Assessment and stability of early learning abilities in preterm and full-term infants across the first two years of life

Relationship Between Prone Skills and Motor-Based Problem-Solving Abilities in Full-Term and Preterm Infants During the First 6 Months of Life

Motor experiences shape cognitive development in infancy, with the prone position being one such crucial motor experience in the first 6 months of life. Although the motor benefits of the prone position are well-documented, its influence on early cognitive abilities remains insufficiently explored. This study quantified the relationship between prone motor skills and motor-based problem-solving abilities in 48 full-term and preterm infants aged 3-6 months. Prone skills were assessed using the Alberta Infant Motor Scale's prone domain. The Assessment of Problem-Solving in Play was utilized to measure motor-based problem-solving by observing how motor actions were used to solve toys. Advanced prone motor skills were correlated with an increase in sophisticated exploration skills and a concurrent decline in lower order exploration skills in all infants, with correlations being stronger in preterm infants. Notably, a 1-point increase in prone skills was associated with a 1.3-point increase in total motor-based problem-solving abilities in all infants. Our findings provide preliminary evidence for the contribution of prone play to cognitive development in infants, prompting considerations for assessment and intervention strategies. Further research is needed to ascertain if the delayed acquisition of prone motor skills is indicative of poor early problem-solving abilities in preterm infants.

The impact of severity of motor delay, timing of task mastery, and START-play intervention on the development of means-end problem solving in young children

BACKGROUND

Children with motor delays are at increased risk for delayed means-end problem-solving (MEPS) performance.

OBJECTIVES

To evaluate children with motor delays: 1) the impact of motor delay severity and MEPS mastery timing on developmental trajectories of MEPS; and 2) the effectiveness of Sitting Together And Reaching To Play (START-Play) intervention for improving MEPS.

METHODS

This represents a secondary analysis from a multi-site randomized controlled trial, with blinded assessors and prospective registration. Children with mild or significant motor delays (n = 112, mean age=10.80, SD=2.59 months at baseline) were randomly assigned to START-Play or usual care early intervention (UC-EI) and assessed at five visits across one year using the Means-End Problem-Solving Assessment Tool that included three 30-second MEPS trials per visit. Task mastery occurred at the first visit the child achieved the highest level of performance in at least two of the three trials. Multilevel analyses evaluated trajectories of MEPS outcomes dependent upon the timing of MEPS mastery, motor delay severity, and intervention group.

RESULTS

At baseline, children with mild motor delays demonstrated better MEPS than children with significant delays, but this difference was only observed for children who achieved mastery late. Children with significant delays demonstrated greater improvements in MEPS in the post-intervention phase compared to children with mild delays. No MEPS differences were found between START-Play and UC-EI.

CONCLUSION

Motor delay severity and timing of task mastery impacted MEPS trajectories, whereas START-Play intervention did not impact MEPS for children with motor delays.

CLINICAL TRIALS REGISTRY IDENTIFIER

NCT02593825 (https://clinicaltrials.gov/ct2/show/NCT02593825).

Effect of a NICU to Home Physical Therapy Intervention on White Matter Trajectories, Motor Skills, and Problem-Solving Skills of Infants Born Very Preterm: A Case Series

Infants born very preterm (VPT; ≤29 weeks of gestation) are at high risk of developmental disabilities and abnormalities in neural white matter characteristics. Early physical therapy interventions such as Supporting Play Exploration and Early Development Intervention (SPEEDI2) are associated with improvements in developmental outcomes. Six VPT infants were enrolled in a randomised clinical trial of SPEEDI2 during the transition from the neonatal intensive care unit to home over four time points. Magnetic resonance imaging scans and fixel-based analysis were performed, and fibre density (FD), fibre cross-section (FC), and fibre density and cross-section values (FDC) were computed. Changes in white matter microstructure and macrostructure were positively correlated with cognitive, motor, and motor-based problem solving over time on developmental assessments. In all infants, the greatest increase in FD, FC, and FDC occurred between Visit 1 and 2 (mean chronological age: 2.68-6.22 months), suggesting that this is a potential window of time to optimally support adaptive development. Results warrant further studies with larger groups to formally compare the impact of intervention and disparity on neurodevelopmental outcomes in infants born VPT.

Infants born preterm demonstrate reduced task-specific exploration during the scaffolded kick-activated mobile task

This study quantified the spatial exploration of 13 infants born very and extremely preterm (PT) at 4 months corrected age as they learned that moving their feet vertically to cross a virtual threshold activated an infant kick-activated mobile and compared results to 15 infants born full-term (FT) from a previously published study. Spatial exploration was quantified using two general spatial exploration variables (exploration volume, exploration path), two task-specific spatial variables (duration of time in the task-specific region of interest, vertical variance of kicks), and one non-task-specific spatial variable (horizontal variance of kicks). The infants born PT, similar to FT, increased their general spatial exploration and duration in the region of interest and did not change the vertical and horizontal variances of kicks. However, the infants born PT, compared to FT, spent less time in the task-specific region of interest and had a greater non-task-specific horizontal variance throughout the task. This may indicate that infants born PT and FT exhibit similar general spatial exploration, but infants born PT exhibit less task-specific spatial exploration. Future research is necessary to determine the contribution of learning and motor abilities to the differences in task-specific exploration between infants born PT and FT.

A model for using developmental science to create effective early intervention programs and technologies to improve children's developmental outcomes

Children born with a variety of environmental or medical risk factors may exhibit delays in global development. Very often, such delays are identified at preschool or school age, when children are severely overdue for effective early interventions that can alleviate the delays. This chapter proposes a conceptual model of child development to inform the creation of interventions and rehabilitative technologies that can be provided very early in development, throughout the first year of life, to optimize children's future developmental outcomes. The model suggests that early sensorimotor skills are antecedent and foundational for future motor, cognitive, language, and social development. As an example, this chapter describes how children's early postural control and exploratory movements facilitate the development of future object exploration behaviors that provide enhanced opportunities for learning and advance children's motor, cognitive, language, and social development. An understanding of the developmental pathways in the model can enable the design of effective intervention programs and rehabilitative technologies that target sensorimotor skills in the first year of life with the goal of minimizing or ameliorating the delays that are typically identified at preschool or school age. Specific examples of early interventions and rehabilitative technologies that have effectively advanced children's motor and cognitive development by targeting early sensorimotor skills and behaviors are provided.

Infants exploring objects: A cascades perspective

Infants spend much of their time exploring objects (Herzberg et al., 2021), and object exploration is linked to learning and development in various domains (e.g., social, cognitive, motor). But how does exploration develop in the first place, and how, exactly, does exploration promote learning? One way to approach these process-oriented questions is with a developmental cascades perspective, which holds that new skills emerge from earlier-developing ones and that various interactions with people and objects accumulate over time to influence multiple domains of development (Masten & Cicchetti, 2010). In this chapter, we describe object exploration from a developmental cascades perspective. In Section 2, we describe typical and atypical trajectories of exploration behaviors, noting how these behaviors emerge from earlier-developing cognitive and motor skills. In Section 3, we discuss how object exploration opens the door for new types of learning opportunities. In Section 4, we discuss early experiences that may shape the development of object exploration. Altogether, we aim to convey that new developments in exploration skills are extensions of earlier-developing skills, and that seemingly insignificant exploratory behaviors (e.g., shaking a rattle) may result in numerous and varied consequences for the developing infant.

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.

Measuring Early Problem-Solving in Young Children with Motor Delays: A Validation Study

AIM

There is a lack of evidence-based tools for measuring problem-solving in young children with motor delays. The purpose of this study was to evaluate the construct validity and responsiveness of the Assessment of Problem-Solving in Play.

METHODS

125 young children (10.72, SD 2.62 months) with mild, moderate, and severe motor delays were assessed with the Bayley Scales of Infant and Toddler Development, Third Edition Cognitive Scale and the Assessment of Problem-Solving in Play up to 4 times over 12 months. The baseline and change over time assessment scores were compared.

RESULTS

The Assessment of Problem-Solving in Play was strongly, positively correlated with the Bayley Scales of Infant and Toddler Development, Third Edition Cognitive Scale raw scores at baseline (r=.83, p<.001) and for changes in scores across time (r=.64, p<.001). On average, participants demonstrated positive change in problem-solving scores across time. Participants with severe motor delay scored lower at baseline and changed less as compared to other participants.

CONCLUSIONS

Results provide evidence for the construct validity and responsiveness of the Assessment of Problem-Solving in Play scores in quantifying problem-solving in young children with motor delays 7-27 months of age.

A Novel Means-End Problem-Solving Assessment Tool for Early Intervention: Evaluation of Validity, Reliability, and Sensitivity

PURPOSE

To evaluate validity, reliability, and sensitivity of the novel Means-End Problem-Solving Assessment Tool (MEPSAT).

METHODS

Children with typical development and those with motor delay were assessed throughout the first 2 years of life using the MEPSAT. MEPSAT scores were validated against the cognitive and motor subscales of the Bayley Scales of Development. Intra- and interrater reliability, developmental trends, and differences among groups were evaluated.

RESULTS

Changes in MEPSAT scores positively related to changes in Bayley scores across time for both groups of children. Strong intra- and interrater reliability was observed for MEPSAT scoring across all children. The MEPSAT was sensitive to identify change across time and differences in problem-solving among children with varying levels of motor delay.

CONCLUSIONS

The MEPSAT is supported by validity and reliability evidence and is a simple tool for screening early problem-solving delays and evaluating change across time in children with a range of developmental abilities. What this adds to the evidence: The novel MEPSAT is supported by validity and reliability evidence. It is sensitive to detect problem-solving differences among young children with varying motor ability and to capture changes in problem-solving across time. It requires minimal equipment and time to administer and score and, thus, is a promising tool for clinicians to screen for early problem-solving delays or to track intervention progress in young children with or at risk for problem-solving delays.

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.

Toward Predicting Infant Developmental Outcomes From Day-Long Inertial Motion Recordings

As improvements in medicine lower infant mortality rates, more infants with neuromotor challenges survive past birth. The motor, social, and cognitive development of these infants are closely interrelated, and challenges in any of these areas can lead to developmental differences. Thus, analyzing one of these domains - the motion of young infants - can yield insights on developmental progress to help identify individuals who would benefit most from early interventions. In the presented data collection, we gathered day-long inertial motion recordings from N = 12 typically developing (TD) infants and N = 24 infants who were classified as at risk for developmental delays (AR) due to complications at or before birth. As a first research step, we used simple machine learning methods (decision trees, k-nearest neighbors, and support vector machines) to classify infants as TD or AR based on their movement recordings and demographic data. Our next aim was to predict future outcomes for the AR infants using the same simple classifiers trained from the same movement recordings and demographic data. We achieved a 94.4% overall accuracy in classifying infants as TD or AR, and an 89.5% overall accuracy predicting future outcomes for the AR infants. The addition of inertial data was much more important to producing accurate future predictions than identification of current status. This work is an important step toward helping stakeholders to monitor the developmental progress of AR infants and identify infants who may be at the greatest risk for ongoing developmental challenges.

Developmental Dimensions in Preterm Infants During the 1st Year of Life: The Influence of Severity of Prematurity and Maternal Generalized Anxiety

BACKGROUND

The literature has recognized premature birth as a risk factor for infant development and maternal anxiety. This study investigated the impact of the severity of birth weight, as well as of maternal anxiety at 3 months of infants' corrected age, on infants' outcomes during the 1st year postpartum. Moreover, it described the longitudinal trajectories of developmental outcomes, additionally exploring the impact of anxiety.

METHODS

The study compared 147 mothers and their 147 newborns, differentiated in 25 Extremely Low Birth Weight (ELBW), 41 Very Low Birth Weight (VLBW), and 81 Full-Term (FT) infants. At 3, 9, and 12 months (corrected age in the case of preterm infants) the level of infants' development was investigated according to the 5 quotients (Locomotor, Personal and Social, Hearing and Language, Eye-hand Co-ordination and Performance) of the Griffiths Mental Development Scales (GMDS-R). During the assessment of 3 months, mothers fulfilled Penn State Worry Questionnaire (PSWQ) to evaluate the presence of generalized anxiety.

RESULTS

Among the 5 GMDS-R quotients, significant effect of severity of birth weight emerged only for Performance quotient: preterm infants (ELBW at 3 months; VLBW at 12 months) showed lower scores than FT ones. Moreover, this quotient decreased from 3 to 9 and to 12 months for VLBW and FT infants, while it was stable for ELBW ones. A significant interaction between severity of birth weight and maternal anxiety emerged for Hearing and Language and Locomotor quotients. In the first case, scores for ELBW infants, independently from maternal anxiety, decreased from 9 to 12 months. The same results emerged for VLBW infants, in the case of non-anxious mothers. Regarding Locomotor quotient, mean scores decreased from 3 to 9 and to 12 months for all groups in the case of non-anxious mothers. Conversely, when mothers were anxious, this decrease emerged only for VLBW infants. Lastly, ELBW, VLBW and FT showed difference in the growth and slope of the trajectories of different quotients.

CONCLUSION

The severity of birth weight for preterm infants, also in interaction with maternal anxiety, had significant and specific impact on different dimensions of infants' development. Clinical implications of these results underline the need for individualized interventions.

Psychometric Properties of Assessments of Cognition in Infants With Cerebral Palsy or Motor Impairment: A Systematic Review

Objective

Approximately 50% of people with cerebral palsy have a cognitive impairment. However, many tools used to assess cognition in infants require almost normal fine motor ability, and thus may not accurately reflect cognitive abilities of infants with cerebral palsy or other motor impairments. This systematic review aimed to evaluate the psychometric properties of cognitive assessment tools for infants aged 0-24 months with motor impairments and to make recommendations about the most appropriate cognitive assessment tools for the purpose of discrimination, prediction, and evaluation.

Method

A systematic review was conducted. CINAHL, Embase, ERIC, Medline, PsycINFO, and SCOPUS databases were searched to identify studies reporting on 1 or more psychometric properties of a standardized cognitive assessment tool or questionnaire in a sample/subsample of infants with motor impairment. Of the 4,480 articles reviewed, 9 assessment tools were identified in 20 publications, which met our inclusion criteria. Articles were appraised using the COnsensus-based Standards for the selection of health Measurement INstruments to assess study rigor. The GRADE framework was applied to develop recommendations for clinical practice.

Results

The Mayes Motor-Free Compilation, Fagan Test of Infant Intelligence, and Bayley-III Low Motor/Vision have predictive and/or discriminative utility in this population. The Mullen Scales of Early Learning was the only tool with psychometric research available examining responsivity to change.

Conclusions

Assessment tools with low-motor/motor-free accommodations have greater accuracy in estimating cognitive abilities of infants with motor impairment than conventional norm-referenced tests. There, however, remains a significant paucity of research in this area.

Feasibility and Effectiveness of Intervention With the Playskin Lift Exoskeletal Garment for Infants at Risk

BACKGROUND

Infants born preterm and/or with brain injury often exhibit delays in the development of reaching and object exploration, increasing their risk of associated delays in cognitive development.

OBJECTIVE

The objective of this study was to longitudinally evaluate feasibility of use of the novel Playskin Lift exoskeletal garment (Playskin; developed and trademarked by Dr. Lobo's Super Suits FUNctional Fashion and Wearable Technology Program at the University of Delaware, Newark, DE, USA), the assistive and rehabilitative effects of intervention with the garment on reaching and object exploration ability, and to relate changes in reaching and object exploration to changes in cognition during intervention for infants at risk for developmental delays.

DESIGN

A multiple baseline single-case design with 1- to 2-month Baseline, 4-month Intervention, and 1-month Postintervention phases was implemented.

METHODS

Ten infants born preterm and/or with brain injury, mean [SD] age 2.2 [1.3] months at the beginning of the study, were assessed biweekly throughout the study both with and without the Playskin Lift. Assessments included a Reaching Assessment and the cognitive subscale of the Bayley Scales of Infant and Toddler Development. Reaching and object exploration behaviors were coded from videos of the Reaching Assessment. Results were analyzed using multilevel modeling in SAS.

RESULTS

The Playskin Lift improved infants' reaching ability, hand orientation for grasp and object exploration, and multimodal object exploration when worn within sessions, especially during the Intervention phase. The garment also improved independent reaching and object exploration across time during the Intervention phase, with retention of gains in the Postintervention phase. Improvement in reaching ability was positively related to changes in cognitive outcomes during the Intervention phase.

LIMITATIONS

Limitations included modest sample size and the potential confounds of development and experience with time.

CONCLUSIONS

The Playskin Lift can serve as a feasible, effective, and accessible assistive and rehabilitative device to advance reaching, object exploration, and cognition for infants at risk for future delays.

Means-end problem solving in infancy: Development, emergence of intentionality, and transfer of knowledge

Behaviors and performance of 23 typically developing infants were assessed longitudinally at 6, 9, 12, 18, and 24 months in two means-end tasks: pulling a towel or rotating a turntable to obtain a supported object. With age, infants performed more goal-directed behaviors, leading to increased problem-solving success. Intentionality emerged earlier in the towel task than in the turntable task (6.9 vs. 10.8 months). Potential knowledge transfer between the tasks was first observed at 9 months. This study provides insight into the development of means-end learning, the emergence of intentionality, and potential transfer of knowledge in tasks involving a similar concept (support) but requiring different modes of action for success (pulling vs. rotating).

What do recent human studies tell us about the association between anaesthesia in young children and neurodevelopmental outcomes?

Anaesthetic and sedative drugs transiently disrupt normal neural activity to facilitate healthcare procedures in children, but they can also cause long-term brain injury in experimental animal models. The US Food and Drug Administration (FDA) has recently advised that repeated or lengthy exposures to anaesthetic and sedative drugs prior to 3 yr of age have the potential to harm the development of children's brains and added warnings to these drug labels. Paediatric anaesthesia toxicity could represent a significant public health issue, and concern about this potential injury in children has become an important issue for families, paediatric clinicians and healthcare regulators. Since late 2015, important new data from five major clinical studies have been published. This narrative review aims to provide a brief overview of the preclinical and clinical literature, including a comprehensive review of these recent additions to the human literature. We integrate these new data with prior studies to provide further insights into how these clinical findings can be applied to children.

High-risk follow-up: Early intervention and rehabilitation

Early detection of childhood disability is possible using clinically available tools and procedures. Early detection of disability enables early intervention that maximizes the child's outcome, prevents the onset of complications, and supports parents. In this chapter, first we summarize the best-available tools for accurately predicting major childhood disabilities early, including autism spectrum disorder, cerebral palsy, developmental coordination disorder, fetal alcohol spectrum disorder, intellectual disability, hearing impairment, and visual impairment. Second, we provide an overview of the preclinical and clinical evidence for inducing neuroplasticity following brain injury. Third, we describe and appraise the evidence base for: (a) training-based interventions that induce neuroplasticity, (b) rehabilitation interventions not focused on inducing neuroplasticity, (c) complementary and alternative interventions, (d) environmental enrichment interventions in the neonatal intensive care and community settings, and (e) parent-child interaction interventions in the neonatal intensive care and community settings. Fourth, we explore emergent treatment options at clinical trial, designed to induce brain repair following injury. In conclusion, early diagnosis enables early intervention, which improves child and parent outcomes. We now know which interventions provide the biggest gains and the information can be used to help inform parental decision making when designing treatment plans for their children.

Differences in means-end exploration between infants at risk for autism and typically developing infants in the first 15 months of life

Our study compared means-end exploration in infants at risk (AR) for autism and typically developing (TD) infants using a nested box paradigm. Sixteen AR and 16 TD infants were observed at 9, 12, and 15 months with follow-up at 18 and 24 months. We collected video data on three tasks involving retrieval of a small toy by opening (a) an opaque box, (b) a transparent box, and (c) two nested boxes. Dependent variables included hand bias, time to completion, bilateral hand use, problem-solving strategies used, and tester assistance required. There were no group differences in terms of hand biases. Compared to TD infants, AR infants had lower bilateral hand use, poor problem solving skills, and required greater assistance. Both groups demonstrated age-related improvements in motor and cognitive skills. Means-end exploration provides a window into the bilateral coordination and motor planning/problem-solving abilities of young infants at risk for autism. Lastly, object retrieval tasks could serve as important learning contexts for at-risk infants.

Prematurity may negatively impact means-end problem solving across the first two years of life

Preterm infants are at risk for delays in motor, perceptual, and cognitive development. While research has shown preterm infants may exhibit learning delays in the first months of life, these delays are commonly under-diagnosed. The purpose of this study was to longitudinally evaluate behavioral performance and learning in two means-end problem-solving tasks for 30 infants born preterm (PT) and 23 born full-term (FT). Infants were assessed at 6, 9, 12, 18, and 24 months-old in tasks that required towel pulling or turntable rotation to obtain a distant object. PT infants performed more non-goal-directed and less goal-directed behavior than FT infants throughout the study, resulting in a lower success rate among PT infants. PT infants showed delayed emergence of intentionality (prevalence of goal-directed behaviors) compared to FT infants in both tasks. Amount and variability of behavioral performance significantly correlated with task success differentially across age. The learning differences documented between PT and FT infants suggest means-end problem-solving tasks may be useful for the early detection of learning delays. The identification of behaviors associated with learning and success across age may be used to guide interventions aimed at advancing early learning for infants at risk.

Sitting Together And Reaching To Play (START-Play): Protocol for a Multisite Randomized Controlled Efficacy Trial on Intervention for Infants With Neuromotor Disorders

BACKGROUND

There is limited research examining the efficacy of early physical therapy on infants with neuromotor dysfunction. In addition, most early motor interventions have not been directly linked to learning, despite the clear association between motor activity and cognition during infancy.

OBJECTIVE

The aim of this project is to evaluate the efficacy of Sitting Together And Reaching To Play (START-Play), an intervention designed to target sitting, reaching, and motor-based problem solving to advance global development in infants with motor delays or neuromotor dysfunction.

DESIGN

This study is a longitudinal multisite randomized controlled trial. Infants in the START-Play group are compared to infants receiving usual care in early intervention (EI).

SETTING

The research takes place in homes in Pennsylvania, Delaware, Washington, and Virginia.

PARTICIPANTS

There will be 140 infants with neuromotor dysfunction participating, beginning between 7 to 16 months of age. Infants will have motor delays and emerging sitting skill.

INTERVENTION

START-Play provides individualized twice-weekly home intervention for 12 weeks with families to enhance cognition through sitting, reaching, and problem-solving activities for infants. Ten interventionists provide the intervention, with each child assigned 1 therapist.

MEASUREMENTS

The primary outcome measure is the Bayley III Scales of Infant Development. Secondary measures include change in the Early Problem Solving Indicator, change in the Gross Motor Function Measure, and change in the type and duration of toy contacts during reaching. Additional measures include sitting posture control and parent-child interaction.

LIMITATIONS

Limitations include variability in usual EI care and the lack of blinding for interventionists and families.

CONCLUSIONS

This study describes usual care in EI across 4 US regions and compares outcomes of the START-Play intervention to usual care.

Prediction of three year outcomes using the Bayley-III for surgical, cardiac and healthy Australian infants at one year of age

BACKGROUND

Previous predictive research has predominantly focussed on infants who are preterm, low birth weight, who have a specific condition or who have undergone a specific procedure.

AIM

This study investigated the ability of outcomes at one year of age to predict outcomes at three years using the Bayley-III for infants who have undergone early major cardiac surgery (CS) or non-cardiac (NC) surgery and their healthy peers.

STUDY DESIGN

Participants who were part of the Development After Infant Surgery (DAISy) study who had complete Bayley-III assessments at one and three years of age were included in the analyses. This included 103 infants who had undergone CS, 158 who had NC surgery and 160 controls.

RESULTS

Bayley-III outcomes at one, although statistically significantly associated with three year outcomes in all domains were weak predictors of those outcomes for CS, NC surgical and healthy infants. Specificity for three year outcomes was good for cognitive, receptive language and fine motor domains for infants who had undergone CS and NC surgery. Sensitivity for <-1 SD at three years was poor for cognitive, expressive and receptive language, and fine motor outcomes for CS and NC surgical participants.

CONCLUSION

It remains difficult to predict how performance at one year on the Bayley-IIII predicts performance at three on the Bayley-III for infants who have undergone early major CS or NC surgery and for healthy Australian infants.

Cognition-Action Trade-Offs Reflect Organization of Attention in Infancy

This chapter discusses what cognition-action trade-offs in infancy reveal about the organization and developmental trajectory of attention. We focus on internal attention because this aspect is most relevant to the immediate concerns of infancy, such as fluctuating levels of expertise, balancing multiple taxing skills simultaneously, learning how to control attention under variable conditions, and coordinating distinct psychological domains. Cognition-action trade-offs observed across the life span include perseveration during skill emergence, errors and inefficient strategies during decision making, and the allocation of resources when attention is taxed. An embodied cognitive-load account interprets these behavioral patterns as a result of limited attentional resources allocated across simultaneous, taxing task demands. For populations where motor errors could be costly, like infants and the elderly, attention is typically devoted to motor demands with errors occurring in the cognitive domain. In contrast, healthy young adults tend to preserve their cognitive performance by modifying their actions.

Infants Born Preterm Demonstrate Impaired Exploration of Their Bodies and Surfaces Throughout the First 2 Years of Life

BACKGROUND

Non-object-oriented exploratory behaviors infants perform with their bodies and surfaces have been proposed to be key precursors of infants' object exploration, early learning, and future cognitive development. Little is known about the developmental trajectories of these behaviors, especially for infants born preterm.

OBJECTIVE

The purpose of the study was to longitudinally compare non-object-oriented exploratory behaviors performed by full-term and preterm infants.

DESIGN

The study followed 24 full-term and 30 preterm infants (6 with significant brain injury) performing non-object-oriented exploratory behaviors in prone, supine, and sitting from birth through 24 months.

METHODS

Infants were observed without objects or direct social interaction for 3 minutes in prone and supine (0 through 9 months) and in sitting (3 through 24 months). Behavioral coding produced data that were analyzed using hierarchical linear modeling. Developmental trajectories of behaviors were compared among full-term infants, preterm infants without significant brain injury, and preterm infants with significant brain injury.

RESULTS

Compared to full-term peers, preterm infants showed poorer postural control (less head lifting in prone), midline behavior (holding the head in midline, holding both hands in midline), hand-to-mouth and visual-motor behaviors against gravity, and more asymmetrical one-handed fisting. Preterm infants performed fewer bouts of non-object-oriented exploratory behaviors, and their behaviors were less variable with fewer combinations.

LIMITATIONS

There was a limited sample of infants born preterm with significant brain injury.

CONCLUSIONS

Non-object-oriented exploratory behaviors are important for early perceptual-motor development. Key differences were noted in these behaviors for infants born preterm. These differences may lead to impaired reaching, object exploration, and cognition. Early intervention programs should utilize assessments and interventions that target these very early non-object-oriented exploratory behaviors.

The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm

OBJECTIVE

To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm.

STUDY DESIGN

Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age.

RESULTS

Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments.

CONCLUSION

In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy.

Coupling Timing of Interventions With Dose to Optimize Plasticity and Participation in Pediatric Neurologic Populations

PURPOSE

The purpose of this article is to propose that coupling of timing of interventions with dosing of interventions optimizes plasticity and participation in pediatric neurologic conditions, specifically cerebral palsy. Dosing includes frequency, intensity, time per session, and type of intervention. Interventions focus on body structures and function and activity and participation, and both are explored. Known parameters for promoting bone, muscle, and brain plasticity and evidence supporting critical periods of growth during development are reviewed. Although parameters for dosing participation are not yet established, emerging evidence suggests that participation at high intensities has the potential for change. Participation interventions may provide an additional avenue to promote change through the life span. Recommendations for research and clinical practice are presented to stimulate discussions and innovations in research and practice.

Coordinated movement is influenced by prenatal light experience in bobwhite quail chicks (Colinus virginianus)

Sensory-motor development begins early during embryogenesis and is influenced by sensory experience. Little is known about the prenatal factors that influence the development of motor coordination. Here we investigated whether and to what extent prenatal light experience can influence the development of motor coordination in bobwhite quail hatchlings. Quail embryos were incubated under four light conditions: no light (dark), 2h of total light (2HR), 6h of total light (6HR), and diffused sunlight (controls). Hatchlings were video recording walking down a runway at three developmental ages (12, 24, and 48h). Videos were assessed for forward locomotion, a measurement of motor coordination, falls, a measurement of motor instability, and motivation to complete the task. We anticipated a linear decline of coordination with a reduction in prenatal light experience and improved coordination with age. Furthermore, as motor coordination becomes more laborious we anticipated motivation to complete the task would decline. However, our findings revealed hatchlings did not uniformly improve with age as expected, nor did the reduction of light result in a linear reduction in motor coordination. Instead, we found a more complex relationship with 6HR and 2HR hatchlings showing distinct patterns of stability and instability. Similarly, we found a reduction in motivation within the 6HR light condition. It appears that prenatal light exposure influences the development of postnatal motor coordination and we discuss these finding in light of neurodevelopmental processes influenced by light experience.

Influência de fatores de risco sobre o desenvolvimento da linguagem e contribuições da estimulação precoce: revisão integrativa da literatura

RESUMO O objetivo do estudo foi identificar evidências na literatura a respeito da influência dos fatores de risco sobre o desenvolvimento da linguagem da criança e as contribuições da estimulação precoce. Trata-se de uma revisão integrativa, que utilizou as bases de dados Lilacs, PubMed e SciELO e os descritores: linguagem infantil, fatores de risco, prematuro, criança pós-termo, índice de Apgar, estimulação precoce. A partir dos achados, extraíram-se os seguintes dados: autores, ano de publicação, objetivo, desenho do estudo, participantes e critérios, variáveis estudadas, principais achados. Para a organização e análise foi utilizada a técnica de Análise de Conteúdo do tipo temática. Foram identificados 1.421 artigos, 29 atenderam os critérios de inclusão. Os estudos foram categorizados por resultados afins; A maioria dos artigos selecionados trata do efeito da prematuridade sobre o desenvolvimento da linguagem. Quatro estudos investigaram a associação entre fatores de risco e problemas no desenvolvimento da linguagem. Um dos estudos avaliou crianças em idade escolar e associou valores de Apgar com DEL. Foi unanime a recomendação acerca do acompanhamento e intervenção precoce. Conclui-se que os fatores de risco elencados influenciam negativamente no desenvolvimento da linguagem. Reforça-se a recomendação do atendimento precoce e qualificado dessas crianças, evitando e/ou minimizando alterações futuras.

Implicit and explicit motor sequence learning in children born very preterm

BACKGROUND

Motor skills can be learned explicitly (dependent on working memory (WM)) or implicitly (relatively independent of WM). Children born very preterm (VPT) often have working memory deficits. Explicit learning may be compromised in these children.

AIMS

This study investigated implicit and explicit motor learning and the role of working memory in VPT children and controls.

METHODS

Three groups (6-9 years) participated: 20 VPT children with motor problems, 20 VPT children without motor problems, and 20 controls. A nine button sequence was learned implicitly (pressing the lighted button as quickly as possible) and explicitly (discovering the sequence via trial-and-error).

RESULTS

Children learned implicitly and explicitly, evidenced by decreased movement duration of the sequence over time. In the explicit condition, children also reduced the number of errors over time. Controls made more errors than VPT children without motor problems. Visual WM had positive effects on both explicit and implicit performance.

CONCLUSION

VPT birth and low motor proficiency did not negatively affect implicit or explicit learning. Visual WM was positively related to both implicit and explicit performance, but did not influence learning curves. These findings question the theoretical difference between implicit and explicit learning and the proposed role of visual WM therein.

Habituation as Parameter for Prediction of Mental Development in Healthy Preterm Infants: An Electrophysiological Pilot Study

The aim of this prospective pilot study was to evaluate the predictive value of discrimination and habituation, which was measured by mismatch negativity in 17 healthy very preterm (mean gestational age 27.4 weeks; range 25.0-31.3) and 16 term (mean gestational age 40.3 weeks; range 37.9-41.7) born infants at term equivalent age. Developmental outcome was measured by Bayley Scales of Infant Development-I in 13 preterm and 13 term-born children at a mean age of 21.7 months (±2.18) and 18.5 months (±1.9), respectively. No differences in amplitude and latency of the mismatch negativity were found between both groups at term equivalent age. Within the preterm group habituation capacity was positively correlated with the Mental Developmental Index (r = .654, P = .008) and Performance Developmental Index (r = .482, P = .048) at 21 months. Early learning capability, as measured by habituation, may be associated with a better prognosis for early mental development in healthy preterm infants.

Object engagement and manipulation in extremely preterm and full term infants at 6 months of age

Delays in the motor domain have been frequently observed in preterm children, especially those born at an extremely low gestational age (ELGA;<28 weeks GA). However, early motor exploration has received relatively little attention despite its relevance for object knowledge and its impact on cognitive and language development. The present study aimed at comparing early object exploration in 20 ELGA and 20 full-term (FT) infants at 6 months of age during a 5-minute mother-infant play interaction. Object engagement (visual vs manual), visual object engagement (no act vs reach), manual object engagement (passive vs active), and active object manipulation (mouthing, transferring, banging, turn/rotating, shaking, fingering) were analyzed. Moreover, the Griffiths Mental Development Scales 0-2 years (1996) were administered to the infants. Relative to FT peers, ELGA infants spent more time in visual engagement, and less time in manual engagement, active manipulation, mouthing, and turning/rotating. Moreover, they had lower scores on general psychomotor development, eye & hand coordination, and performance abilities. Close relationships emerged between manual object engagement and psychomotor development. Clinical implications of these results in terms of early evaluation of action schemes in ELGA infants and the provision of intervention programs for supporting these abilities are discussed.

Learning Disabilities in Extremely Low Birth Weight Children and Neurodevelopmental Profiles at Preschool Age

At school age extremely low birth weight (ELBW) and extremely low gestational age (ELGAN) children are more likely to show Learning Disabilities (LDs) and difficulties in emotional regulation. The aim of this study was to investigate the incidence of LDs at school age and to detect neurodevelopmental indicators of risk for LDs at preschool ages in a cohort of ELBW/ELGAN children with broadly average intelligence. All consecutively newborns 2001-2006 admitted to the same Institution entered the study. Inclusion criteria were BW < 1000 g and/or GA < 28 weeks. Exclusion criteria were severe cerebral injuries, neurosensory disabilities, genetic abnormalities, and/or a Developmental Quotient below normal limits (< 1 SD) at 6 years. The presence of learning disabilities at school age was investigated through a parent-report questionnaire at children's age range 9-10 years. Neurodevelopmental profiles were assessed through the Griffiths Mental Development Scales at 1 and 2 years of corrected age and at 3, 4, 5, and 6 years of chronological age and were analyzed comparing two groups of children: those with LDs and those without. At school age 24 on 102 (23.5%) of our ELBW/ELGAN children met criteria for LDs in one or more areas, with 70.8% comorbidity with emotional/attention difficulties. Children with LDs scored significantly lower in the Griffiths Locomotor and Language subscales at 2 years of corrected age and in the Personal-social, Performance and Practical Reasoning subscales at 5 years of chronological age. Our findings suggest that, among the early developmental indicators of adverse school outcome, there is a poor motor experimentation, language delay, and personal-social immaturity. Cognitive rigidity and poor ability to manage practical situations also affect academic attainment. Timely detection of these early indicators of risk is crucial to assist the transition to school.

Playskin Lift: Development and Initial Testing of an Exoskeletal Garment to Assist Upper Extremity Mobility and Function

BACKGROUND

A person's ability to move his or her arms against gravity is important for independent performance of critical activities of daily living and for exploration that facilitates early cognitive, language, social, and perceptual-motor development. Children with a variety of diagnoses have difficulty moving their arms against gravity.

OBJECTIVE

The purpose of this technical report is to detail the design process and initial testing of a novel exoskeletal garment, the Playskin Lift, that assists and encourages children to lift their arms against gravity.

DESIGN

This report details the design theory and process, the device, and the results of field testing with a toddler with impaired upper extremity function due to arthrogryposis multiplex congenita.

RESULTS

The Playskin Lift is an inexpensive (<$30 material costs), easy to use (5/5 rating), comfortable (5/5 rating), and attractive (4/5 rating) device. While wearing the device, the child was able to contact objects more often throughout an increased play space, to look at toys more while contacting them, and to perform more complex interactions with toys.

LIMITATIONS

This report details initial testing with one child. Future testing with more participants is recommended.

CONCLUSIONS

These results suggest that by considering the broad needs of users, including cost, accessibility, comfort, aesthetics, and function, we can design inexpensive devices that families and clinicians can potentially fabricate in their own communities to improve function, participation, exploration, and learning for children with disabilities.

Early communicative behaviors and their relationship to motor skills in extremely preterm infants

Despite the predictive value of early spontaneous communication for identifying risk for later language concerns, very little research has focused on these behaviors in extremely low-gestational-age infants (ELGA<28 weeks) or on their relationship with motor development. In this study, communicative behaviors (gestures, vocal utterances and their coordination) were evaluated during mother-infant play interactions in 20 ELGA infants and 20 full-term infants (FT) at 12 months (corrected age for ELGA infants). Relationships between gestures and motor skills, evaluated using the Bayley-III Scales were also examined. ELGA infants, compared with FT infants, showed less advanced communicative, motor, and cognitive skills. Giving and representational gestures were produced at a lower rate by ELGA infants. In addition, pointing gestures and words were produced by a lower percentage of ELGA infants. Significant positive correlations between gestures (pointing and representational gestures) and fine motor skills were found in the ELGA group. We discuss the relevance of examining spontaneous communicative behaviors and motor skills as potential indices of early development that may be useful for clinical assessment and intervention with ELGA infants.

Technology for Children With Brain Injury and Motor Disability: Executive Summary From Research Summit IV

Advances in technology show promise as tools to optimize functional mobility, independence, and participation in infants and children with motor disability due to brain injury. Although technologies are often used in adult rehabilitation, these have not been widely applied to rehabilitation of infants and children. In October 2015, the Academy of Pediatric Physical Therapy sponsored Research Summit IV, "Innovations in Technology for Children With Brain Insults: Maximizing Outcomes." The summit included pediatric physical therapist researchers, experts from other scientific fields, funding agencies, and consumers. Participants identified challenges in implementing technology in pediatric rehabilitation including accessibility, affordability, managing large data sets, and identifying relevant data elements. Participants identified 4 key areas for technology development: to determine (1) thresholds for learning, (2) appropriate transfer to independence, (3) optimal measurement of subtle changes, and (4) how to adapt to growth and changing abilities.

Neurobehavioral development prior to term-age of preterm infants and acute stressful events during neonatal hospitalization

BACKGROUND

Neonatal Intensive Care Units (NICUs) protect preterm infants; otherwise, this is a stressful environment including painful stimuli.

AIMS

To compare early neurobehavioral development prior to term-age in preterm infants at 34-36weeks of post-conceptional age in different gestational ages, and to examine the effects of prematurity level and acute stressful events during NICU hospitalization on neurobehavioral development.

STUDY DESIGN

Cross-sectional design.

SUBJECTS

Forth-five preterm infants, 34-36weeks of post-conceptional age, were distributed into groups: extreme preterm (EPT; 23-28weeks of gestational age; n=10), moderate preterm (MPT; 29-32weeks of gestational age; n=10), late preterm (LPT; 34-36weeks of gestational age; n=25).

OUTCOME MEASURES

All of the neonates were evaluated using the Neurobehavioral Assessment of Preterm Infant (NAPI) prior to 37weeks of post-conceptional age. The Neonatal Infant Stressor Scale (NISS) was applied for EPT and MPT infants during NICU hospitalization, and medical charts were analyzed.

RESULTS

The EPT group experienced significantly more acute stressful events during NICU hospitalization than the MPT group. The MPT group had lower scores in motor development and vigor than the EPT and LPT group, and they exhibited poorer quality crying than the LPT group. Motor development and vigor and alertness and orientation in preterm infants were predicted by prematurity level and acute stressful events.

CONCLUSION

The extreme preterm was exposed to higher stressful experiences than moderate and late preterm infants. However, the moderate preterm infants presented more vulnerable than the other counterparts in motor and vigor outcomes.

Infants with complex congenital heart diseases show poor short-term memory in the mobile paradigm at 3 months of age

The purpose of this study was to examine learning, short-term memory and general development including cognitive, motor, and language domains in infants with Complex Congenital Heart Defects (CCDH). Ten infants with CCHD (4 males, 6 females) and 14 infants with typical development (TD) were examined at 3 months of age. The mobile paradigm, where an infant's leg is tethered to an overhead mobile, was used to evaluate learning and short-term memory. The Bayley Scales of Infant Development 3rd edition (Bayley-III) was used to evaluate general development in cognitive, motor, and language domains. Infants with CCHD and infants with TD both showed learning with significant increase in kicking rate (p<0.001) across periods of the mobile paradigm, but only infants with TD demonstrated short-term memory (p=0.017) in the mobile paradigm. There were no differences on cognitive, motor, and language development between infants with CCHD and infants with TD on the Bayley-III. Early assessment is necessary to guide targeted treatment in infants with CCHD. One-time assessment may fail to detect potential cognitive impairments during early infancy in infants with CCHD. Supportive intervention programs for infants with CCHD that focuses on enhancing short-term memory are recommended.

Characterization and intervention for upper extremity exploration & reaching behaviors in infancy

This article aims to: 1) highlight general exploration, reaching, and object exploration behaviors as key activities of daily living in infancy, 2) describe how knowledge of early warning signs for these behaviors may improve early assessment, and 3) discuss interventions that may advance performance of these behaviors. Early intervention should focus on improving performance of these behaviors because: a) these early, interrelated upper extremity behaviors serve an integral role in global learning and development in infancy, b) among at-risk populations, differences have been observed in the quantity and quality of performance of these behaviors and, in many cases, these differences are associated with related perceptual-motor and cognitive delays. This article highlights how early assessment and intervention can target these key early behaviors in populations at risk for upper extremity disabilities, such as those born preterm, with Down syndrome, brachial plexus palsy, or arthrogryposis multiplex congentia.

Dynamic Assessment With the Bayley-III Among Young Children With Developmental Disabilities

This article describes the results of a pilot study into the newly developed dynamic version of the Bayley-III Cognition scale. We explored the responses of children to the dynamic version (n = 57) and the companion task behavior questionnaire (n = 93) using administrations among children with developmental disabilities. Furthermore, we studied the added clinical value compared to the standard Bayley-III using expert interviews with 6 educational psychologists. Results showed that there is clear variability in the responses of children to the help-steps that belong to the dynamic procedure and in the score difference between the pretest and posttest. The educational psychologists indicated that the dynamic procedure clearly has added value for specific groups of children, such as children in the preliminary stage of school placement and children from socially disadvantaged families. The task behavior questionnaire was evaluated positively by most educational psychologists. We conclude that the dynamic procedure provides added value for the developmental assessment of children with developmental disabilities. We finish with suggestions for future research into the dynamic Bayley-III.

Real-World Performance: Physical Activity, Play, and Object-Related Behaviors of Toddlers With and Without Disabilities

PURPOSE

To describe and compare the occurrence and co-occurrence of physical activity (PA), play, and object-related behaviors in toddlers with and without disabilities.

METHODS

Participants included 23 toddlers (21 with typical development (TD) and 2 with disabilities). Direct observation was used to describe the type and level of PA, play interactions, and object-related behaviors through video recordings.

RESULTS

Toddlers demonstrated high variability, occurrence, and co-occurrence of all behaviors. Toddlers with disabilities displayed less variability, occurrence, and co-occurrence of several behaviors.

CONCLUSION

Toddlers with TD engage simultaneously in PA, play, and object-related behaviors for about 3 hours in a typical day. This same level of co-occurrence of behaviors may not be observed for children with disabilities. Intervention providers are encouraged to consider the behaviors of toddlers with TD, beyond the findings of this pilot study, as the reference standard when implementing technology and intervention strategies for children with disabilities.

Reliability and validity of play-based assessments of motor and cognitive skills for infants and young children: a systematic review

BACKGROUND

Play is vital for development. Infants and children learn through play. Traditional standardized developmental tests measure whether a child performs individual skills within controlled environments. Play-based assessments can measure skill performance during natural, child-driven play.

PURPOSE

The purpose of this study was to systematically review reliability, validity, and responsiveness of all play-based assessments that quantify motor and cognitive skills in children from birth to 36 months of age.

DATA SOURCES

Studies were identified from a literature search using PubMed, ERIC, CINAHL, and PsycINFO databases and the reference lists of included papers.

STUDY SELECTION

Included studies investigated reliability, validity, or responsiveness of play-based assessments that measured motor and cognitive skills for children to 36 months of age.

DATA EXTRACTION

Two reviewers independently screened 40 studies for eligibility and inclusion. The reviewers independently extracted reliability, validity, and responsiveness data. They examined measurement properties and methodological quality of the included studies.

DATA SYNTHESIS

Four current play-based assessment tools were identified in 8 included studies. Each play-based assessment tool measured motor and cognitive skills in a different way during play. Interrater reliability correlations ranged from .86 to .98 for motor development and from .23 to .90 for cognitive development. Test-retest reliability correlations ranged from .88 to .95 for motor development and from .45 to .91 for cognitive development. Structural validity correlations ranged from .62 to .90 for motor development and from .42 to .93 for cognitive development. One study assessed responsiveness to change in motor development.

LIMITATIONS

Most studies had small and poorly described samples. Lack of transparency in data management and statistical analysis was common.

CONCLUSIONS

Play-based assessments have potential to be reliable and valid tools to assess cognitive and motor skills, but higher-quality research is needed. Psychometric properties should be considered for each play-based assessment before it is used in clinical and research practice.

Socioeconomic status and the growth of intelligence from infancy through adolescence

Low socioeconomic status (SES) children perform on average worse on intelligence tests than children from higher SES backgrounds, but the developmental relationship between intelligence and SES has not been adequately investigated. Here, we use latent growth curve (LGC) models to assess associations between SES and individual differences in the intelligence starting point (intercept) and in the rate and direction of change in scores (slope and quadratic term) from infancy through adolescence in 14,853 children from the Twins Early Development Study (TEDS), assessed 9 times on IQ between the ages of 2 and 16 years. SES was significantly associated with intelligence growth factors: higher SES was related both to a higher starting point in infancy and to greater gains in intelligence over time. Specifically, children from low SES families scored on average 6 IQ points lower at age 2 than children from high SES backgrounds; by age 16, this difference had almost tripled. Although these key results did not vary across girls and boys, we observed gender differences in the development of intelligence in early childhood. Overall, SES was shown to be associated with individual differences in intercepts as well as slopes of intelligence. However, this finding does not warrant causal interpretations of the relationship between SES and the development of intelligence.

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IQ growth trajectories were modeled in British children from age 2 to 16 years.

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Children's socioeconomic background (SES) was associated with IQ growth.

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High and low SES children differed by 6 IQ points at age 2.

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By age 16, this IQ difference between high and low SES children had tripled.

Infants born preterm demonstrate impaired object exploration behaviors throughout infancy and toddlerhood

BACKGROUND

Object exploration behaviors form the foundation for future global development, but little is known about how these behaviors are exhibited by infants born preterm.

OBJECTIVE

The study objective was to longitudinally compare a comprehensive set of object exploration behaviors in infants born preterm and infants born full-term from infancy into toddlerhood.

DESIGN

Twenty-two infants born full-term and 28 infants born preterm were monitored as they interacted with objects throughout their first 2 years.

METHODS

Infants were provided up to 30 seconds to interact with each of 7 objects across 9 visits. Experimenters coded videos of infants' behaviors. Growth modeling and t tests were used to compare how much infants exhibited behaviors and how well they matched their behaviors to the properties of objects.

RESULTS

Infants born preterm explored objects less in the first 6 months, exhibited less visual-haptic multimodal exploration, displayed reduced variability of exploratory behavior in a manner that reflected severity of risk, and were less able to match their behaviors to the properties of objects in a manner that reflected severity of risk. Infants born preterm with significant brain injury also had impaired bimanual abilities.

LIMITATIONS

There was a limited sample of infants born preterm with significant brain injury.

CONCLUSIONS

Infants born preterm have impaired abilities to interact with objects even in the first months of life. This impairment likely limits the knowledge they acquire about objects and about how they can act on them; this limited knowledge may, in turn, impair their early learning abilities. These results highlight the need for assessment and intervention tools specific for object exploration in young infants.

Not just playing around: infants' behaviors with objects reflect ability, constraints, and object properties

This study describes infants' behaviors with objects in relation to age, body position, and object properties. Object behaviors were assessed longitudinally in 22 healthy infants supine, prone, and sitting from birth through 2 years. Results reveal: (1) infants learn to become intense and sophisticated explorers within the first 6 months of life; (2) young infants dynamically and rapidly shift among a variety of behavioral combinations to gather information; (3) behaviors on objects develop along different trajectories so that behavioral profiles vary across time; (4) object behaviors are generally similar in supine and sitting but diminished in prone; and (5) infants begin matching certain behaviors to object properties as newborns. These data demonstrate how infants learn to match their emerging behaviors with changing positional constraints and object affordances.

Infant exploratory learning: influence on leg joint coordination

A critical issue in the study of infant development is to identify the processes by which task-specific action emerges from spontaneous movement. Emergent leg action has been studied by providing contingent reinforcement to specific leg movements using an overhead infant-activated mobile, however, there is limited information on the strategies used by infants to support the emergence of task-specific leg action from spontaneous movement. The purpose of this study is to (1) determine the ability of 3 month old infants to learn, through discovery, the contingency between leg action and mobile activation using a virtual threshold, and (2) identify strategies, defined by variance of the end-effectors (feet) and hip-knee joint coordination, used by infants that learned the contingency. Fourteen 3 month old infants participated in 2 sessions of mobile reinforcement on consecutive days. As a group, infants increased the percentage of mobile activation to meet performance criteria on Day 2, but did not meet memory or learning criteria across days. However, five infants learned the contingency based on individual learning criteria. When interacting with the mobile on Day 2 as compared to spontaneous kicking on Day 1, infants who learned the contingency, but not infants who did not learn the contingency, increased variance of the end-effectors (feet) in the vertical, task-specific direction and demonstrated less in-phase hip-knee joint coordination. An important discovery is that infants can discover this very specific contingency, suggesting that this movement behavior (action) can be shaped in future work. This may have implications for the rehabilitation of infants with atypical leg action.

Instability of delay classification and determination of early intervention eligibility in the first two years of life

The purpose of this study was to determine the effectiveness of the Bayley Scales of Infant Development, Third Edition (Bayley-III) to track development and classify delays in low- and high-risk infants across the first two years of life. We assessed cognitive, language, and motor development in 24 low-risk full-term and 30 high-risk preterm infants via seven assessments performed between 3 and 24 months corrected age. The Bayley-III resulted in highly unstable delay classifications, low sensitivities, and poor positive predictive values across time. The results highlight that early intervention professionals, researchers, and policy makers should: (1) emphasize clinical opinion and prevalence of risk factors rather than standardized assessment findings when classifying delays and determining eligibility for services, and (2) develop more effective developmental assessments for infants and young children.

The effect of a short bout of practice on reaching behavior in late preterm infants at the onset of reaching: a randomized controlled trial

The purpose of this study was to examine the effects of a short bout of practice on reaching behavior in late preterm infants at the onset of goal-directed reaching. The study was designed as a blind, three-arm parallel-group, randomized controlled, clinical trial. Thirty-six late preterm infants were recruited from a maternity hospital and allocated according to computer generated randomization into groups that received reaching practice based on either a blocked schedule, a serial schedule, or no practice. Practice consisted of a 4 min session of induced reaching using a toy in three activities guided by a physical therapist. The activities were elicited in separate blocks for the blocked practice group and in a pre-established order for the serial practice group. The control group stayed in the physical therapist's lap but was not stimulated to reach. The infants were assessed 3.3±1.4 days after the onset of goal-directed reaching in three tests: pre-test (immediately before practice), post-test (immediately after practice), and retention test (24 h after post-test). During assessments, the infants were seated in a baby chair and a toy was presented at his/her midline within reaching distance for 2 min. Changes in the number of reaches, proportions of uni/bimanual reaches and kinematic parameters of reaching were main outcome measures. From pre- to post-test, the amount of reaches and bimanual reaches increased in the serial practice group, but the increase was not maintained in the retention test. Kinematic parameters were not affected by practice. Changes in the reaching behavior of late preterm infants can be triggered after the first few minutes of toy-oriented experience based on a serial practice schedule. These changes are not consolidated one day later.