Infant posture and caregiver‐provided cognitive opportunities in typically developing infants and infants with motor delay

A matter of time: Developmental cascades for developmental science

The pace and breadth of infant development is remarkable-by their third birthday, infants acquire an impressive range of skills across multiple domains. Studying the complexities of cross-domain development, however, poses a challenge for a field of researchers with traditionally siloed expertise. The developmental cascades framework-the conceptual view that disparate domains are interconnected and reciprocally influential-offers researchers a flexible approach to identify and describe infant development. Over the past quarter century, cascades have surged in popularity among infancy researchers. In this review, we provide a history of developmental cascades research and highlight its contributions to the science of infant behavior and development. We discuss contemporary themes and challenges cascades researchers face (e.g., how to clear the high bar needed to establish causality among links in a cascading chain of events) and make recommendations for future research. Specifically, we propose that adopting a cascades approach encourages researchers to: (1) consider the 'whole child' by charting connections across different domains; (2) examine multiple timescales by linking moment-to-moment interactions to broader changes across development; (3) embrace complexity and foster interdisciplinary collaboration; and (4) gather evidence for causal pathways by combining the rigor of lab experiments with the richness of natural observations. Finally, we consider future directions for the next quarter century of cascades research-for developmental science, applied psychology, and clinical intervention.

Sitting and caregiver speech input in typically developing infants and infants with cerebral palsy

The development of independent sitting is associated with language development, but the learning experiences underlying this relationship are not well understood. Additionally, it is unknown how these processes play out in infants with motor impairments and delays in sitting development. We examined the real-time associations between sitting and caregiver speech input in 28 5-7-month-old infants with typical development and 22 7-16-month-old infants with cerebral palsy who were at a similar stage of early sitting development. We hypothesized that object labels would be more likely to co-occur with moments of optimal attention to the labeled object while sitting than while in other positions. Infants were video recorded in five minutes of free play with a caregiver. Coders transcribed caregivers' speech, identified instances of object labeling, and coded infants' and caregivers' attentional states during object labeling episodes. We found that caregivers labeled more objects while infants were sitting than while they were in other positions. However, object labels were not more likely to co-occur with infant attention, infant multimodal attention, or coordinated visual attention to the labeled object during sitting. Infants with cerebral palsy were exposed to fewer labels and were less likely to be attending to objects as they were labeled than infants with typical development. Our findings shed light on a possible pathway connecting sitting and language in typical and atypical development.

Context Shapes (Proto)Conversations in the First Year of Life

Speech development occurs in highly variable environments; however, little is known about the effect of situational context on emerging infant vocalizations. At 4 time points (4, 6, 9, and 12 months), we longitudinally measured vocalizations of 104 White infant-caregiver dyads (41 girls) during three play contexts: book-sharing, toy play, and rattle-shaking. The frequency of infant vocalizations differed between contexts only at 12 months of age. Meanwhile, caregivers systematically spoke more frequently during book-sharing than in other contexts from 4 months of age onwards. Book-sharing elicited more conversational turns at the dyadic level than in other contexts from 9 months of age. Our results show emergence of vocal differentiation of play context by infants and the role of book-sharing in facilitating early vocal turn-taking.

The Relationship Between Motor Development and ADHD: A Critical Review and Future Directions

Despite the prevalence of motor difficulties in individuals with attention-deficit/hyperactivity disorder (ADHD) throughout development, it is neglected as a factor underlying the etiology or functional impairment. This paper reviews the behavioral and neurological evidence linking motor difficulties to ADHD, arguing that existing theories explaining this relationship are oversimplified. Instead, embodied theories of development offer a more comprehensive evaluation of the mechanistic relationship among the motor system, cognitive development, and subsequent functional impairment in ADHD throughout early development. The integration of these perspectives will ultimately inform our understanding of the etiology of ADHD and inspire novel approaches for identification and intervention.

Postnatal dependency as the foundation of social learning in humans

Humans have developed a sophisticated system of cultural transmission that allows for complex, non-genetically specified behaviours to be passed on from one generation to the next. This system relies on understanding others as social and communicative partners. Some theoretical accounts argue for the existence of domain-specific cognitive adaptations that prioritize social information, while others suggest that social learning is itself a product of cumulative cultural evolution based on domain-general learning mechanisms. The current paper explores the contribution of humans' unique ontogenetic environment to the emergence of social learning in infancy. It suggests that the prolonged period of post-natal dependency experienced by human infants contributes to the development of social learning. Because of motor limitations, infants learn to interact with and act through caregivers, establishing social learning abilities and skills that continue to develop as children become less dependent. According to this perspective, at least some key aspects of social development can be attributed to a developmental trajectory guided by infants' early motor development that radically alters how they experience the world.

Sit and face the world: ontogenetic adaptation in infant vocal production and visual attention during the transition to independent sitting

BACKGROUND

Motor milestones are not only indicators of developmental progress, but they also open up new opportunities for infants to interact with the environment and social partners, as the development of motor, social, and language skills is tightly interconnected in infancy. This study will investigate how the transition to independent sitting relates to key areas of socio-communicative development in infancy: vocal production and visual attention.

METHODS

This study addresses the relationship between sitting acquisition and social cognition skills in infancy. It will allow for comparing if infant motor development, vocalizations, and visual attention undergo developmental changes in parallel or whether they have intertwined trajectories. We will conduct a longitudinal study using a milestone-based approach to account for individual differences in relation to the timing of motor milestone acquisition. We will invite parent-infant dyads to the lab when infants are at different stages of independent sitting acquisition: non-sitting, attempting-sitting and expert-sitting. Infants' attention toward faces and toys will be measured with a wearable eye-tracker during free-flowing dyadic interactions with their caregivers. During the same interactions, infant vocalizations will also be recorded and analyzed. Additionally, screen-based eye-tracking will be used to precisely assess changes in infants' attention to the mouth area of the speaker.

DISCUSSION

Altogether, this study will provide a unique dataset that tracks the cross-dependence of motor, visual and vocal developmental trajectories. It will have the potential to inform future studies of neurodevelopmental disorders such as autism that are characterized by socio-communicative challenges.

Role differentiated bimanual manipulation during a lab-based free play task

Infants spend a significant portion of their day engaging in play and accumulate immense amounts of object interactions. As infants develop, they perform increasingly complex bimanual actions, such as role differentiated bimanual manipulation (RDBM), where each hand serves a distinct role. RDBM has been well documented in structured lab settings, but these studies restrict the types of toys and postures in which infants can engage. Therefore, previous studies are limited in that they do not simulate everyday infant object interactions. Infants (39 13- and 39 24-month-olds) engaged in a 20-minute lab-based free play task designed to mimic everyday object interactions in order to assess the prevalence of RDBM and to understand the influence of posture, toy size, and toy weight on RDBM. Although both age groups frequently engaged in object interaction, RDBM did not occur as often in the lab-based free play task as found previously in structured settings. Whereas infants engaged in RDBM with toys of various sizes and weights, they favored lightweight toys and preferred to sit while engaging in RDBM. The 13-month-old infants preferred small toys while the 24-month-olds more often incorporated medium and large toys in their interactions. Examining RDBM using a lab-based free play task furthers our understanding of how complex bimanual behaviors emerge in a naturalistic setting where infants can adopt a wide range of postures and interact with a variety of toys.

Segmental trunk control and developmental parameters in children with cerebral palsy aged 24 to 42 months: A cross-sectional study

This study aimed (1) to investigate the relationship between segmental trunk control and motor, cognitive, and language development parameters in children with cerebral palsy (CP) and (2) to compare segmental trunk control levels and motor, language, and cognitive development in children with CP and typically developing (TD) peers. A cross-sectional observational study was conducted with 63 children aged between 24 and 42 months, including those with typical and atypical development. The atypical development group included 30 children with CP ranged from Gross Motor Function Classification System levels I to V (70.0% males, median age: 29 months, interquartile range: 25-36 months), and 33 children in the TD group (69.7% males, median age: 29 months, interquartile range: 26-36 months) included age-matched. Motor, language, and cognitive development domains were evaluated using the Bayley Scales of Infant and Toddler Development, Third Edition, and the level of trunk control was evaluated using the Segmental Assessment of Trunk Control. In children with CP, segmental trunk control was found to be strongly correlated with motor, cognitive, and language development (all P < .001, Spearman r ranged from 0.767-0.927). Furthermore, children with CP had lower segmental trunk control levels and cognitive, language, and motor development results than their TD peers (all P < .001). The strong relationship between segmental trunk control levels and developmental parameters can guide clinicians and therapists in planning and implementing intervention programs designed for children with CP who have difficulties in trunk control.

A pilot randomised controlled trial of ride-on cars and postural combinations of standing and sitting for mobility and social function in toddlers with motor delays

PURPOSE

Locomotor experiences in upright postures are essential for developing toddlers' mobility and social functions. This pilot randomised controlled trial aimed to examine the effectiveness of using a modified ride-on car (ROC) with postural combinations of standing and sitting on mobility and social function in toddlers with motor delays.

MATERIALS AND METHODS

Nineteen participants aged 1-3 years with mild, moderate or severe motor delays were randomly assigned to four ROC groups. The ROC groups had different combinations of standing and sitting, namely standing for 70 min (ROC-Stand70, five participants), standing for 45 min (ROC-Stand45, four participants), standing for 25 min (ROC-Stand25, five participants) and sitting for 70 min (ROC-Sit70, five participants). All participants participated in 2-h sessions twice a week for 12 weeks. The Pediatric Evaluation of Disability Inventory, Goal Attainment Scaling and Bayley-III tests were administered before and after the intervention, and after 12 weeks of follow-up. A mixed-model analysis of variance was used to compare inter- and intra-group differences. This trial was registered at ClinicalTrials.gov (NCT03707405).

RESULTS

All groups showed significantly improved mobility, social function and goal achievement at the post-test (p < .001). However, no significant changes were observed in Bayley scores.

CONCLUSIONS

Combining physical and social environmental modifications with active exploration is crucial for early power mobility training in toddlers with motor delays. To enhance the robustness and generalisability of our findings, future studies should include larger sample sizes, consider variations in motor delays, and measure energy expenditure during the intervention.Implications for rehabilitationProviding active exploratory experience using ride-on cars (ROCs) with various postural combinations can improve a child's mobility.The ROC training with various postural combinations can improve social function, and the degree of improvement may depend on the severity of motor delays.Setting goals with caregivers and incorporating their roles in the training process can empower them to interact with children more frequently and actively.

Identifying Infant Body Position from Inertial Sensors with Machine Learning: Which Parameters Matter?

The efficient classification of body position is crucial for monitoring infants' motor development. It may fast-track the early detection of developmental issues related not only to the acquisition of motor milestones but also to postural stability and movement patterns. In turn, this may facilitate and enhance opportunities for early intervention that are crucial for promoting healthy growth and development. The manual classification of human body position based on video recordings is labour-intensive, leading to the adoption of Inertial Motion Unit (IMU) sensors. IMUs measure acceleration, angular velocity, and magnetic field intensity, enabling the automated classification of body position. Many research teams are currently employing supervised machine learning classifiers that utilise hand-crafted features for data segment classification. In this study, we used a longitudinal dataset of IMU recordings made in the lab in three different play activities of infants aged 4-12 months. The classification was conducted based on manually annotated video recordings. We found superior performance of the CatBoost Classifier over the Random Forest Classifier in the task of classifying five positions based on IMU sensor data from infants, yielding excellent classification accuracy of the Supine (97.7%), Sitting (93.5%), and Prone (89.9%) positions. Moreover, using data ablation experiments and analysing the SHAP (SHapley Additive exPlanations) values, the study assessed the importance of various groups of features from both the time and frequency domains. The results highlight that both accelerometer and magnetometer data, especially their statistical characteristics, are critical contributors to improving the accuracy of body position classification.

Evaluation of the Movement and Play Opportunities and Constraints Associated With Containers for Infants

PURPOSE

Containers (eg, strollers, bouncers) are an important part of infants' environment but may negatively impact infant development and health. This study evaluated movement and play opportunities, constraints, and manufacturers' developmental claims for infant containers.

METHODS

Containers were identified through Amazon.com. A content analysis of identified products was conducted to identify movement and visual-manual play opportunities, constraints, and developmental claims.

RESULTS

Content was analyzed for 460 containers. Containers varied in their movement and play opportunities; however, most did not incorporate toys and restricted trunk movement, self-directed locomotion, and independent head and trunk control. Containers, especially those with built-in toys, often had claims related to gross motor, sensory, and fine motor development.

CONCLUSION

These findings demonstrate the variability of movement and play opportunities observed across and within categories of infant containers. General recommendations about container use may be less effective than more specific education to parents about selecting and implementing containers.

Reaching While Learning to Sit: Capturing the Kinematics of Co-Developing Skills at Home

This study examined the co-development of infant reaching and postural control across the transition to arms-free sitting at home. We observed infants with typical likelihood (TL; n = 24) and elevated likelihood (EL; n = 20) for autism at four biweekly sessions spanning the transition to arms-free sitting (infant age = 4.5-8 months at first session). At each session, infants sat on a pressure-sensitive mat with external support or independently, wore magneto-inertial sensors on both wrists, and reached for toys presented at midline. Analyses focused on characterizing and comparing control of sitting during reaching actions and standard kinematic metrics of reaching during Supported versus Independent Sitting. Although EL infants achieved arms-free sitting later than TL peers, there were no group differences on any measures. Across sessions, infants' control of the sitting posture during concurrent reaching movements improved in both contexts, though they were less stable as they reached when sitting independently compared to when sitting with support. A similar effect was apparent in the kinematics of reaches, with overall improvement over time, but evidence of poorer control in Independent relative to Supported Sitting. Taken together, these findings underscore the mutually influential and dynamic relations between emerging skills and well-established behaviors.

The implementation of EMI-Heart, a family-tailored early motor intervention in infants with complex congenital heart disease, in practice: a feasibility RCT

BACKGROUND

Children with congenital heart disease (CHD) who undergo open-heart surgery are at risk of developmental impairment, including motor delay, which contributes to parental concerns. Additionally, parents experience prolonged stress associated with their child's disease. There is a lack of early motor interventions in infants with CHD accounting for parental burdens. We developed a family-tailored early motor intervention (EMI-Heart), aiming to promote motor development in infants with CHD and family well-being. The primary aim was to evaluate the feasibility of the study design and the intervention. The secondary aim was to evaluate differences between the intervention and the control group in motor outcomes and family well-being at baseline (3-5 months), post-treatment (6-8 months), and at follow-up (12 months).

METHOD

In this single-centre feasibility randomized control trial (RCT), infants with CHD after open-heart surgery without genetic or major neurological comorbidities were randomly allocated to EMI-Heart or the control group (standard of care). EMI-Heart's key elements promote postural functional activities and encourage parental sensitivity to infants' motor and behaviour cues. Infants assigned to EMI-Heart received nine sessions of early motor intervention at home, in the hospital, and online for a duration of 3 months by a paediatric physiotherapist. We performed descriptive statistics for feasibility and secondary outcomes.

RESULTS

The recruitment rate was 59% (10/17), all participating families completed the study (10/10), and the intervention duration was 3.9 months (± 0.54), including nine intervention sessions per family. Median acceptability to parents was 3.9 (1 = not agree-4 = totally agree, Likert scale). The paediatric physiotherapist considered the intervention as feasible. The comparison of motor outcomes did not show differences between groups. However, we detected improved reliable change scores in family well-being outcomes for families of the intervention group compared to the controls.

CONCLUSIONS

Our research indicates that EMI-Heart is a feasible intervention for infants with CHD after open-heart surgery. The intervention was highly acceptable both to parents and to the paediatric physiotherapist. Online treatment sessions offer a valuable alternative to home and hospital visits. This feasibility RCT provides a foundation for a future full trial.

TRIAL REGISTRATION

ClinicalTrials.gov, NCTT04666857. Registered 23.11.2020.

Early object skill supports growth in role-differentiated bimanual manipulation in infants

The ability to coordinate the hands together to act on objects where each hand does something different is known as role-differentiated bimanual manipulation (RDBM). This study investigated two motor skills that may support the development of RDBM: infants' early object skill and their early sitting skill. To evaluate these potential predictors of RDBM growth, 90 infants were examined in a lab-based longitudinal design over a 9-month period. Latent growth modeling was used to estimate RDBM growth trajectories over 9 to 14 months from infants' object and sitting skills at 6 months, controlling for infant's sex, mother's education, and family income. Higher object skill, controlling for sitting skill, was related to a higher increase in RDBM over time. Sitting did not predict infants' change in RDBM over time, controlling for object skill. The ability to manage multiple objects may support collaborative hand use by providing infants with opportunities to practice actions that will be needed later for RDBM. By comparison, sitting may free the hands in an unspecified manner for manipulation.

Motor-language links in children with Down syndrome: a scoping review to revisit the literature with a developmental cascades lens

Background

Children with Down syndrome (DS) typically have motor and language needs. Improving function is a shared goal for the rehabilitation therapy team, however physical therapy, occupational therapy, and speech-language pathology professionals treat patients differently. This difference in care may mask developmental cascades whereby changes in one domain (e.g., motor) can have seemingly unexpected effects on another domain (e.g., language).

Objective

This scoping review identified papers where motor and language data have been reported together in children with DS and reinterpreted findings from a developmental cascades lens.

Design

Online databases were used to identify 413 papers published before October 2021 from which 33 papers were retained that reported both motor (gross and/or fine) and language (expressive and/or receptive) data in individuals with DS with a chronological age of 0-18 years.

Results

The majority of papers (79%) that reported motor and language data in children with DS did not examine their link, while 12% analyzed motor-language links, but using a cross-sectional or retrospective design. Only three papers (9%) utilized a longitudinal design to examine predictive links.

Conclusion

Motor functioning and language functioning have often been reported together, but not analyzed together, in studies of children with DS. The few studies that did analyze motor-language links largely replicated findings from other developmental populations where motor gains were positively linked to language gains. Analyzing links between domains when such data is available is needed to fully characterize developmental cascades in DS and may have broad clinical implications.

Sitting Capacity and Performance in Infants with Typical Development and Infants with Motor Delay

AIMS

Infants with neuromotor disorders demonstrate delays in sitting skills (decreased capacity) and are less likely to maintain independent sitting during play than their peers with typical development (decreased performance). This study aimed to quantify developmental trajectories of sitting capacity and sitting performance in infants with typical development and infants with significant motor delay and to assess whether the relationship between capacity and performance differs between the groups.

METHODS

Typically developing infants (n = 35) and infants with significant motor delay (n = 31) were assessed longitudinally over a year following early sitting readiness. The Gross Motor Function Measure (GMFM) Sitting Dimension was used to assess sitting capacity, and a 5-min free play observation was used to assess sitting performance.

RESULTS

Both capacity and performance increased at a faster rate initially, with more deceleration across time, in infants with typical development compared to infants with motor delay. At lower GMFM scores, changes in GMFM sitting were associated with larger changes in independent sitting for infants with typical development, and the association between GMFM sitting and independent sitting varied more across GMFM scores for typically developing infants.

CONCLUSIONS

Intervention and assessment for infants with motor delay should target both sitting capacity and sitting performance.

START-Play Physical Therapy Intervention Indirectly Impacts Cognition Through Changes in Early Motor-Based Problem-Solving Skills

PURPOSE

This study tested whether the Sitting Together and Reaching to Play (START-Play) physical therapy intervention indirectly impacts cognition through changes in perceptual-motor skills in infants with motor delays.

METHODS

Participants were 50 infants with motor delays randomly assigned to START-Play plus Usual Care Early Intervention (UC-EI) or UC-EI only. Infants' perceptual-motor and cognitive skills were assessed at baseline and 1.5, 3, 6, and 12 months post-baseline.

RESULTS

Short-term changes in sitting, fine motor skills, and motor-based problem-solving, but not reaching, predicted long-term changes in cognition. START-Play indirectly impacted cognition through motor-based problem-solving but not sitting, reaching, or fine motor skills.

CONCLUSIONS

This study provided preliminary evidence that early physical therapy interventions that blend activities across developmental domains and are supported by an enriched social context can place infants on more optimal developmental trajectories.

Opportunities for learning and social interaction in infant sitting: Effects of sitting support, sitting skill, and gross motor delay

The development of independent sitting changes everyday opportunities for learning and has cascading effects on cognitive and language development. Prior to independent sitting, infants experience the sitting position with physical support from caregivers. Why does supported sitting not provide the same input for learning that is experienced in independent sitting? This question is especially relevant for infants with gross motor delay, who require support in sitting for many months after typically developing infants sit independently. We observed infants with typical development (n = 34, ages 4-7 months) and infants with gross motor delay (n = 128, ages 7-16 months) in early stages of sitting development, and their caregivers, in a dyadic play observation. We predicted that infants who required caregiver support for sitting would spend more time facing away from the caregiver and less time contacting objects than infants who could sit independently. We also predicted that caregivers of supported sitters would spend less time contacting objects because their hands would be full supporting their infants. Our first two hypotheses were confirmed; however, caregivers spent surprisingly little time using both hands to provide support, and caregivers of supported sitters spent more time contacting objects than caregivers of independent sitters. Similar patterns were seen in the group of typically developing infants and the infants with motor delay. Our findings suggest that independent sitting and supported sitting provide qualitatively distinct experiences with different implications for social interaction and learning opportunities. HIGHLIGHTS: During seated free play, supported sitters spent more time facing away from their caregivers and less time handling objects than independent sitters. Caregivers who spent more time supporting infants with both hands spent less time handling objects; however, caregivers mostly supported infants with one or no hands. A continuous measure of sitting skill did not uniquely contribute to these behaviors beyond the effect of binary sitting support (supported vs. independent sitter). The pattern of results was similar for typically developing infants and infants with gross motor delay, despite differences in age.

Dynamics of the dyad: How mothers and infants co-construct interaction spaces during object play

Studies of dyadic interaction often examine infants' social exchanges with their caregivers in settings that constrain their physical properties (e.g., infant posture, fixed seating location for infants and adults). Methodological decisions about the physical arrangements of interaction, however, may limit our ability to understand how posture and position shape them. Here we focused on these embodied properties of dyadic interaction in the context of object play. We followed 30 mother-infant dyads across the first year of life (at 3, 6, 9, and 12 months) and observed them during 5 min of play with a standard set of toys. Using an interval-based coding system, we measured developmental change in infant posture, how mothers and infants positioned themselves relative to one another, and how they populated interaction spaces with objects. Results showed that mother-infant dyads co-constructed interaction spaces and that the contributions of each partner changed across development. Dyads progressively adopted a broader spatial co-orientation during play (e.g., positioned at right angles) across the first year. Moreover, advances in infants' postural skills, particularly increases in the use of independent sitting in real time, uniquely predicted change in dyadic co-orientation and infants' actions with objects, independent of age. Taken together, we show that the embodied properties of dyadic object play help determine how interactions are physically organized and unfold, both in real time and across the first year of life.

A family-tailored early motor intervention (EMI-Heart) for infants with complex congenital heart disease: study protocol for a feasibility RCT

BACKGROUND

Children with congenital heart disease (CHD) undergoing open-heart surgery are at risk for developmental impairments with motor delay manifesting first and contributing to parental concerns. Only a few interventional studies aim to improve neuromotor development in infants with CHD with inconclusive results. We thus developed a family-tailored early motor intervention (EMI-Heart), which aims to promote motor development and family well-being in the first year of life after open-heart surgery. The primary aim described in this protocol is to evaluate feasibility of EMI-Heart. The secondary aim is to describe the difference between the intervention and control group in motor outcomes and family well-being at baseline, post-treatment, and follow-up.

METHODS

This prospective, parallel single-center feasibility randomized controlled trial (RCT) will compare EMI-Heart with standard of care in infants with complex CHD. Sixteen infants and their families, randomly allocated to EMI-Heart or the control group, will participate within the first 5 months of life. Infants assigned to EMI-Heart will receive early motor intervention for 3 months. The intervention's key is to promote infants' postural control to enhance motor development and partnering with parents to encourage family well-being. Feasibility outcomes will be (a) clinical recruitment rate and percentage of families completing EMI-Heart, (b) average duration and number of sessions, and (c) acceptability of EMI-Heart using a parental questionnaire post-treatment, and descriptive acceptability of EMI-Heart to the pediatric physiotherapist. Secondary outcomes of the intervention and control group will be infants' motor outcomes and questionnaires assessing family well-being at 3-5 months (baseline), at 6-8 months (post-treatment), and at 12 months of age (follow-up). We will evaluate feasibility using descriptive statistics. Non-parametric statistical analysis of secondary outcomes will assess differences between the groups at baseline, post-treatment, and follow-up.

DISCUSSION

This feasibility RCT will provide information about a newly developed family-tailored early motor intervention in infants with complex CHD. The RCT design will provide a foundation for a future large-scale interventional trial for infants with CHD after open-heart surgery.

TRIAL REGISTRATION

This study protocol (version 1.3, 01.02.2022) was approved by the Cantonal Ethics Commission Zurich (BASEC-Nr. 2019-01,787) and is registered by Clinicaltrials.gov (NCTT04666857).

Developing language in a developing body, revisited: The cascading effects of motor development on the acquisition of language

In the first years of life, infants rapidly acquire a series of new motor skills. They learn to sit independently, to walk with skill, and to engage in a wide variety of interactions with objects. Over these same years, infants also begin to develop language. These are not isolated events. In a complex developing system, even small changes in one domain can have far-reaching effects on development in other domains. This is the fundamental idea behind the rich framework known as the developmental cascades perspective. Here we employ this framework to show how early motor advances can exert downstream effects on the development of language. Focusing first on the emergence of independent sitting, then on the development of walking, and finally on changes in the ways in which infants act on and combine actions on objects, we describe how the nature and quality of infant actions change dramatically over the first few years and how this brings with it new possibilities for engaging the environment, more sophisticated ways of interacting with people, and significant alterations in communications directed by caregivers to the infant and coordinated with infant action in time and in meaning. The developmental cascades framework provides an approach for understanding how advances in motor skills influence communicative and language development, and more generally, for conceptualizing the constant, dynamic, and complex interplay between developing infants and their environments as it unfolds over time. This article is categorized under: Linguistics > Language Acquisition Psychology > Motor Skill and Performance Psychology > Development and Aging.

Effect of the START-Play Physical Therapy Intervention on Cognitive Skills Depends on Caregiver-Provided Learning Opportunities

AIMS

This study evaluated whether caregiver-provided learning opportunities moderated the effect of START-Play physical therapy intervention on the cognitive skills of young children with neuromotor delays, and whether START-Play impacted caregiver-provided learning opportunities over time.

METHODS

One hundred and twelve children with neuromotor delays (7-16 months) participated in a multisite randomized clinical trial evaluating the efficacy of START-Play. Children were assessed at baseline and 3 (post intervention), 6, and 12 months post baseline. Cognition was scored from the Bayley Scales of Infant & Toddler Development, Third Edition, cognitive scale. The proportion of time caregivers spent providing learning opportunities was coded from a 5-minute caregiver-child free play interaction.

RESULTS

Baseline caregiver-provided learning opportunities moderated the 3- and 12-month effects of START-Play on cognition. Cognitive gains due to START-Play were more pronounced for children whose caregivers provided more learning opportunities. START-Play did not impact caregiver-provided learning opportunities over time.

CONCLUSIONS

START-Play may have a lasting effect on children's cognition, but this effect is contingent on caregivers providing their child with ample opportunities to practice cognitive skills. Strategies for improving caregivers' uptake and transfer of START-Play principles to their daily routines should be evaluated.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02593825.

Early development in autism: How developmental cascades help us understand the emergence of developmental differences

Many theories of autism spectrum disorder (ASD) focus on a single system or factor as an explanatory mechanism for autism symptoms and behavior. However, there is growing recognition that ASD is a complex, multisystem neurodevelopmental condition with origins in prenatal life. Researchers therefore need a conceptual framework that allows examination of the interplay between multiple interacting domains and systems and the ways in which they extend their influence beyond the individual into the surrounding environment. The developmental cascades perspective suggests that even relatively small perturbations in early emerging behaviors in domains that are not traditionally linked may influence subsequent achievements across these areas. In this chapter, we illustrate how a developmental cascades framework can be used to inform the study of developmental differences. The developmental cascades perspective provides us with conceptual and methodological tools for considering how variation in children's real time behavior can provide new insights into sources of variation in their developmental trajectories and outcomes. It also suggests approaches for intervention that leverage targeted skills in novel ways, creating opportunities to support development in other domains and fine-tune caregiver behavior to create powerful moments for infant learning.