic fluid, obtained from 87 pregnant women for routine amniocentesis, was analysed for foetal testosterone (FT) level. Their infants (40 girls and 47 boys) were followed up 18 and 24 months after birth and their vocabulary size was assessed. Girls were found to have a significantly larger vocabulary than boys at both ages. This replicates previous findings of a female advantage in language ability, but reveals this sex difference at the earliest point of development. Additionally, FT was an inverse predictor of vocabulary size when data from both sexes was examined together, but not within sex. The lack of a significant correlation between FT and vocabulary within each sex may reflect the relatively small sample size. However, the significant correlation between FT and vocabulary when the sexes were combined suggests FT might be involved in shaping the neural mechanisms underlying communicative development.     

Socio-demographic determinants of infant neurodevelopment at 18 months of age: Mother-Child Cohort (Rhea Study) in Crete, Greece

Studies on determinants affecting child development are still limited in Greece. The aim of the present study was to describe the socio-demographic characteristics associated with neurodevelopment in infants aged 18 months in the Mother-Child Cohort (Rhea Study) in Crete, Greece. A total of 599 (72.9%) mothers agreed to participate in the neurodevelopment protocol and 612 infants (586 singletons and 26 twins) were assessed by means of the Bayley Scales of Infant and Toddler Development (3rd edition). The present analysis includes 605 infants. Multivariable linear regression models were implemented to examine the associations between the Bayley-III standardised scores and different parental and infant characteristics, also adjusting for quality of assessment. Girls were found to have better neurodevelopmental outcomes in cognitive, receptive and expressive communication, fine motor and social-emotional development. Maternal higher education was positively associated to almost all aspects of infant neurodevelopment assessed. Increasing number of older siblings was negatively associated with cognitive development, communication skills and gross motor development. Our results, also, suggest a positive effect of maternal employment on infants' receptive and expressive communication, and gross motor scores. The results of the present study suggest that in the population on Crete social and environmental factors contributed more to infants' neurodevelopment at 18 months than biological factors.     

Infant responding to joint attention, executive processes, and self-regulation in preschool children

Infant joint attention is related to behavioral and social outcomes, as well as language in childhood. Recent research and theory suggests that the relations between joint attention and social-behavioral outcomes may reflect the role of executive self-regulatory processes in the development of joint attention. To test this hypothesis two studies were conducted. The first, cross-sectional study examined the development of responding to joint attention (RJA) skill in terms of increasing executive efficiency of responding between 9 and 18 months of age. The results indicated that development of RJA was characterized by a decreased latency to shift attention in following another person's gaze and head turn, as well as an increase in the proportion of correct RJA responses exhibited by older infants. The second study examined the longitudinal relations between 12-month measures of responding to joint attention and 36-month attention regulation in a delay of gratification task. The results indicated that responding to joint attention at 12-months was significantly related to children's use of three types of self-regulation behaviors while waiting for a snack reward at 36 months of age. These observations are discussed in light of a developmental theory of attention regulation and joint attention in infancy.     

Maternal regulation of infant reactivity from 2 to 6 months

Previous research has investigated the effect of maternal soothing behaviors on reducing infant reactivity but not the differential effects of specific maternal behaviors on infant stress responses. The present study investigated maternal regulation of 2- and 6-month-olds' responses to an inoculation and found a significant decline with age in both the intensity and duration of infants' crying. Maternal affection and touching decreased from 2 to 6 months, whereas maternal vocalizing and distraction behaviors increased. At both ages, the combination of maternal holding/rocking and vocalizing was associated with decreases in all levels of infant reactivity. Neither strategy alone, however, was found to be effective. Feeding/ pacifying behaviors were effective only when initial distress was at a low or moderate level, which suggests that the effectiveness of maternal regulatory behaviors may depend on the intensity of infants' crying.     

Self-experience as a mechanism for learning about others: a training study in social cognition

Using a gaze-following task, the authors assessed whether self-experience with the view-obstructing properties of blindfolds influenced infants' understanding of this effect in others. In Experiment 1, 12-month-olds provided with blindfold self-experience behaved as though they understood that a person wearing a blindfold cannot see. When a blindfolded adult turned to face an object, these infants gaze followed significantly less than control infants who had either (a) seen and felt the blindfold but whose view had not been obstructed by it or (b) experienced a windowed blindfold through which they could see. In Experiment 2, 18-month-olds experienced either (a) a trick blindfold that looked opaque but could be seen through, (b) an opaque blindfold, or (c) baseline familiarization. Infants receiving trick-blindfold experience now followed a blindfolded adult's gaze significantly more than controls. The authors propose 3 mechanisms underlying infants' capacity to use self-experience as a framework for understanding the visual perception of others.     

Infants' responses to arm restraint at 2 and 6 months: a longitudinal study

This study examined the continuity, stability, and change of infants' responses to a frustrating event (i.e., arm restraint) between 2 and 6 months in terms of both negative reactivity and its regulation. Fifty-two healthy, full-term infants and their mothers participated in an arm restraint procedure. Infant behaviors were observed and coded at 3-s intervals. The results showed that infants' reactivity to frustration and their ability to regulate such reactivity significantly changed in level over time. Individual differences in frustration reactivity were stable across the two ages; two regulatory behaviors (i.e., orientation to mother and avoidance) could be observed in the same percentage of babies at both 2 and 6 months. At 6 months, several significant associations between frustration reactivity and infant regulatory behaviors emerged. These findings suggest that the arm restraint procedure may be usefully employed to study individual differences in infants as young as 2 months of age.     

Gaze behavior and affect at 6 months: predicting clinical outcomes and language development in typically developing infants and infants at risk for autism

This paper presents follow‐up longitudinal data to research that previously suggested the possibility of abnormal gaze behavior marked by decreased eye contact in a subgroup of 6‐month‐old infants at risk for autism ( Merin, Young, Ozonoff & Rogers, 2007 ). Using eye‐tracking data and behavioral data recorded during a live mother–infant interaction involving the still‐face procedure, the predictive utility of gaze behavior and affective behaviors at 6 months was examined using diagnostic outcome data obtained longitudinally over the following 18 months. Results revealed that none of the infants previously identified as showing lower rates of eye contact had any signs of autism at outcome. In contrast, three infants who were diagnosed with autism demonstrated consistent gaze to the eye region and typical affective responses at 6 months. Individual differences in face scanning and affective responsivity during the live interaction were not related to any continuous measures of symptom frequency or symptom severity. In contrast, results of growth curve models for language development revealed significant relationships between face scanning and expressive language. Greater amounts of fixation to the mother's mouth during live interaction predicted higher levels of expressive language at outcome and greater rates of growth. These findings suggest that although gaze behavior at 6 months may not provide early markers for autism as initially conceived, gaze to the mouth in particular may be useful in predicting individual differences in language development.