Marked referential communicative behaviours,but no differentiation of the “knowledge state” of humans in untrained pet dogs versus 1-year-old infants

The study examines whether untrained dogs and infants take their caregiver’s visual experience into account when communicating with them. Fifteen adult dogs and 15 one-year-old infants were brought into play with their caregivers with one of their own toys. The caregiver gave the toy to the experimenter, who, in different conditions, placed it either above or under one of two containers, with both the infant or dog and the caregiver witnessing the positioning; in a third condition, the caregiver left the room before the toy was placed under one of the two containers and later returned. Afterwards, for each condition, the caregiver asked the participant to indicate the location of the toy. Neither dogs nor infants—untrained to the use of the partner’s knowledge state—showed much difference of behaviour between the three conditions. However, dogs showed more persistence for most behaviours (gaze at the owner, gaze at the toy and gaze alternation) and conditions, suggesting that the situation made more demands on dogs’ communicative behaviours than on those of infants. When all deictic behaviours of infants (arm points towards the toy and gaze at the toy) were taken into account, dogs and infants did not differ. Phylogeny, early experience and ontogeny may all play a role in the ways that both species communicate with adult humans.     

Gaze direction and maternal pitch in surprise-eliciting situations

The purpose of this study was to test the hypothesis that not only do babies use emotional signals from adults in order to relate emotions to specific situations (e.g., Campos & Stenberg, 1981) but also that mothers seek out emotional information from their infants ( Emde, 1992). Three groups of mothers and their infants, 3, 5 and 9 months old were video- and audio-taped, while playing in their homes with a soft toy and a remote-control Jack-in-the-box. During surprise-eliciting play with the Jack-in-the-box, maternal and infant gaze direction and their emotional expressions of surprise, pleasure, fear and neutral expressions were coded in three regions of the face. In addition, the mean fundamental frequency of maternal surprise-vocalisations was analysed. Maternal exclamations of surprise were compared with similar utterances of these mothers while playing with a soft toy as a baseline. During the surprise event, maternal and infant gaze directions as well as infant age were analysed in relation to maternal pitch. Results are discussed in terms of maternal use of the pitch of her voice to mark surprising situations, depending on the gaze-direction of the infant.     

One-year-olds comprehend the communicative intentions behind gestures in a hiding game

This study explored infants' ability to infer communicative intent as expressed in non-linguistic gestures. Sixty children aged 14, 18 and 24 months participated. In the context of a hiding game, an adult indicated for the child the location of a hidden toy by giving a communicative cue: either pointing or ostensive gazing toward the container containing the toy. To succeed in this task children had to do more than just follow the point or gaze to the target container. They also had to infer that the adult's behaviour was relevant to the situation at hand - she wanted to inform them that the toy was inside the container toward which she gestured. Children at all three ages successfully used both types of cues. We conclude that infants as young as 14 months of age can, in some situations, interpret an adult behaviour as a relevant communicative act done for them.     

Looking happy: the experimental manipulation of a positive visual attention bias

Individuals with a positive visual attention bias may use their gaze to regulate their emotions while under stress. The current study experimentally trained differential biases in participants' (N = 55) attention toward positive or neutral information. In each training trial, one positive and one neutral word were presented and then a visual target appeared consistently in the location of the positive or neutral words. Participants were instructed to make a simple perceptual discrimination response to the target. Immediately before and after attentional training, participants were exposed to a stress task consisting of viewing a series of extremely negative images while having their eyes tracked. Visual fixation time to negative images, assessed with an eye tracker, served as an indicator of using gaze to successfully regulate emotion. Those participants experimentally trained to selectively attend to affectively positive information looked significantly less at the negative images in the visual stress task following the attentional training, thus demonstrating a learned aversion to negative stimuli. Participants trained toward neutral information did not show this biased gaze pattern.     

Drawn towards what others seem to like: Implicit preference for objects and people looked at with a duchenne smile

People tend to like objects that are looked at by others, especially if the person looking at the object expresses a positive emotion. But not all positive emotions are equal. We investigated the effect of third party gazing while expressing subtle positive emotions on perceivers’ subsequent preferences and evaluations of objects and people. In two studies participants saw faces looking at target objects and people either with a Duchenne, a non-Duchenne smile, or a neural expression. Participants first indicated gaze direction and later reported intuitive target preference and evaluated the targets. Results show a preference for target stimuli that were smiled at with a Duchenne smile as opposed to when they were looked at with a non-Duchenne smile or a neutral expression. More explicit evaluations of the target stimuli were not affected by the type of facial expression.     

Fearful faces modulate looking duration and attention disengagement in 7-month-old infants

The present study investigated whether facial expressions modulate visual attention in 7-month-old infants. First, infants' looking duration to individually presented fearful, happy, and novel facial expressions was compared to looking duration to a control stimulus (scrambled face). The face with a novel expression was included to examine the hypothesis that the earlier findings of greater allocation of attention to fearful as compared to happy faces could be due to the novelty of fearful faces in infants' rearing environment. The infants looked longer at the fearful face than at the control stimulus, whereas no such difference was found between the other expressions and the control stimulus. Second, a gap/overlap paradigm was used to determine whether facial expressions affect the infants' ability to disengage their fixation from a centrally presented face and shift attention to a peripheral target. It was found that infants disengaged their fixation significantly less frequently from fearful faces than from control stimuli and happy faces. Novel facial expressions did not have a similar effect on attention disengagement. Thus, it seems that adult-like modulation of the disengagement of attention by threat-related stimuli can be observed early in life, and that the influence of emotionally salient (fearful) faces on visual attention is not simply attributable to the novelty of these expressions in infants' rearing environment.     

The development of emotional face and eye gaze processing

Recent research has demonstrated that infants' attention towards novel objects is affected by an adult's emotional expression and eye gaze toward the object. The current event-related potential (ERP) study investigated how infants at 3, 6, and 9 months of age process fearful compared to neutral faces looking toward objects or averting gaze away from objects. Furthermore, we examined how the processing of novel objects is affected by gaze direction and emotional expression. We hypothesized that an adult's fearful expression should be particularly salient when it is directed toward a referent in the environment. Furthermore, responses to objects should be increased if the face previously expressed fear toward the object. Three-month-olds did not show differential neural responses to fearful vs. neutral faces regardless of gaze direction. Six-month-olds showed an enhanced negative central (Nc) component for fearful relative to neutral faces looking toward objects, but not when eye gaze was averted away from the objects. Furthermore, 6-month-olds showed an enhanced Nc for objects that had been gaze-cued by a fearful compared to a neutral face. Nine-month-olds showed an enhanced Nc for fearful relative to neutral faces in both eye gaze conditions and showed an enhanced Nc for objects that had been gaze-cued by a neutral face. The findings are discussed in the context of social cognitive and brain development.     

Association between Hyperemesis Gravidarum in pregnancy on postnatal ability of infants to attend to a play task with their mother

Research indicates a higher prevalence of attention deficits in children exposed to HG in utero compared to controls with some claiming that the deficit is due to prenatal effects of malnutrition in HG mothers and others that it is due to maternal mental health after birth. The current study examines the effect of hyperemesis gravidarum (HG) diagnosis during pregnancy on infant attention controlling for maternal stress, depression anxiety and attachment. Thirty-eight infants mean age 4 months were videotaped with their mothers (19 mothers with a hyperemesis diagnosis and 19 controls) during play with a soft toy and looking at a picture book. Infant attention was operationalized as gaze direction towards the play activity, mother, and ‘distracted’ (indicated by looking away from play or mother). Mothers completed stress, depression, anxiety, and attachment questionnaires. HG exposed infants attended for significantly less time during play with a book or soft toy compared to controls. Maternal stress, depression, anxiety, and attachment did not differ in HG mothers and controls. Infant ability to attend to the toy, book, mother or being distracted did not relate to maternal postnatal attachment, or mental health. These results suggest that the prenatal environment, especially exposure to HG might be associated with reduced infant attention abilities independent of maternal postnatal health.     

Toddlers’ Understanding of Peers’ Emotions

The second year of life sees dramatic developments in infants’ ability to understand emotions in adults alongside their growing interest in peers. In this study, the authors used a social-referencing paradigm to examine whether 12-, 18-, and 24-month-old children could use a peer's positive or negative emotion messages about toys to regulate their own behavior with the toys. They found that 12-month-olds decreased their play with toys toward which a peer had expressed either positive or negative emotion compared with play following a peer's neutral attention toward a toy. Also, 18-month-olds did not respond systematically, but 24-month-old children increased their toy play after watching a peer display negative affect toward the toy. Regardless of their age, children with siblings decreased their play with toys toward which they had seen a peer display fear, the typical social-referencing response. The authors discuss results in the context of developmental changes in social understanding and peer interaction over the second year of life.     

Manual exploration of objects is related to 7-month-old infants’ visual preference for real objects

The present study examined whether infants’ visual preferences for real objects and pictures are related to their manual object exploration skills. Fifty-nine 7-month-old infants were tested in a preferential looking task with a real object and its pictorial counterpart. All of the infants also participated in a manual object exploration task, in which they freely explored five toy blocks. Results revealed a significant positive relationship between infants’ haptic scan levels in the manual object exploration task and their gaze behavior in the preferential looking task: The higher infants’ haptic scan levels, the longer they looked at real objects compared to pictures. Our findings suggest that the specific exploratory action of haptically scanning an object is associated with infants’ visual preference for real objects over pictures.     

Dynamic emotional messages differentially affect 6-month-old infants’ attention to eyes and gaze cues

Infants often experience interactions in which caregivers use dynamic messages to convey their affective and communicative intent. These dynamic emotional messages may shape the development of emotion discrimination skills and shared attention by influencing infants’ attention to internal facial features and their responses to eye gaze cues. However, past research examining infants’ responses to emotional faces has predominantly focused on classic, stereotyped expressions (e.g., happy, sad, angry) that may not reflect the variability that infants experience in their daily interactions. The present study therefore examined forty-two 6-month-old infants’ attention to eyes vs. mouth and gaze cueing responses across multiple dynamic emotional messages that are common to infant-directed interactions. Overall, infants looked more to the eyes during messages with negative affect, but this increased attention to the eyes during these message conditions did not directly facilitate gaze cueing. Infants instead showed reliable gaze cueing only after messages with positive and neutral affect. We additionally observed gender differences in infants’ attention to internal face features and subsequent gaze cueing responses. Female infants spent more time looking at the eyes during the dynamic emotional messages and showed increased initial orienting and longer looking to gaze-cued objects following positive messages, whereas male infants showed these gaze cueing effects following neutral messages. These results suggest that variability in caregivers' communication can shape infants’ attention to and processing of emotion and gaze information.     

Infants of adolescent and adult mothers: two indices of socioemotional development

This study compared infant-mother attachment and mastery motivation in one-year-old babies born to adolescent and adult mothers. In the laboratory, the infants' mastery motivation was assessed in an experimenter-administered structured toy play session and infant-mother attachment was classified on the basis of the strange situation procedure. The results indicated that there were more, although not significantly so, securely attached infants among those born to adult than to adolescent mothers (70% as compared to 53%). The relatively low number of securely attached infants in the adolescent mother group may reflect the fact that in many cases the mothers were not the primary caretakers. Among the adolescents, the majority were living with their family of origin. Nevertheless, their infants' motivation to master the environment, assessed independently, compared favorably with that of the adult mother group. Infants of adolescent mothers were significantly more persistent than were those born to adult mothers, although they were affectively less positive during the toy play. It is suggested that the socioemotional development of infants born to adolescent mothers may be buffered by a network containing multiple caretakers. Finally, the relationship between attachment and mastery motivation was examined. The results showed that infants with an avoidant or secure attachment relationship were more persistent as well as competent than were ambivalent infants during free play.     

See and be seen: Infant–caregiver social looking during locomotor free play

Face‐to‐face interaction between infants and their caregivers is a mainstay of developmental research. However, common laboratory paradigms for studying dyadic interaction oversimplify the act of looking at the partner's face by seating infants and caregivers face to face in stationary positions. In less constrained conditions when both partners are freely mobile, infants and caregivers must move their heads and bodies to look at each other. We hypothesized that face looking and mutual gaze for each member of the dyad would decrease with increased motor costs of looking. To test this hypothesis, 12‐month‐old crawling and walking infants and their parents wore head‐mounted eye trackers to record eye movements of each member of the dyad during locomotor free play in a large toy‐filled playroom. Findings revealed that increased motor costs decreased face looking and mutual gaze: Each partner looked less at the other's face when their own posture or the other's posture required more motor effort to gain visual access to the other's face. Caregivers mirrored infants' posture by spending more time down on the ground when infants were prone, perhaps to facilitate face looking. Infants looked more at toys than at their caregiver's face, but caregivers looked at their infant's face and at toys in equal amounts. Furthermore, infants looked less at toys and faces compared to studies that used stationary tasks, suggesting that the attentional demands differ in an unconstrained locomotor task. Taken together, findings indicate that ever‐changing motor constraints affect real‐life social looking.     

Infants' representations of three-dimensional occluded objects

Infants' ability to represent objects has received significant attention from the developmental research community. With the advent of eye-tracking technology, detailed analysis of infants' looking patterns during object occlusion have revealed much about the nature of infants' representations. The current study continues this research by analyzing infants' looking patterns in a novel manner and by comparing infants' looking at a simple display in which a single three-dimensional (3D) object moves along a continuous trajectory to a more complex display in which two 3D objects undergo trajectories that are interrupted behind an occluder. Six-month-old infants saw an occlusion sequence in which a ball moved along a linear path, disappeared behind a rectangular screen, and then a ball (ball-ball event) or a box (ball-box event) emerged at the other edge. An eye-tracking system recorded infants' eye-movements during the event sequence. Results from examination of infants' attention to the occluder indicate that during the occlusion interval infants looked longer to the side of the occluder behind which the moving occluded object was located, shifting gaze from one side of the occluder to the other as the object(s) moved behind the screen. Furthermore, when events included two objects, infants attended to the spatiotemporal coordinates of the objects longer than when a single object was involved. These results provide clear evidence that infants' visual tracking is different in response to a one-object display than to a two-object display. Furthermore, this finding suggests that infants may require more focused attention to the hidden position of objects in more complex multiple-object displays and provides additional evidence that infants represent the spatial location of moving occluded objects.     

The shared signal hypothesis: Effects of emotion‐gaze congruency in infant and adult visual preferences

In this study, 4‐month‐old infants’ and adults’ spontaneous preferences for emotional and neutral displays with direct and averted gaze are investigated using visual preference paradigms. Specifically, by presenting two approach‐oriented emotions (happiness and anger) and two avoidance‐oriented emotions (fear and sadness), we asked whether the pattern of emotion–gaze interaction suggested by the shared signal hypothesis (SSH) would also be found with this paradigm. Both age groups demonstrated an ability to discern the approach‐ and avoidance‐oriented emotions, matching them with direct and averted gaze, respectively. Nonetheless, infants showed a greater sensitivity for the congruent emotion‐gaze combination in the approach‐oriented emotions, while adults were equally sensitive to the gaze‐expression congruence for both the approach‐ and avoidance‐oriented emotions. In a follow‐up experiment, infants showed no preference for direct or averted gaze in the context of neutral faces. We conclude that the SSH may have validity from infancy, gradually extending from approach‐oriented emotions to avoidance‐oriented emotions over the course of development.     

On the origins of background emotions: from affect synchrony to symbolic expression

Guided by Damasio's (2003) formulations on background emotions, this study examined the contour of infant affect during interactions with mother and father in relation to the emergence of symbolic expression. One hundred parents and infants were observed in face-to-face interactions and in play sessions at the toddler stage. Parent's and infants' affective states were coded in 1-s frames, and synchrony was assessed. Toddlers' play was microcoded for symbolic level and for reciprocity and intrusiveness. Infant affective contour with mother was rhythmic with 1 episode of positive arousal framed by social gaze. Affective contour with father contained several peaks of positive arousal of shorter duration. Symbolic complexity was comparable and preserved the parent-specific contours, with quicker latencies, higher frequencies, and shorter durations of complex symbolic episodes with father. Sequential relations emerged between parent's and child's symbolic expression, and maternal reciprocity and intrusiveness were sequentially linked to symbolic expansion or constriction, respectively. Parent-infant synchrony and the parent's support of toddler symbolic play predicted symbolic complexity. The need to include time in research on emotions and the dyadic origins of positive emotions are discussed.     

12-month-old infants allocate increased neural resources to stimuli associated with negative adult emotion

Young infants use caregivers' emotional expressions to guide their behavior in novel, ambiguous situations. This skill, known as social referencing, likely involves at least 3 separate abilities: (a) looking at an adult in an unfamiliar situation, (b) associating that adult's emotion with the novel situation, and (c) regulating their own emotions in response to the adult's emotional display. The authors measured each of these elements individually as well as how they related to each other. The results revealed that 12-month-olds allocated more attention, as indicated by event-related potential measures, to stimuli associated with negative adult emotion than to those associated with positive or neutral emotion. Infants' interaction with their caregiver was affected by adult emotional displays. In addition, how quickly infants referenced an adult predicted both their brain activity in response to pictures of stimuli associated with negative emotion as well as some aspects of their behavior regulation. The results are discussed with respect to their significance for understanding why infants reference and regulate their behavior in response to adult emotion. Suggestions for further research are provided.     

How infants relate looker and object: evidence for a perceptual learning account of gaze following in infancy

In two experiments, it was investigated how preverbal infants perceive the relationship between a person and an object she is looking at. More specifically, it was examined whether infants interpret an adult's object-directed gaze as a marker of an intention to act or whether they relate the person and the object via a mechanism of associative learning. Fourteen-month-old infants observed an adult gazing repeatedly at one of two objects. When the adult reached out to grasp this object in the test trials, infants showed no systematic visual anticipations to it (i.e. first visual anticipatory gaze shifts) but only displayed longer looking times for this object than for another before her hand reached the object. However, they showed visual anticipatory gaze shifts to the correct action target when only the grasping action was presented. The second experiment shows that infants also look longer at the object a person has been gazing at when the person is still present, but is not performing any action during the test trials. Looking preferences for the objects were reversed, however, when the person was absent during the test trials. This study provides evidence for the claim that infants around 1 year of age do not employ other people's object-directed gaze to anticipate future actions, but to establish person-object associations. The implications of this finding for theoretical conceptions of infants' social-cognitive development are discussed.     

Décalage in infants' knowledge about occlusion and containment events: Converging evidence from action tasks

In the present research, 6-month-old infants consistently searched for a tall toy behind a tall as opposed to a short occluder. However, when the same toy was hidden inside a tall or a short container, only older, 7.5-month-old infants searched for the tall toy inside the tall container. These and control results (1) confirm previous violation-of-expectation (VOE) findings of a décalage in infants' reasoning about height information in occlusion and containment events; (2) cast doubt on the suggestion that VOE tasks overestimate infants' cognitive abilities; and (3) support recent proposals that infants use their physical knowledge to guide their actions when task demands do not overwhelm their limited processing resources.     

To see or not to see: infants prefer to follow the gaze of a reliable looker

In two experiments, we examined whether 14‐month‐olds understand the subjective nature of gaze. In the first experiment, infants first observed an experimenter express happiness as she looked inside a container that either contained a toy (reliable looker condition) or was empty (unreliable looker condition). Then, infants had to follow the same experimenter's gaze to a target object located either behind or in front of a barrier. Infants in the reliable looker condition followed the experimenter's gaze behind the barrier more often than infants in the unreliable looker condition, whereas both groups followed the experimenter's gaze to the target object located in front of the barrier equally often. In the second experiment, infants did not generalize their knowledge about the unreliability of a looker to a second ‘naïve’ looker. These findings suggest that 14‐month‐old infants adapt their gaze following as a function of their past experience with the looker.