Infants born preterm and infants born full-term generate more selective leg joint movement during the scaffolded mobile task

Infants born very preterm (PT), prior to 32 weeks gestation, are at increased risk of developing cerebral palsy. Children with spastic cerebral palsy have impaired selective leg joint movement, which contributes to lifelong walking limitations. We investigated whether infants born PT generated more selective hip–knee joint movement (e.g., hip flexes as knee extends) while participating in a scaffolded mobile task. Infants born PT and infants born full-term (FT) at 4 months corrected age participated in a scaffolded mobile task for 2–3 consecutive days. The scaffolded mobile task required infants to raise their legs vertically over a virtual threshold. Three threshold heights (low, middle, and high) were used to test whether the middle and high heights encourage infants to move their legs more selectively. Fifteen infants born FT learned the task and showed more selective hip–knee movement at each of the three threshold heights on the day that they learned, compared with their baseline spontaneous kicking. Thirteen infants born PT learned the task and showed more selective hip–knee movement on their learning day, but only when the middle and high thresholds were used. The results show that the scaffolded mobile task effectively encouraged infants to generate more selective hip–knee joint movement.     

Infants born full term and preterm increase the height of anti-gravity leg movements during a kick-activated mobile task using a scaffolded task environment

Prior research supports that infants born very preterm (PT), compared with full term (FT), have early differences in rate of learning and motor control that may hinder their ability to learn challenging motor tasks. Four-month-old infants born FT (n = 18) and PT (n = 18) participated in an infant kick-activated mobile task that was scaffolded to motivate progressively higher kicks. We found the FT group learned the association between their leg movements and mobile activation on the second day, but the PT group learned the association on the third day. Both groups of infants increased the height of their kicks on the day they learned the task, compared with their spontaneous kicking height. These findings suggest that infants born PT have the ability to learn challenging motor tasks, such as kicking high, when participating in a task environment that uses scaffolding.     

Behavior of Mothers and Infants With and Without Down Syndrome During the Still‐Face Procedure

There has been limited study of how the constitutional characteristics of infants with Down syndrome (DS) influence the patterning of their relations with caregivers. To assess natural and perturbed interactions between infants with DS and their mothers, we tested ten 6‐month‐old infants with DS and 20 typically developing (TD) 4‐month‐old of similar mental age. Participants were videotaped with their mothers in a natural face‐to‐face interaction, a brief period when the mothers adopted a still‐face, and a subsequent reengagement phase. There was little to distinguish the infants in the initial phase of natural interaction, but the mothers of infants with DS were more likely to show assertive warmth, and unlike in the case of mothers of TD infants, high maternal directiveness tended to be associated with lower levels of infant looking and lack of fussing. During the still‐face episode, infants of both groups showed reduced looking and smiling, although infants with DS tended to show lower levels of fussing and fewer in this group showed fussing in the reengagement phase. Therefore DS infants were somewhat similar to TD infants of comparable mental age in being responsive to the still‐face procedure, but showed indications of group differences in intense emotional reactivity.     

Object exploration during the transition to sitting: A study of infants at heightened risk for autism spectrum disorder

Learning to sit promotes infants' object exploration because it offers increased access to objects and an improved position for exploration (e.g., ). Infants at heightened risk (HR) for autism spectrum disorder (ASD) exhibit delays in sitting and differences in object exploration. However, little is known about the association between sitting and object exploration among HR infants. We examined changes in object exploration as HR infants (N = 19) and comparison infants with no family history of ASD (Low Risk; LR; N = 23) gained experience sitting independently. Infants were observed monthly from 2.5 months until 1 month after the onset of independent sitting. At 12, 18, 24, and 36 months, infants completed standardized developmental assessments, and HR infants were assessed for ASD symptoms at 36 months. Although HR infants began sitting later than LR infants, both groups increased time spent grasping, shaking, banging, and mouthing objects as they gained sitting experience. Groups only differed in time spent actively mouthing objects, with LR infants showing a greater increase in active mouthing than HR infants. Findings suggest that HR infants experience a similar progression of object exploration across sitting development, but on a delayed time scale.     

Infant‐directed speech to infants at risk for dyslexia: A novel cross‐dyad design

When mothers speak to infants at risk for developmental dyslexia, they do not hyperarticulate vowels in their infant‐directed speech (IDS). Here, we used an innovative cross‐dyad design to investigate whether the absence of vowel hyperarticulation in IDS to at‐risk infants is a product of maternal infant‐directed behavior or of infants’ parent‐directed cues. Interactions between mothers and infants who were at risk or not at risk for dyslexia were recorded in three conditions: when mothers interacted with (a) their own infants, (b) infants who were not their own but of the same risk status, and (c) infants who were not their own and of the opposite risk status. This design revealed both infant and parent effects. Mothers of not‐at‐risk infants hyperarticulated vowels significantly more when speaking to not‐at‐risk than to at‐risk infants. In contrast, mothers of at‐risk infants hyperarticulated vowels significantly less than NAR mothers, and this was irrespective of infant status. Mothers of not‐at‐risk infants thus adjusted their IDS to the infant's risk status, while mothers of at‐risk infants did not. We suggest that IDS is determined reciprocally by characteristics of both partners in the dyad: Both infant and maternal factors are essential for the vowel hyperarticulation component of IDS.     

A multi-dimensional assessment of the health needs of homeless infants and pre-school children in Phoenix

The dual purpose of this study was to identify the comprehensive health needs of a selected group of homeless children in Phoenix, Arizona, and to utilize the findings in developing needed services. A non-random sample of 60 infants and pre-school children were given on-site physical, dental, developmental, behavioral, and nutritional assessments. The study included Medicaid's Early Periodic Screening, Diagnosis, and Treatment procedures, complete oral screening, the Denver Developmental and Denver Articulation Screening Test, the Pre-school Behavior Inventory, and parental interviews. Fifty-eight of the 60 children screened needed further evaluation, treatment, or followup services. The most significant problems included low hematocrit readings, inadequate immunizations, and untreated medical and dental problems specific to this age group. Also identified were developmental delays and potential behavior problems. It is imperative that aggressive outreach and followup services be developed to reach homeless children and to insure that needed interventions are provided.     

The Developmental Trajectory of Nonadjacent Dependency Learning

We investigated the developmental trajectory of nonadjacent dependency learning in an artificial language. Infants were exposed to 1 of 2 artificial languages with utterances of the form [aXc or bXd] (Grammar 1) or [aXd or bXc] (Grammar 2). In both languages, the grammaticality of an utterance depended on the relation between the 1 st and 3rd elements, whereas the intervening element varied freely. High variability of the middle element is known to contribute to perception of nonadjacent dependencies (Góomez, 2002), but the developmental trajectory of such learning is unknown. Experiment 1 replicated the study of Gómez with a younger age group and a more subtle variability manipulation. Twelve‐month‐olds failed to track nonadjacent dependencies under conditions tested here (Experiments 2a and 2b), but by 15 months, infants are beginning to track this structure (Experiment 3). Such learning has implications for understanding how infants might begin to acquire similar structure in natural language.     

Behavior of Infant Chimpanzees During the Night in the First 4 Months of Life: Smiling and Suckling in Relation to Behavioral State

This article reports the behavior of 3 newborn chimpanzees in the first 4 months of life, reared by their mothers and living in a community of 14 chimpanzees in a semi‐natural enriched environment. We focused on spontaneous activity during the night partly because sleeping behavior constitutes an essential part of the infants' activity. Observation during the night also had the advantage of keeping the influence of the mothers' activity as well as the environmental stimulation constant throughout the observation period. We report several interesting findings. Behavioral states defined through overt features such as open or closed eyes were variable during the night, with the rapid eye movement (REM) and non‐REM sleep patterns alternating much as they do in human infants. Although crying is one of the distinctive behavioral states in the case of human infants, the chimpanzee infants did not cry like humans. Suckling behavior was often accompanied by open eyes until the end of the first 2 months. Thereafter, suckling with the eyes closed became more prominent. Although there were no explicit stimuli, the newborns showed neonatal smiling with the eyes closed during REM sleep periods. However, neonatal smiling disappeared within the first 2 months and was replaced by social smiling with open eyes. Taken together, the results suggest a strong similarity between human infants and chimpanzee infants in terms of developmental changes in spontaneous activities at around 2 months of age.     

Online reach correction in 6- and 11-month-old infants

The current study investigated the development of online reach control. Six- and 11-month-old infants reached for a toy while their hand position was tracked. The toy either remained stationary (baseline trials) or unexpectedly displaced left- or rightward during the reach (perturbation trials). To obtain a measure of online reach correction, we compared reaches in the perturbation trials to reaches in baseline trials using autoregression analysis. Infants of both age groups adjusted their reach trajectories in the direction of the displacement. Moreover, we divided the reaching movements into movement units, defined as the submovements of a reach between local minima in hand speed. Eleven-month-old infants adjusted their reach within the span of a single movement unit; corrections in 6-month-olds spanned multiple movement units. These results suggest that the reach control system has a rudimentary replanning capacity by 6 months of age, which, with age, further develops to a more sophisticated online control mechanism for ongoing reaches.     

Typical and Atypical Development of Visual Attention in 3‐ to 9‐Month‐Old Infants

The interactions between attention and stimulus encoding in infancy were examined using heart rate (HR) and visual habituation measures. At 3, 6, and 9 months of age, infants (N = 119) were habituated to an adult face; longest look (LL) duration was measured as an indicator of encoding speed. Three groups were formed based on LL change from 3 to 9 months: Large Decrease, Small Decrease, and Increase. Using concurrent electrocardiograph recordings, attention was measured through the percentage of looking time in orienting, sustained attention, and attention termination. We partially replicated previous findings regarding developmental patterns of attention in these three groups, notably that these patterns were different for the Increase group. Looks away from the stimulus were also assessed in each attentional phase and, as predicted, HR acceleration phases showed less visual engagement than HR deceleration phases. We also found anomalous behavior for the LL Increase group. In general, this small but distinct group showed similarities at 3 months to the presumably more mature behavior of typical 9 month olds, but by 9 months, they behaved more like typical 3 month olds regarding some, but not all, cognitive measures. These results are discussed in the context of the development of endogenous attention.     

Dynamic changes in numerical acuity in 4-month-old infants

Preverbal infants represent the approximate numerosity of visual and auditory arrays: By 6 months old, they reliably discriminate eight dots or tones from 16 (a 1:2 ratio), but not eight from 12 (a 2:3 ratio). The precision of this approximate number sense improves gradually over childhood and into adulthood. However, less is known about numerical abilities in younger infants, and in particular, whether there is developmental change in the number sense in the first half year of life. Here, in four experiments, we measured numerical precision in 4-month-old infants (N = 128) using a visual habituation task comparable to that in studies of older infants. We found that 4-month-olds exhibited poorer numerical discrimination than the 6-month-olds tested in previous studies, dishabituating to a 1:4 change in numerical ratio, but not a 1:3 change. Like older infants, 4-month-olds’ numerical precision improved when they were provided with redundant visual and auditory input; when both visual and auditory information were present, 4-month-olds discriminated a 1:3 but not a 1:2 ratio. These results suggest that Approximate Number System precision develops in early infancy and may be sensitive to intersensory redundancy as early as four months of age.     

Neural mechanisms of language development in infancy

Understanding the neural processes underpinning individual differences in early language development is of increasing interest, as it is known to vary in typical development and to be quite heterogeneous in neurodevelopmental conditions. However, few studies to date have tested whether early brain measures are indicative of the developmental trajectory of language, as opposed to language outcomes at specific ages. We combined recordings from two longitudinal studies, including typically developing infants without a family history of autism, and infants with increased likelihood of developing autism (infant-siblings) (N = 191). Electroencephalograms (EEG) were recorded at 6 months, and behavioral assessments at 6, 12, 18, 24 and 36 months of age. Using a growth curve model, we tested whether absolute EEG spectral power at 6 months was associated with concurrent language abilities, and developmental change in language between 6 and 36 months. We found evidence of an association between 6-month alpha-band power and concurrent, but not developmental change in, expressive language ability in both infant-siblings and control infants. The observed association between 6-month alpha-band power and 6-month expressive language was not moderated by group status, suggesting some continuity in neural mechanisms.     

Push or Carry? Pragmatic Opportunities for Language Development in Strollers versus Backpacks

Strollers and backpacks are employed early, frequently, and throughout the first year, with parents overwhelmingly using strollers. However, because these transport modalities put infants in different proximities to caregivers, postures, and states of alertness, their use may translate to different opportunities that are of developmental consequence, particularly with regard to language. We used GoPro technology in a within‐subjects counterbalanced design to measure dyadic vocalizations in strollers and backpacks with 7‐ to 11‐month‐old infants. Parent‐infant dyads (N = 36) who regularly used both transport modes took two 8‐min walks in their own neighborhoods using their own carriers while wearing lightweight head‐mounted GoPros. There was significantly more parent speech, infant vocalizations, dyadic conversations, and infant‐initiated speech in backpacks, as well as more head motion consistent with visual scanning by infants. Backpacks appear to be a practical way to encourage more engaging, language‐enriched developmental opportunities in the critical first year.     

Complex Interrelations of Trait Vulnerabilities in Mothers and their Infants

Despite the developmental and clinical relevance of this area of inquiry, no studies have examined the interrelations of trait vulnerabilities in the affective, behavioral, and interpersonal domains between mothers and their infants. Thus, this study examined the interrelations of three trait vulnerabilities (i.e., negative affective intensity, impulsivity, and insecure attachment) between mothers and their 12‐ to 23‐month‐old infants, focusing in particular on the unique and interactive influence of these maternal trait vulnerabilities on the expression of and precursors to these traits in their infants. Mother–infant dyads (N = 101) completed several laboratory procedures, and mothers reported on their own and their infants' expressions of the trait vulnerabilities of interest. Findings from this study provide preliminary evidence for intergenerational relations between these traits and suggest that it is the confluence of trait vulnerabilities in mothers that relates to the early expression of some of these traits in infants.     

Development of Tactile Responses in Human Preterm and Full‐Term Infants From 30 to 40 Weeks Postconceptional Age

Maturation of tactile sensitivity prior to term was examined in 36 preterm and 13 full‐term infants using a fixed‐trial, habituation procedure. Each infant was presented with a series of 8 habituation (arm stroke), 2 novel (arm lift), and 2 recovery (arm stroke) stimulus trials while heart rate and body movements were recorded. Maturation was observed with a gradual increase in the magnitude of the stimulus‐elicited cardiac acceleration and cardiac‐movement coupling from 30 to 40 weeks postconceptional age. The majority of infants displayed habituation—an excitatory response (heart rate acceleration and body movement)—to the initial presentation of a tactile stimulus, response decline with repeated stimulations, and renewed response to a novel stimulus. A substantial number of infants (40%) failed to respond initially to the tactile stimulus, increased responding over several stimulus presentations, and failed to discriminate the presentation of a novel stimulus. We speculate that these differences in response patterns observed over all ages represent individual difference in the perception of stimulus intensity.     

Early childhood interventionists' perspectives on serving maltreated infants and toddlers

A 2003 amendment to the Child Abuse Prevention and Treatment Act (CAPTA) required states to create developmental screening programs for maltreated infants and toddlers. Programs authorized under Part C of the Individuals with Disabilities Education Act (IDEA) were directed to work with state and local child welfare authorities to develop the screening program. They were also to ensure that additional assessment and intervention was provided when needed. The degree to which this mandate has been implemented varies widely between state and local programs. Some early intervention experts and Part C program administrators have expressed concerns about providers' willingness to serve families referred from child welfare, but there has been no systematic research on this issue. The Professional Interventionist CAPTA Survey (PICS) is a newly developed measure of early childhood intervention providers' perceptions of their responsibilities under CAPTA. The first aim of this study was to conduct analysis of the PICS using a national sample of providers. This study also reports the perceptions of early childhood interventionists about their responsibilities under CAPTA and examines the relationship between worker characteristics and how they perceive these responsibilities. The PICS appears to be useful for examining early childhood intervention providers' responses to CAPTA.     

The Organization of Wariness of Heights in Experienced Crawlers

Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff ( Campos, Bertenthal, & Kermoian, 1992 ; Gibson & Walk, 1960 ). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these nonavoiders lack wariness of heights or whether they have a qualitatively different way of showing their wariness than do avoiders of the deep side. The current study addressed this question by measuring heart rate (HR) acceleration upon being lowered on the deep and shallow sides of the visual cliff, latency to crawl toward the mother, and tactile exploration of the cliff surface. Nonavoiders and avoiders had indistinguishable patterns of HR acceleration, showing greater HR acceleration when lowered onto the deep than when lowered onto the shallow side of the cliff. Nonavoiders also showed more tactile exploration and longer latencies than did a comparable group of infants tested on the shallow side. This study illustrates how the same emotion, wariness of heights, can be shown by qualitatively different behaviors, all serving the same function of protecting the individual from falling over a drop‐off.     

Role of Clinical Diagnosis and Medication Use in Effects of Maternal Depression on Infant‐Directed Speech

Infant‐directed (ID) speech was recorded from mothers as they interacted with their 4‐ to 12‐month‐old infants. Hierarchical regression analyses revealed that two variables, age of the mother and mother's diagnosed depression, independently accounted for significant proportions of the variance in the extent of change in fundamental frequency (ΔF0). Specifically, depressed mothers produced ID speech with smaller ΔF0 than did nondepressed mothers, and older mothers produced ID speech with larger ΔF0 than did younger mothers. Mothers who were taking antidepressant medication and who were diagnosed as being in at least partial remission produced ID speech with mean ΔF0 values that were comparable to those of nondepressed mothers. These results demonstrate explicit associations between major depressive disorder and an acoustic attribute of ID speech that is highly salient to young infants.     

The Quality of Spontaneous Movements of Preterm Infants: Associations with the Quality of Mother–Infant Interaction

The assessment of the quality of infants’ spontaneous movements is a diagnostic tool for the young nervous system. We examined whether it relates to the quality of the interactions between infants born preterm and their mothers. Thirty‐nine healthy infants born preterm (M_{age in weeks} = 14.59, SD = 2.21; 38.46% female) and their mothers participated in the study. Infants’ quality of spontaneous movements was assessed using the General Movement Assessment according to Prechtl (Prechtl, Early Human Development 1990, 23, 151). A new measurement was employed to evaluate the following aspects of the mother–infant interaction: maternal sensitivity in the motor modality (i.e., when touching, picking up, holding, and putting down the infant), maternal sensitivity in the modalities of vocalization and eye contact, and infants’ positive engagement. Several aspects of infants’ quality of movements were associated with maternal sensitivity in the motor modality and infants’ positive engagement, but not with maternal sensitivity in the modalities of vocalization and eye contact. These findings suggest that the quality of infants’ spontaneous movements may explain some of the variability in the interactions between infants born preterm and their mothers. The results also highlight the importance of differentiating between the modalities of mothers’ behavior when assessing their sensitivity. Implications for research and practice with families of preterm infants are discussed.     

Policy options: early intervention services for substance-exposed infants.

Substance-exposed infants, or babies that have been victims of their mothers' drug use during pregnancy, have reached substantial proportions. Currently, no comprehensive public policy exists to deal with these infants as they enter a society unprepared to respond to an issue increasingly fraught with substantial adverse economic, social, and political ramifications. In order to address the needs of this emerging sub-population, California's governor and state legislature must develop and adopt a concerted interagency policy which outlines: a) uniform criteria for local health care workers, social service agencies, and educators; b) consistent guidelines governing the exchange of information among a range of agencies, including hospitals, schools, and other public and private agencies; and c) increased prevention and early intervention services for these babies and their families. Addressing the needs of these infants requires a bold, comprehensive, interdisciplinary approach from the creators of public policy.