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.     

Comparison of Maternal Perceptions of Preterm and Fullterm Infants

We compared maternal attitudes and feelings in two groups of mother–infant dyads: 25 mothers with preterm newborns (M=30.9 weeks of gestational age) and 25 mothers with fullterm newborns (M=39.7 weeks of gestational age). Both groups were matched for infant sex, age (corrected in preterms) and birth order as well as for maternal age and education. Semi-structured interviews were used to collect data on maternal attitudes and feelings about pregnancy and the first contacts with the newborn. Mothers completed rating scales to indicate the specific behavioural problems they perceived in their infants at 6 weeks and 3 months of (corrected) age. Observations of infant responses to visual and/or auditory stimuli were made at 6 weeks and 3 months in a laboratory setting. At 3 months, each infant was administered the Bayley Scale of Mental Development. There were no differences in maternal attitudes and feelings between the two groups of mothers prior to the birth. However, significant differences appeared after birth and indicated increased anxiety in mothers of preterm infants. Significantly more 6-week-old preterm infants were perceived by their mothers as irritable and to cry more than fullterm infants. At the age of 3 months, both groups of infants differed only in terms of irritability. Differences between the two groups of mother–infant dyads, age-related changes in these differences and relationships between maternal evaluations and the laboratory-based assessments are discussed in the context of contrasts in the stability of behavioural regulation in preterm and fullterm infants.     

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.     

Associations between the developmental trajectories of visual scanning and disengagement of attention in infants

The relation between the developmental trajectories of visual scanning and disengagement of attention and gaze were examined throughout early infancy. A sample of 10 infants carried out a scanning and a disengagement task with the same visual stimuli six times between 6 and 26 weeks of age. Frequency and latency measures were analyzed using multivariate multilevel models and Monte Carlo analyses. The results suggest that the ability to scan a face or an abstract stimulus evolves slightly earlier than the ability to shift gaze to a newly appeared target in the periphery. This is consistent with the account that the parvocellular stream becomes functional slightly before the magnocellular stream. The study revealed no indications of a positive association between the development of scanning and disengagement on the level of the individual infant. Scanning and disengagement change scores contrasted more with one another than could be expected on the basis of chance. This implies that the magnocellular and the parvocellular stream develop rather independently up to the age of 26 weeks.     

Reduced Alternating Gaze During Social Interaction in Infancy is Associated with Elevated Symptoms of Autism in Toddlerhood

In typical development, infants often alternate their gaze between their interaction partners and interesting stimuli, increasing the probability of joint attention toward surrounding objects and creating opportunities for communication and learning. Children with Autism Spectrum Disorder (ASD) have been found to engage less in behaviors that can initiate joint attention compared to typically developing children, but the role of such atypicalities in the development of ASD during infancy is not fully understood. Here, using eye tracking technology in a live setting, we show that 10-month-olds at high familial risk for ASD engage less in alternating gaze during interaction with an adult compared to low risk infants. These differences could not be explained by low general social preference or slow visual disengagement, as the groups performed similarly in these respects. We also found that less alternating gaze at 10 months was associated with more social ASD symptoms and less showing and pointing at 18 months. These relations were similar in both the high risk and the low risk groups, and remained when controlling for general social preference and disengagement latencies. This study shows that atypicalities in alternating gaze in infants at high risk for ASD emerge already during the first 10 months of life - a finding with theoretical as well as potential practical implications.     

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.     

Visual attention skills of premature infants with and without intraventricular hemorrhage

The relation between two medical complications associated with prematurity (intraventricular hemorrhage (IVH) and respiratory distress syndrome (RDS)) and visual attention skills of very low birth-weight (VLBW) infants were examined. Fourteen preterm VLBW infants with IVH and RDS, 9 preterms with RDS and no IVH, and 10 full-term infants matched on SES, sex, and race were assessed at 7 months of age (after correction for prematurity) for their ability to show a decremental response to a familiar visual stimulus and an increment in response to a novel visual stimulus. Measures of attention getting (turning toward a stimulus) and attention holding (sustained fixation on the stimulus after turning) were taken. On the attention-getting measures, IVH-RDS preterms had longer latencies than both the RDS-no-IVH preterm group and the full-term group. There were no group differences on attention-holding measures. The three groups did not differ in habituation to the familiar visual stimulus or discrimination of the novel stimulus. This study indicates that the early visual attention skills of preterm infants are differentially affected by specific types of prenatal complications.     

Processing speed in the 1st year of life: a longitudinal study of preterm and full-term infants

Processing speed was assessed at 5, 7, and 12 months in full-term and preterm infants (birth-weight < 1,750 g). Speed was gauged directly in a new task by presenting infants with a series of paired faces, one that remained the same across trials and one that changed; trials continued until infants showed a consistent novelty preference. At all ages, preterms required about 20% more trials and 30% more time than full-terms to reach criterion. Among preterms, slower processing was associated with greater medical risk (e.g., respiratory distress syndrome). Developmental trajectories for speed (and attention) were similar for both groups. Thus, the deficits in processing speed previously found for preterms in childhood are already present in the 1st year of life.     

Face-to-face interaction in term and preterm infants

Previous research has found that mothers of preterm infants work harder in a face-to-face situation with their infants than mothers of term infants. Data have also revealed that preterm infants are less responsive than term infants in a social interaction. To date, there have been few studies that have attempted to determine the range of facial expressive cues that preterms may be emitting or the possible physiological basis for this behavior. In an attempt to investigate these questions, preterm and term infants were observed in a face-to-face situation. Prior to the session, three minutes of resting EKG was recorded. The infant's facial behavior was coded with a discrete facial action coding system. Maternal behavior was also coded. Measures of heart rate as well as short and long term variability were computed. Results revealed no differences in facial lability or in facial expressiveness between term and preterm infant. In addition, there were no differences in maternal behavior to either term or preterm. There were, however, reliable contingent relationships between facial expression of the infant and maternal behavior. In addition, there was a significant association between short term variability (vagal tone) and infant facial behavior.     

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 reaching behavior in low-risk preterm infants

This longitudinal study investigated the development of reaching behavior in the seated position in preterm infants at the ages of 5–7 months by analyzing kinematic variables (straightness and adjustment indexes, movement unit, mean and final velocities). The correlation between kinematic variables and grasping was verified. The participants were nine low-risk preterm infants with no cerebral lesions. Ten fullterm infants served as control. In both groups, kinematic variables remained unchanged over age, except for the adjustment index, which was higher at 6 months in the preterm group. Successful grasping increased in both groups over age and it was shown to be negatively correlated with mean velocity in the preterm infants. At the ages of 6 and 7 months, preterms showed lower mean and final velocities and higher adjustment index when compared with fullterms. The relative constancy in the kinematic variables suggests that, after having explored the action possibilities during the acquisition phase, the infants selected an adaptative pattern to perform the reaching movements. Slower movements and greater adjustments may be functional strategies of preterms to achieve successful grasps.     

Preterm infants' responses in early joint attention interactions

The joint attention behaviors of 46 preterm (25 low risk and 21 high risk) and 25 full-term infants at 6 months of age were compared in videotaped interactions with their mothers. The main objective of the study was to investigate whether preterm infants (of varying degrees of risk) and their mothers showed different joint attention behaviors (i.e., coordination of their attention to people and objects) than full-term infants and their mothers. Results revealed that the preterm infants, regardless of degree of risk, showed similar patterns of responding in joint attention interactions with their mothers as the full-term infants. The preterms' severity of early medical complications was related to the frequency with which reaching for toys occurred rather than the amount of time spent in episodes of joint engagement. In addition, the preterms moved their attention away from joint engagement more often than full-terms. There were no group differences for maternal joint attention behaviors.     

Attention and recognition memory in the 1st year of life: a longitudinal study of preterm and full-term infants

Several aspects of visual attention and their implications for recognition memory were examined in a longitudinal sample of full-term and preterm (birth weight < 1,750 g) infants seen at 5, 7, and 12 months of age. At all 3 ages, full-terms had shorter look durations, faster shift rates, less off-task behavior, and higher novelty scores than preterms. Both groups followed similar developmental trajectories, with older infants having shorter looks and more shifts. Infants were consistent in attentional style across problems of the same type, across problems that used different types of stimuli (faces and patterns), and across the familiarization and test phases of this paired-comparison design; there was also modest cross-age stability. Shorter looks and higher shift rates during familiarization were related to better recognition memory, with shift rate adding to prediction independently of either peak or mean look. These findings underscore the importance of attention to infant information processing.     

Effects of maternal attention-directing strategies on preterms' response to toys

The relationship between maternal attention-directing strategies in 12-month play interactions and infant response level was investigated for 40 preterm (subdivided into two risk groups) and 20 full-term infants. Mothers use of particular strategies (i.e., maintenance of infants' interests and use of verbal and nonverbal techniques that focus attention, were hypothesized to affect the various infant risk groups in different ways. Results indicated that mothers of preterms used different attention-directing strategies than mothers of full-terms. Mothers of preterms could be further differentiated by the severity of their infants' medical complications. These differences did not, however, adversely affect infant response level. Mothers across the three infant groups used strategies that facilitated infants' manipulation of toys. Discrepancies between the mothers of preterms and full-terms in their use of particular verbal and nonverbal techniques (e.g., questions, attention-directing gestures) can be explained in part by the relationship between the use of these techniques and the infants' developmental level.     

Two-month-olds' attention and affective response to maternal still face: a comparison between term and preterm infants in Taiwan

Maternal still face is a robust experimental procedure designed to examine infants’ sensitivity to social contingency and reactivity to its violation. To extend earlier research on the still-face effect on term infants in Western cultures, the present study compared Taiwanese term and preterm infants’ attention and affective response to and recovery from a modified maternal still-face procedure that used an additional still-face reengagement sequence at 2 months of age (corrected age for preterm infants). Infants’ gaze and facial affect were coded from videos. Results showed that preterm infants were as sensitive as term infants to the interruption to social contingency. Both groups of infants reacted with decreased gaze and positive affect across episodes, together with a decreased latency to gaze aversion and an increased latency to positive affect. Both term and preterm infants also demonstrated a W-shaped pattern of decline-followed-by-recovery in their latency to negative affect. However, compared to term infants, preterm infants became distressed faster and stayed in a negative affective state longer after the first exposure to maternal still face. Effects of prematurity on infant attention and affect regulation were discussed. Implications of preterm infants’ heightened affective negativity to mild stress for intervention studies were also addressed.     

Goal saliency boosts infants’ action prediction for human manual actions,but not for mechanical claws

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 perceptual–attentional explanation of gaze following in 3‐ and 6‐month‐olds

Two experiments were conducted with 3‐ and 6‐month‐olds using a standard gaze following procedure with targets to examine the possibility that perceptual–attentional constraints may affect young infants’ gaze following. In Experiment 1, either moving or stationary targets were positioned at 15° from the infants’ midline. In Experiment 2, stationary targets were positioned at either 25° or 40° from the infants’ midline. Gaze following was evaluated with three criteria. Infants made significantly more correct responses to the 15° stationary targets than all other response types combined. When targets were moving or further away, infants made significantly more correct than incorrect responses when they made a turn; however, they did not make significantly more correct responses across all trials. It is argued that the infants’ responses are indicative of perceptual–attention constraints operating where the adult head and eye turn shifts infants’ attention to the side but whether the infants then ‘gaze follow’ depends on the structure of the environment as well as the infants’ ability to disengage attention and initiate saccadic eye movements.     

From biological rhythms to social rhythms: Physiological precursors of mother-infant synchrony

Links between neonatal biological rhythms and the emergence of interaction rhythms were examined in 3 groups (N = 71): high-risk preterms (HR; birth weight <1,000 g), low-risk preterms (LR; birth weight =1,700-1,850 g), and full-term (FT) infants. Once a week for premature infants and on the 2nd day for FT infants, sleep-wake cyclicity was extracted from 4-hr observations and cardiac vagal tone was measured. At term age, infant orientation was tested with the Neonatal Behavior Assessment Scale. At 3 months, arousal modulation and emotion regulation were assessed, and mother-infant synchrony was computed from microanalysis of face-to-face interactions using time-series analysis. Sleep-wake amplitudes showed a developmental leap at 31 weeks gestation, followed by a shift in vagal tone at 34 weeks gestation. At term, differences among FT, LR, and HR infants were observed for biological rhythms in a linear-decline pattern. Sleep-wake cyclicity, vagal tone, newborn orientation, and arousal modulation were each uniquely predictive of mother-infant synchrony. The organization of physiological oscillators appears to lay the foundation for the infant's capacity to partake in a temporally matched social dialogue.     

Development of looking with head and eyes

Research into stabilization of gaze has concentrated on how the eyes counterrotate to compensate for head rotation. There is little information on how head movements function as an integral part of gaze stabilization. The head and eye coordination of six adults and six infants was tested under two conditions: tracking a moving target when the body was stationary; fixating a stationary target when the body was turning. Under each condition, both infants and adults turned their heads more than their eyes in stabilizing gaze. The infants were tested at 3-week intervals between the ages of 11 and 28 weeks. During this period, the precision with which head turning was coupled to their own or the target movement developed to near adult level, showing rapid growth between 11 and 16 weeks. However, the infants' ability to couple the eyes onto the target did not change over the tested period, remaining much less precise than the adults'. These findings have important implications for the assessment of abnormal gaze stabilization, which could facilitate the early diagnosis of perceptuomotor dysfunction.     

Dynamics of oralrespiratory coordination in full-term and preterm infants: II. Continuing effects at 3 months post term

Thirty-two infants participating in a longitudinal study of the effects of premature birth on sucking and breathing were tested at 3 months post term. They were assigned at a previous test to either a healthy full-term, healthy preterm, or high risk preterm group on the basis of birth weight, postconceptional age at birth, and perinatal medical status. Positive and negative sucking pressure as well as chest and abdominal breathing movements were recorded during nutritive sucking. The high risk preterms used a simpler and more stable pattern of coordination between sucking and breathing, were more likely to interrupt breathing at milk onset, and produced longer phase lags between positive and negative sucking pressure.