Previous research indicates that infants' prediction of the goals of observed actions is influenced by own experience with the type of agent performing the action (i.e., human hand vs. non-human agent) as well as by action-relevant features of goal objects (e.g., object size). The present study investigated the combined effects of these factors on 12-month-olds' action prediction. Infants' (N=49) goal-directed gaze shifts were recorded as they observed 14 trials in which either a human hand or a mechanical claw reached for a small goal area (low-saliency goal) or a large goal area (high-saliency goal). Only infants who had observed the human hand reaching for a high-saliency goal fixated the goal object ahead of time, and they rapidly learned to predict the action goal across trials. By contrast, infants in all other conditions did not track the observed action in a predictive manner, and their gaze shifts to the action goal did not change systematically across trials. Thus, high-saliency goals seem to boost infants' predictive gaze shifts during the observation of human manual actions, but not of actions performed by a mechanical device. This supports the assumption that infants' action predictions are based on interactive effects of action-relevant object features (e.g., size) and own action experience.

A conversation is made up of visual and auditory signals in a complex flow of events. What is the relative importance of these components for young children's ability to maintain attention on a conversation? In the present set of experiments the visual and auditory signals were disentangled in four filmed events. The visual events were either accompanied by the speech sounds of the conversation or by matched motor sounds and the auditory events by either the natural visual turn taking of the conversation or a matched turn taking of toy trucks. A cornea-reflection technique was used to record the gaze-pattern of subjects while they were looking at the films. Three age groups of typically developing children were studied; 6-month-olds, 1-year-olds and 3-year-olds. The results show that the children are more attracted by the social component of the conversation independent of the kind of sound used. Older children find spoken language more interesting than motor sound. Children look longer at the speaking agent when humans maintain the conversation. The study revealed that children are more attracted to the mouth than to the eyes area. The ability to make more predictive gaze shifts develops gradually over age.

At 3 months of age, reaching behavior was measured in a group of 10 girls and 10 boys born at term. The assessments were carried out on the average 2 days after reaching onset. Reaching kinematics was measured in both supine and reclined positions. Girls reached more than boys, had straighter reaching trajectories and movements of shorter durations as well as fewer movement units. The reclined position gave rise to straighter trajectories in both girls and boys. Several anthropometric parameters were measured. Girls had less length and volume of the forearm than boys but similar upper arm volumes. There was a weak relation between kinematic and anthropometric variables.

Investigating infants’ ability to match visual and auditory speech segments presented sequentially allows us to understand more about the type of information they encode in each domain, as well as their ability to relate the information. One previous study found that 4.5- month-old infants’ preference for visual French or German speech depended on whether they had previously heard the respective language, suggesting a remarkable ability to encode and relate audio-visual speech cues and to use these to guide their looking behavior. However, French and German differ in their prosody, meaning that perhaps, the infants did not base their matching on phonological or phonetic cues, but on prosody patterns. The present study aimed to address this issue by tracking the eye gaze of 4.5-month-old German and Swedish infants cross-culturally in an intersensory matching procedure, comparing German and Swedish, two same-rhythm-class languages differing in phonetic and phonological attributes but not in prosody. Looking times indicated that even when distinctive prosodic cues were eliminated, 4.5- month-olds were able to extract subtle language properties and sequentially match visual and heard fluent speech. This outcome was the same for different individual speakers for the two modalities, ruling out the possibility that the infants matched speech patterns specific to one individual. This study confirms a remarkably early emerging ability of infants to match auditory and visual information. The fact that the types of information were matched despite sequential presentation demonstrates that the information is retained in short term memory, and thus goes beyond purely perceptual – here-and-now processing.

The goal of this study was to investigate some of the visuo-motor factors underlying an infant's developing ability to grasp a laterally-moving object. In particular, hand preference, midline crossing, and visual-field asymmetry were investigated by comparing performance as a function of the object's direction of motion. We presented 6-, 8-, and 10-month-old infants with a graspable object, moving in a circular trajectory in the horizontal plane. Six-month-old infants reached for the object with the ipsilateral hand and grasped it with the contralateral hand. Eight-month-old infants showed a strong right-hand bias for both reaching and grasping. Ten-month-old infants showed a greater diversity of strategy use including bimanual and successful ipsilateral grasping following ipsilateral reaching in both directions of motion. Thus, motor constraints due to spatial compatibility, hand preference and bimanual coordination (but not midline crossing) must be taken into account to understand age differences in grasping a moving object.

Across two experiments, we examined the relationship between 18-month-old infants' mimicry and social behavior - particularly invitations to play with an adult play partner. In Experiment 1, we manipulated whether an adult mimicked the infant's play or not during an initial play phase. We found that infants who had been mimicked were subsequently more likely to invite the adult to join their play with a new toy. In addition, they reen-acted marginally more steps from a social learning demonstration she gave. In Experiment 2, infants had the chance to spontaneously mimic the adult during the play phase. Complementing Experiment 1, those infants who spent more time mimicking the adult were more likely to invite her to play with a new toy. This effect was specific to play and not apparent in other communicative acts, such as directing the adult's attention to an event or requesting toys. Together, the results suggest that infants use mimicry as a tool to establish social connections with others and that mimicry has specific influences on social behaviors related to initiating subsequent joint interactions.

The abilities to flexibly allocate attention, select between conflicting stimuli, and make anticipatory gaze movements are important for young children's exploration and learning about their environment. These abilities constitute voluntary control of attention and show marked improvements in the second year of a child's life. Here we investigate the effects of visual distraction and delay on 18-month-olds' ability to predict the location of an occluded target in an experiment that requires switching of attention, and compare their performance to that of adults. Our results demonstrate that by 18 months of age children can readily overcome a previously learned response, even under a condition that involves visual distraction, but have difficulties with correctly updating their prediction when presented with a longer time delay. Further, the experiment shows that, overall, the 18-month-olds' allocation of visual attention is similar to that of adults, the primary difference being that adults demonstrate a superior ability to maintain attention on task and update their predictions over a longer time period. (C) 2014 Elsevier Inc. All rights reserved.

We used eye-tracking technique to examine gaze shifts of 9-, 16-, and 24-month-old infants who were presented with still images of a conversation between two individuals facing each other or turning away from each other. The results showed that body orientation, as measured by the face-to-face effect, is sufficient to provide infants with crucial information about others’ social engagement.

A relationship between elicited imitation in neanates and social interaction hasbeen proposed by several investigators. The present work examines if such arelationship can be found when studying neonatal imitation, gaze aversion, andmother-inFant interaction. Thirty-two infants were observed at 2 to 3 days, 3weeks, and 3 months of age. imitation of tongue protrusion and mouth openingwas assessed in all three observations. in addition, a face-to-face interactionbetween mother and child was included when the child reached 3 months of age_The most striking result was a negative relationship between the infants' briefgaze aversion observed at 3 months of age while interacting with their mothersand 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 displayfewer episodes of brief gaze aversion when interacting with their mothers.

Previous literature suggests that attention processes such as sustained attention would con-stitute a developmental foundation for the self-regulatory functions executive functioningand effortful control (e.g., Garon, Bryson, & Smith, 2008; Rothbart, Derryberry, & Posner,1994). Our main aim was to test this hypothesis by studying whether sustained attentionat age 1 year can predict individual differences in self-regulatory functions at age 2 years.Longitudinal data from 66 infants and their parents were included in the study. Sustainedattention was assessed during free play at age 1 year; executive functioning, measured usingan eye-tracking version of the A-not-B task, and effortful control, measured using parentalratings, were assessed at both age 1 and age 2 years. The results did support a longitudinalprediction of individual differences in 2-year-olds’ self-regulatory functions as a function ofsustained attention at age 1 year. We also found significant improvement in both executivefunctioning and effortful control over time, and the two self-regulatory constructs wererelated in toddlerhood but not in infancy. The study helps increase our understanding ofthe early development of self-regulatory functions necessary for identifying developmentalrisks and, in the future, for developing new interventions.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects social communication skills and flexible behaviour. Developing new treatment approaches for ASD requires early identification of the factors that influence later behavioural outcomes. One fruitful research paradigm has been the prospective study of infants with a first degree relative with ASD, who have around a 20% likelihood of developing ASD themselves. Early findings have identified a range of candidate neurocognitive markers for later ASD such as delayed attention shifting or neural responses to faces, but given the early stage of the field most sample sizes are small and replication attempts remain rare. The Eurosibs consortium is a European multisite neurocognitive study of infants with an older sibling with ASD conducted across nine sites in five European countries. In this manuscript, we describe the selection and standardization of our common neurocognitive testing protocol. We report data quality assessments across sites, showing that neurocognitive measures hold great promise for cross-site consistency in diverse populations. We discuss our approach to ensuring robust data analysis pipelines and boosting future reproducibility. Finally, we summarise challenges and opportunities for future multi-site research efforts.

The purpose of this study was to investigate infant’s predictive head-tracking relatively to a linearly moving object. Object’s motion was  produced by a large computer controlled plotter, tilted 15 degrees  forward from vertical position. The objects moved on a white  ainted  aluminum sheet (98x 130 cm). Objects were presented in three different conditions. It was either visible all the time, occluded during part of its motion, or the room lights were extinguished during part of the object’s motion. Infant’s head movements were recorded by two infrared cameras and mixed onto a single video screen. Each infant was shown 6 initial and 6 final visible trials, and 6 times 2 occlusion trials in between, occlusion either by occluder or extinguished light. Sticky paper was placed on the infant’s head and by a touch-screen technology the markers were coded every 100 msec.

The purpose was to investigate associations between quality of reaching for moving objects at 8 months corrected age and neurodevelopment at 2.5 years in children born very preterm (gestational age (GA), 24–31 weeks). Thirtysix infants were assessed while reaching for moving objects. The movements were recorded by a 3D motion capture system. Reaching parameters included aiming, relative length of the reach, number of movement units, proportion of bimanual coupled reaches and number of hits. Neurodevelopment was assessed at 2.5 years by the Bayley Scales of Infant Development III. There were strong associations between infant reaching kinematics and neurodevelopment of cognition and language but the patterns differed: in children born extremely preterm (GA < 28 weeks), planning and control of reaching was strongly related to outcome, while in children born very preterm (GA 28–31 weeks) number of hits and bimanual strategies were of greater relevance. In conclusion, for extremely preterm infants, basic problems on how motion information is incorporated with action planning prevail, while in very preterm infants the coordination of bimanual reaches is more at the focus. We conclude that the results reflect GA related differences in neural vulnerability and that early motor coordination deficits have a cascading effect on neurodevelopment.

Infant sensitivity to motion relationships specifying certain complex events, such as a person walking, has recently been demonstrated, but the perceptual principles underlying early event perception are not well understood. Retinal motion toward a common point (concurrent motion) specifies translation in depth to adult perceivers in the absence of conflicting information (Börjesson & von Hofsten, 1973). We tested this principle of event perception with 28 16-week-old infants. One group was habituated in a dark room to a concurrent motion: three points of light moving in a frontoparallel plane toward and away from a central point (not seen). After habituation, the room was illuminated, and looking time was tested to alternate presentations of two displays. In one display (depth motion), three lights were attached to a triangle actually moving in depth; in the other display (surface motion), the three lights moved visibly along the surface of a fronto-parallel stationary triangle. If concurrent motion, in the absence of conflicting information, specifies motion in depth to infants, they were expected to look longer after habituation at the surface motion display. A control group tested infants' relative interest in the two test displays with no prior habituation period.

Control-group infants marginally preferred the depth movement display. The habituation group responded three times as much to the surface motion display, suggesting that motion in depth had been perceived during habituation. Specification of motion in depth by concurrency of relative proximal stimulus motions seems to be an operative principle in infants' perception; moreover, at least some principles of early event perception are unrelated to person perception or biological motion. The relation of these results to recent findings in infant object perception is discussed.

Infants early visual preferences for faces, and their observational learning abilities, are well-established in the literature. The current study examines how infants attention changes as they become increasingly familiar with a person and the actions that person is demonstrating. The looking patterns of 12- (n = 61) and 16-month-old infants (n = 29) were tracked while they watched videos of an adult presenting novel actions with four different objects three times. A face-to-action ratio in visual attention was calculated for each repetition and summarized as a mean across all videos. The face-to-action ratio increased with each action repetition, indicating that there was an increase in attention to the face relative to the action each additional time the action was demonstrated. Infants prior familiarity with the object used was related to face-to-action ratio in 12-month-olds and initial looking behavior was related to face-to-action ratio in the whole sample. Prior familiarity with the presenter, and infant gender and age, were not related to face-to-action ratio. This study has theoretical implications for face preference and action observations in dynamic contexts.

The goal of this study was to compare the temperamental properties (i.e. Surgency/extraversion, Negative affectivity, Effortful control) of institution-reared (IR) and family-reared (FR) toddlers, aged between 17-37 months, living in Simferopol, Crimea. The results demonstrated significantly lower Surgency and higher Negative affectivity scores in the institution-reared toddlers. At the same time, in IR children Surgency scores depended on children’s age, the older the children were, the higher scores they were assigned. No such relation was found for FR toddlers. Further, level of Negative affectivity in IR group depended significantly on amount of time that children spent at the institution; more time resulted in higher Negative affectivity scores. We could not find any differences between IR and FR children in Effortful control.

The study results suggest different developmental patterns for Surgency and Negative affectivity in IR and FR children and are discussed in terms of potential impact it may have on further personality development.

This study forms part of a longitudinal investigation of early infant social withdrawal, maternal symptoms of depression and later child social emotional functioning. The sample consisted of a group of full-term infants (N = 238) and their mothers, and a group of moderately premature infants (N = 64) and their mothers. At 3 months, the infants were observed with the Alarm Distress Baby Scale (ADBB) and the mothers completed the Edinburgh Postnatal Depression Scale (EPDS). At 12 months, the mothers filled out questionnaires about the infants social emotional functioning (Infant Toddler Social Emotional Assessment and the Ages and Stages Questionnaire-Social Emotional). At 3 months, as we have previously shown, the premature infants had exhibited more withdrawal behavior and their mothers reported elevated maternal depressive symptoms as compared with the full-born group. At 12 months the mothers of the premature infants reported more child internalizing behavior. These data suggest that infant withdrawal behavior as well as maternal depressive mood may serve as sensitive indices of early risk status. Further, the results suggest that early maternal depressive symptoms are a salient predictor of later child social emotional functioning. However, neither early infant withdrawal behavior, nor gestational age, did significantly predict social emotional outcome at 12 months. It should be noted that the differences in strength of the relations between ADBB and EPDS, respectively, to the outcome at 12 months was modest. An implication of the study is that clinicians should be aware of the complex interplay between early infant withdrawal and signs of maternal postpartum depression in planning ports of entry for early intervention. (C) 2016 Elsevier Inc. All rights reserved.

What do infants know about hidden objects’? Previous research suggests that the answer depends on how the objects are hidden. For instance, infants appear to reach for toys in the dark (Clifton, Rochat, Litovsky, & Penis, 1991; Hood & Willatts, 1986) before they reach for toys occluded in the light. However, these experiments have not compared directly toys occluded in the light and by darkness. The current experiment tests infants under both conditions in the same paradigm. In addition, the experiment introduces a combined ccluderdarkness condition to test two distinct explanations for a possible advantage in the dark. First,  infants may have knowledge about hidden objects but cannot act on it for occluder-specific reasons (e.g., means-ends deficits, beliefs about the whether the object is accessible). Second, infants may have graded representations of occluded objects that can be more easily maintained in the face of global darkness than with the direct visual interference of an occluder. Counterintuitive results from the current experiment provide evidence for both representational and occluder-specific effects.

Autism spectrum disorder (ASD) likely emerges from a complex interaction between pre-existing neurodevelopmental vulnerabilities and the environment. The interaction with parents forms a key aspect of an infant’s social environment, but few prospective studies of infants at elevated likelihood (EL) for ASD (who have an older sibling with ASD) have examined parent-child interactions in the first year of life. As part of a European multisite network, parent-child dyads of free play were observed at 5 months (62 EL infants, 47 infants at typical likelihood (TL)) and 10 months (101 EL siblings, 77 TL siblings). The newly-developed Parent-Infant/Toddler Coding of Interaction (PInTCI) scheme was used, focusing on global characteristics of infant and parent behaviors. Coders were blind to participant information. Linear mixed model analyses showed no significant group differences in infant or parent behaviors at 5 or 10 months of age (all ps≥0.09, d≤0.36), controlling for infant’s sex and age, and parental educational level. However, without adjustments, EL infants showed fewer and less clear initiations at 10 months than TL infants (p = 0.02, d = 0.44), but statistical significance was lost after controlling for parental education (p = 0.09, d = 0.36), which tended to be lower in the EL group. Consistent with previous literature focusing on parent-infant dyads, our findings suggest that differences between EL and TL dyads may only be subtle during the first year of life. We discuss possible explanations and implications for future developmental studies.

Visual attention plays a key role in infants' interaction with the environment, and shapes their behavioral and brain development. As such, early problems with flexibly switching gaze from one stimulus to another (visual disengagement) have been hypothesized to lead to developmental difficulties (e.g. joint attention and social skills) over time. This study aimed to identify crosssectional associations between performance in the Gap task (gaze shift latencies and visual attention disengagement) and measures of development and adaptive behavior in conjunction to any sex or socioeconomic status effects in infancy. We measured visual attention disengagement in 436 5-month-old infants and calculated its association with cognitive developmental level, adaptive behaviours, socioeconomic status (SES) and biological sex. In the Gap task, participants must redirect their gaze from a central stimulus to an appearing peripheral stimulus. The three experimental conditions of the task (Gap, Baseline and Overlap) differ on the timepoint when the central stimuli disappears in relation to the appearance of the peripheral stimulus: 200 ms before the peripheral stimulus appears (Gap), simultaneously to its appearance (Baseline), or with peripheral stimulus offset (Overlap). The data from the experimental conditions showed the expected pattern, with average latencies being the shortest in the Gap and longest in the Overlap condition. Females were faster (p = .004) than males in the Gap condition, which could indicate that arousal-related effects differ as a function of biological sex. Infants from higher SES were slower (p =.031) in the Overlap condition compared to lower SES infants. This suggests that basic visual attention may differ by socio-cultural background, and should be considered when studying visual attention and its developmental correlates. We observed no significant association to concurrent developmental level or adaptive function. Given its large sample size, this study provides a useful reference for future studies of visual disengagement in early infancy.

Human actions are often embedded in contexts of social interactions. However, just a few studies that have explored the development of infants' understanding of other people's manual actions do take this variable into account. In this study, 10- and 18-month-old infants were shown three interactive manual actions which the infants could or could not perform themselves. The infants' gaze shifts to the action target were recorded with an eye tracker. The results indicated that 18-month-old infants look faster to the target than their younger counterparts when they observe actions that they can perform themselves. The results suggest that the infants' own capacity to perform an action facilitates understanding of the goal of the action in a social interaction.

Human actions are often embedded in contexts of social interactions. However, just a few studies that have explored the development of infants' understanding of other people's manual actions do take this variable into account. In this study, 10- and 18-month-old infants were shown three interactive manual actions which the infants could or could not perform themselves. The infants' gaze shifts to the action target were recorded with an eye tracker. The results indicated that 18-month-old infants look faster to the target than their younger counterparts when they observe actions that they can perform themselves. The results suggest that the infants' own capacity to perform an action facilitates understanding of the goal of the action in a social interaction.

The study explored 6-month-old infants' ability to follow a pointing gesture in a dynamic social context. The infants were presented with a video of a model pointing to one of two toys. The pointing gesture was performed either normally (with arm and hand pointing at the same direction), with a stick, or the model's arm and hand pointing in different directions (at different toys). The results indicate that infants at this age reliably followed pointing performed normally.

The study explored 6-month-old infants' ability to follow a pointing gesture in a dynamic social context. The infants were presented with a video of a model pointing to one of two toys. The pointing gesture was performed either normally (with arm and hand pointing at the same direction), with a stick, or the model's arm and hand pointing in different directions (at different toys). The results indicate that infants at this age reliably followed pointing performed normally.

A head-mounted camera was used for studying infant focus of attention. In two situations, 10- and 14-month-old infants observed two adults interacting. In one situation, the adults had a conversation and in the other situation, they were playing with blocks. The results indicate a preference for observing manual actions and a different pattern in looking at conversations than has been shown in eye-tracking studies. The head-mounted camera is a promising method for examining the infant's focus of attention.

A head-mounted camera was used for studying infant focus of attention. In two situations, 10- and 14-month-old infants observed two adults interacting. In one situation, the adults had a conversation and in the other situation, they were playing with blocks. The results indicate a preference for observing manual actions and a different pattern in looking at conversations than has been shown in eye-tracking studies. The head-mounted camera is a promising method for examining the infant's focus of attention.

Exploratory behaviors of 9 late preterm infants and 10 full-term infants were evaluated longitudinally at 5, 6 and 7. months of age. Eight exploratory behaviors were coded. The preterm infants mouthed the object less and had delayed gains in Waving compared to the full-term infants.

Abstract In two experiments we examined the influence of contingent versus non-contingent responding on infant social referencing behavior. EXPERIMENT 1: Forty 12-month-old infants were exposed to an ambiguous toy in a social referencing situation. In one condition an unfamiliar adult who in a previous play situation had responded contingently to the infant’s looks gave the infant positive information about the toy. In the other condition an unfamiliar adult who previously had not responded contingently delivered the positive information. EXPERIMENT 2: Forty-eight 12-month-old infants participated in Experiment 2. In this experiment it was examined whether the familiarity of the adult influences infants’ reactions to contingency in responding. In one condition a parent who previously had responded contingently to the infant’s looks provided positive information about the ambiguous toy, and in the other condition a parent who previously had not responded contingently provided the positive information. The infants looked more at the contingent experimenter in Experimenter 1, and also played more with the toy after receiving positive information from the contingent experimenter. No differences in looking at the parent and in playing with the toy were found in Experiment 2. The results indicate that contingency in responding, as well as the familiarity of the adult, influence infants’ social referencing behavior.

In two experiments we examined the influence of contingent versus non-contingent responding on infant social referencing behavior. EXPERIMENT 1: Forty 12-month-old infants were exposed to an ambiguous toy in a social referencing situation. In one condition an unfamiliar adult who in a previous play situation had responded contingently to the infant's looks gave the infant positive information about the toy. In the other condition an unfamiliar adult who previously had not responded contingently delivered the positive information. EXPERIMENT 2: Forty-eight 12 month-old infants participated in Experiment 2. In this experiment it was examined whether the familiarity of the adult influences infants' reactions to contingency in responding. In one condition a parent who previously had responded contingently to the infant's looks provided positive information about the ambiguous toy, and in the other condition a parent who previously had not responded contingently provided the positive information. The infants looked more at the contingent experimenter in Experimenter 1, and also played more with the toy after receiving positive information from the contingent experimenter. No differences in looking at the parent and in playing with the toy were found in Experiment 2. The results indicate that contingency in responding, as well as the familiarity of the adult, influence infants' social referencing behavior.

We examined the effect of adults’ contingency in responding to infants’ behavior in an ambiguous situation in two experiments. In Experiment 1, forty-four 12-month-old infants were exposed to an ambiguous toy. An unfamiliar adult responded either contingently or non-contingently to the infant’s bids and then presented the toy and provided positive information. During toy presentation, infants in the non-contingent condition looked less at the experimenter than infants in the contingent condition. In a concluding free-play situation infants in the non-contingent condition played less and tended to touch the toy less. In Experiment 2 (forty-four 12-month-old infants), the parent either responded promptly or with a delay each time the infant made contact initiatives and then presented an ambiguous toy and delivered the positive information. The infants in the non-contingent condition tended to look less at the parent during toy presentation and also tended to play less with the toy during the concluding free-play situation. The findings show that adults’ contingency in responding influences infants’ behavior in ambiguous situations.

This longitudinal study investigates the relation between recall memory and communication in infancy and later cognitive development. Twenty-six typically developing Swedish children were tested during infancy for deferred imitation (memory), joint attention (JA), and requesting (nonverbal communication), they also were tested during childhood for language and cognitive competence. Results showed that infants with low performance on both deferred imitation at 9 months and joint attention at 14 months obtained a significantly lower score on a test of cognitive abilities at 4 years of age. This long-term prediction from preverbal infancy to childhood cognition is of interest both to developmental theory and to practice. © 2006 Elsevier Inc. All rights reserved.

Infants expect people to direct actions toward objects, and they respond to actions directed to themselves, but do they have expectations about actions directed to third parties? In two experiments, we used eye tracking to investigate 1- and 2-year-olds' expectations about communicative actions addressed to a third party. Experiment 1 presented infants with videos where an adult (the Emitter) either uttered a sentence or produced non-speech sounds. The Emitter was either face-to-face with another adult (the Recipient) or the two were back-to-back. The Recipient did not respond to any of the sounds. We found that 2-, but not 1-year-olds looked quicker and longer at the Recipient following speech than non-speech, suggesting that they expected her to respond to speech. These effects were specific to the face-to-face context. Experiment 2 presented 1-year-olds with similar face-to-face exchanges but modified to engage infants and minimize task demands. The infants looked quicker to the Recipient following speech than non-speech, suggesting that they expected a response to speech. The study suggests that by 1 year of age infants expect communicative actions to be directed at a third-party listener.

The positive clinical effects caused by skin-to-skin contact immediately after birth or after repeated skin-to-skin contact of premature infants (kangaroo care) or fullterm infants are well documented in the literature. However, information regarding the physiological mechanisms mediating these effects are surprisingly scarce and incomplete. In this article the oxytocinergic system and the cutaneous sensory pathways by which the oxytocinergic system is activated in response to skin-to-skin contact are presented in more detail. In addition, we discuss how the effects of skin-to-skin treatment can be attributed to different aspects of the effect spectrum of the oxytocinergic or calm and connection system.

The structure of the oxytocinergic system, comprising the peripheral (circulating, hormonal) and the central (neurotransmitter) components, as well as, the pathways and mechanisms by which these functions are coordinated are described. Also the various effects induced by the oxytocinergic system (the calm and connection system) are reviewed.

The sensory pathways, which include visual, auditory, olfactory and tactile stimuli, given and received by both mother and newborn and which activate the oxytocinergic system in response to skin-to-skin contact, are reviewed. A special emphasis is placed on the role of cutaneous sensory nerves and their activation by touch, light pressure and in particular warmth. The important role of the rise and the pulsatility of maternal temperature in mediating the positive effects of skin-to-skin contact in the newborn is highlighted. The concept of maternal giving of warmth and its possible link to the experience of trust and safety in the newborn is discussed from an evolutionary perspective.

The effects induced by skin-to-skin contact can be attributed to the different functions of the oxytocinergic system. Ameliorated social interaction (e.g., more tactile and auditory interaction, more sensitive and synchronous interaction between mother and baby, the baby’s crawling behavior) are expressions of oxytocin’s ability to stimulate social interaction. The decreased levels of fear and stress are expressions of oxytocin’s ability to reduce the activity of the amygdala and of the stress system, e.g. the activity in the HPA-axis and the sympathetic nervous system. Increased HRV, increased activity in endocrine system of the gastrointestinal tract as well as stimulation of growth and maturation are examples of oxytocin’s ability to stimulate the activity of the parasympathetic nervous system and other peripheral and central mechanisms related to restoration and growth.

The propensity of different types of treatment with skin-to-skin contact to induce long-term effects is also highlighted. We propose that the sustained effects caused by skin-to-skin contact are induced by an enduring shift in the balance between the oxytocinergic system (the calm and connection system) and the stress system (fight flight reaction) in favor of the oxytocinergic system. This shift leads to a sustained decrease in the HPA-axis and the sympathetic nervous system probably involving alpha 2-adrenoceptors.

It is of clinical importance to be aware of the mechanisms by which skin-to-skin contact induces short and longterm positive effects in parents and newborns. If ward routines are adapted to ascertain a maximal stimulation of these mechanisms, the function of the oxytocinergic system will be optimized, which will be linked to a better clinical outcome for parents and newborns.