Real-time teaching and learning: Caregivers teaching infants to descend stairs.

Learning to descend stairs requires motor and cognitive capacities on the part of infants and opportunities for practice and assurance of safety offered by caregivers. The American Academy of Pediatrics prescribes the age strategy to teach toddlers to safely descend stairs but without much consideration for individual differences in infants' skills or caregivers' techniques. The purpose of this study was to observe the natural ways in which caregivers teach infants to descend stairs at home and the extent to which infants abide. Of particular interest was to examine the dynamic nature of caregivers' teaching and infants' learning over the session with attention to individual differences. Dyads (N = 59) were videorecorded on Zoom for 10 min interacting on stairs at home in the United States, Brazil, Canada, Italy, and Spain. Infants (n = 30 girls, 29 boys; 13-month-olds ± 1 week) were novice walkers (M = 2.04 months walking experience). Caregivers used a variety of teaching strategies and focused on "backing" and "scooting." Infants were more likely to heed caregivers' guidance when caregivers provided hands-on support and verbal encouragement suggesting infants were engaged and responsive to caregivers' overtures. Infants' walking experience predicted change in descent strategy over the session. Although infants did not show evidence of learning over the session, consistent caregiver instruction suggested caregivers were persistent, if not effective, teachers. Teaching and learning motor skills in a potentially risky task creates a unique opportunity for interaction, allowing infants and caregivers to learn from one another. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Focused attention as a new sitter: How do infants balance it all?

This study investigated the impact of postural control on infants' Focused Attention (FA). Study 1 examined whether and how sitting independently versus with support impacted 6- to 8-month-old infants' ability to focus attention during object exploration. FA measures did not depend on support condition. However, sitting experience was significantly negatively correlated with FA measures in the supported condition, suggesting that infants with more sitting experience performed fewer exploratory movements, possibly due to faster information processing ability compared to infants with less sitting experience. These unexpected findings prompted an exploration of more subtle looking behaviors during FA in Study 2-a case study of three infants who wore a head-mounted eye-tracker during an FA task. The ability to rapidly shift visual attention was key to gathering environmental information useful for problem solving-an interpretation that is supported by prior findings of the relationship between fast looks and faster information processing.

Three decades of infant motor development: Cohort effects in motor skill onsets.

Infant motor development is affected by the sociocultural context in which it takes place. Because societal and cultural practices are dynamic, this exploratory study examined whether the ages at which infants typically learned to crawl, cruise, and walk changed over the past 3 decades. We compiled archival data from 1,306 infants born between January 31, 1992, and December 10, 2021. Parents originally reported milestone onsets in interviews and by using diaries. For each motor milestone, a linear regression model predicted the onset age using birth date. Segmented regression analyses inspected changes in slopes over time. Covariates included rural/urban housing, gestation age, season of birth, and birth weight. Infants' average crawling, cruising, and walking onset ages changed over time. After controlling for the covariates, infants' crawling onset age steadily increased until 2012, after which crawling onset age decreased. Infants' cruising onset age increased from 1991 to 2001, after which cruising onset age remained stable. After controlling for the covariates, infants' walking onset increased until 2015, after which walking onset age decreased. Thus, when infants were born explained a small but significant amount of variability in infant motor skill onset. While the current study showed that motor development changed over the years, motor development is just a model system for development more generally: Cohort effects may be pervasive across developmental domains. Using motor development as a model system for studying change suggests that generational effects due to a changing society may be pervasive across developmental domains. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The impact of extreme summer temperatures in the United Kingdom on infant sleep: Implications for learning and development.

The U.S. Global Change Research Program reports that the frequency and intensity of extreme heat are increasing globally. Studies of the impact of climate change on child health often exclude sleep, despite its importance for healthy growth and development. To address this gap in the literature, we studied the impact of unusually high temperatures in the summer of 2022 on infants' sleep. Sleep was assessed objectively using Nanit camera monitors in infants' homes. Generally, sleep was not impacted when temperatures stayed below 88° but was negatively impacted when temperatures reached over 100°. Compared to non-heatwave nights, infants had less total sleep, less efficient sleep, took longer to fall asleep, had more fragmented sleep, and parents' visits were more frequent during the night. Following peaks in temperature, sleep metrics rebounded to better than average compared to non-peak nights, suggesting that infants compensated for disrupted sleep by sleeping more and with fewer interruptions once the temperature dropped below 85°. Increased instances of disrupted sleep in infancy have important implications for psychological health and development. Climate disruptions such as heat waves that create occasional or ongoing sleep disruptions can leave infants vulnerable and unprepared for learning.

Infant motor development predicts the dynamics of movement during sleep.

The characteristics of infant sleep change over the first year. Generally, infants wake and move less at night as they grow older. However, acquisition of new motor skills leads to temporary increases in night waking and movement at night. Indeed, sleep-dependent movement at night is important for sensorimotor development. Nevertheless, little is known about how movement during sleep changes as infants accrue locomotor experience. The current study investigated whether infant sleep and movement during sleep were predicted by infants' walking experience. Seventy-eight infants wore an actigraph to measure physical activity during sleep. Parents reported when their infants first walked across a room >10 feet without stopping or falling. Infants in the midst of walking skill acquisition had worse sleep than an age-group estimate. Infants with more walk experience had more temporally sporadic movement during sleep and a steeper hourly increase in physical activity over the course of the night. Ongoing motor skill consolidation changes the characteristics of movement during sleep and may alter sleep state-dependent memory consolidation. We propose a model whereby changes in gross motor activity during night sleep reflect movement-dependent consolidation.

The unique contributions of day and night sleep to infant motor problem solving.

The current study sought to tease apart the unique contributions of napping and nighttime sleep to infant learning, specifically in the context of motor problem solving. We challenged 54 walking infants to solve a novel locomotor problem at three time points-training, test, and follow-up the next morning. One group of infants napped during the delay between training and test. Another group did not sleep during the delay. A third group received the test immediately after training with no delay. Only the Nap group's strategy choices continued to improve through the follow-up session, suggesting that daytime sleep has an active role in strengthening otherwise fragile memory. Although group did not affect strategy maintenance, walk experience did, suggesting that task difficulty may shape the impact of sleep on learning. Thus, day sleep and night sleep make independent contributions to the consolidation of motor problem-solving strategies during infancy.

Nap timing makes a difference: Sleeping sooner rather than later after learning improves infants' locomotor problem solving.

Twenty-nine newly-walking infants who had recently given up crawling trained to navigate a shoulder-height, nylon tunnel to reach a caregiver waiting at the other end. Infants in the Nap First group napped within 30 min of initial training. Infants in the Delay First group napped four hours after training. All infants were retested six hours after training on the same locomotor problem. Learning was measured by the number of training prompts required to solve the task, exploration, and time to solve the problem. Nap First infants benefited the most from a nap; they required fewer training prompts, used fewer posture shifts from training to test, and solved the task faster compared to Delay First infants, suggesting that optimally timed sleep does not merely protect against interference, but actively contributes to memory consolidation. This study highlights the importance of nap timing as a design feature and was a first step towards limit-testing the boundaries of the relation between sleep and learning. Infants' fragile memories require regular consolidation with intermittent periods of sleep to prevent interference or forgetting.

A time series analysis of the relation between motor skill acquisition and sleep in infancy.

To systematically examine the relation between motor milestone onset and disruption of night sleep in infancy, three families kept microgenetic, prospective, daily checklist diaries of their infants' motor behavior and sleep (197-313 observation days; 19,000 diary entries). Process control and interrupted time series analyses examined whether deviations from the moving average for night wakings and evening sleep duration were temporally linked to motor skill onset and tested for meaningful differences in individual sleep patterns before and after skill onset. Model assumptions defined skill onset as first day of occurrence or as mastery and moving average windows as 3, 7, or 14 days. Changes in infants' sleep patterns were associated with changing expertise for motor milestones. The temporal relation varied depending on infant and sleep parameter. Intensive longitudinal data collection may increase our understanding of micro-events in infant development.

Making the process of strategy choice visible: Inhibition and motor demands impact preschoolers' real-time problem solving.

To examine the real-time process of strategy choice and execution and the role of inhibition in problem solving, 4- to 6-year-old children were asked to navigate a ball around a maze board under high- and low-precision motor demands. Employing a motor problem-solving task made normally hidden cognitive processes observable. Sequential analysis revealed two subtypes of inhibition (response and attentional) that are involved in problem solving and different developmental trajectories for each. Cognition-action trade-offs due to motor and inhibition demands adversely impacted children's strategy choices, but contributed to heightened variability of strategies. Children used fewer strategies with age, reflecting more efficient problem solving due to increasing inhibitory control. When solutions required precision, preschoolers were more likely to have difficulty inhibiting irrelevant and distracting strategies and maintaining appropriate strategies. By preschool age, executive functioning serves to make strategic motor control possible. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=TCLxK7dvheE.

Researcher Choices for Infant Sleep Assessment: Parent Report, Actigraphy, and a Novel Video System.

Incorporating infant sleep, either as a predictor or as an outcome variable, into interdisciplinary work has become increasingly popular. Sleep researchers face many methodological choices that have implications for the reliability and validity of the data. Here, the authors directly investigated the impact of design and measurement choices in a small, longitudinal sample of infants. Three sleep measurement techniques-parent-reported sleep diaries, actigraphy (Micromini Sleep Watch), and a commercial videosomnography (Nanit)-were included, using actigraphy as the baseline. Nine infants' sleep (4 girls) was measured longitudinally using all three measurement techniques. Nanit provided summary statistics, using a proprietary algorithm, for nightly sleep parameters. The actigraphy data were analyzed with both the Sadeh Infant and Sadeh algorithms. The extent to which measurements converged on sleep start and end time, number of wake episodes, sleep efficiency, and sleep duration was assessed. Measures were positively correlated. Difference scores revealed similar patterns of greater sleep estimation in parent reports and Nanit compared with actigraphy. Bland-Altman plots revealed that much of the data were within the limits of agreement, tentatively suggesting that Nanit and actigraphy may be used interchangeably. Graphs display significant variability within and between individual infants as well as across measurement techniques. Potential confounding variables that may explain the discrepancies between parent report, Sadeh Infant, Sadeh, and Nanit are discussed. The findings are also used to speak to the advantages and disadvantages of design and measurement choices. Future directions focus on the unique contributions of each measurement technique and how to capitalize on them.

Newly walking infants' night sleep impacts next day learning and problem solving.

Sleep is part of the process that prepares children and adults for next day cognitive activity. Insufficient or fragmented sleep has a detrimental impact on subsequent encoding (Rouleau et al., 2002) and cognitive functioning (Joo et al., 2012). However, fragmented sleep early in life is a developmental norm, limiting the extent to which conclusions derived from older populations can be generalized. To directly test the continuity of this relationship, newly-walking infants' (N=58) sleep was monitored overnight using actigraphy. The next morning they were taught a motor problem-solving task. The task required infants to navigate through a tunnel to reach a goal at the other end. We coded infants' exploratory behaviors and the extent of training required to solve the task. Using a cluster analysis that accounted for exploratory behaviors and number of training prompts, infants were sorted into three profiles: those who found the task Easy to solve, those who found it Difficult, and those who Never solved it. Wake episodes and sleep efficiency were entered as predictors of cluster membership in a multinomial logistic regression. Of the infants who ultimately solved the task, those with more wake episodes and lower sleep efficiency had more difficulty. Specifically, fragmentation appeared to negatively impact preparedness to learn. Contrary to our expectations, infants who Never solved the task had the least fragmented sleep, indicating that an optimal level of fragmentation is needed for efficient problem-solving. For infants, some level of sleep fragmentation is needed the night before learning in order to solve a task efficiently. These findings highlight the interaction between developmental domains, from sleep quality to motor experience, and their impact on infant learning in real time.

Embodied Cognition in Practice: Exploring Effects of a Motor-Based Problem-Solving Intervention.

BACKGROUND: Embodied cognition interests physical therapists because efforts to advance motor skills in young infants can affect learning. However, we do not know if simply advancing motor skill is enough to support advances in cognition. OBJECTIVE: The objective was to examine the effect of 2 interventions on the developing motor skill of sitting and problem solving and to describe the feasibility of using eye-tracking technology to explore visual and motor interaction. DESIGN: This was a longitudinal, randomized comparison of interventions. METHODS: Twenty infants with developmental delay and/or cerebral palsy, ranging in age from 8 to 34 months (mean [SD] = 15 [6.9] months), participated in an intervention emphasizing motor-based problem solving, and an intervention focused on advancing motor skill through assistance for attaining optimal movement patterns. Outcome measures were the Gross Motor Function Measure sitting subsection and the Early Problem Solving for Infants test. Active touch and looks were measured with eye-tracking technology. RESULTS: Participants in both groups made significant motor gains from baseline, with no difference between intervention groups on Gross Motor Function Measure change scores. Participants in the problem-solving group showed significant gains in Early Problem Solving for Infants scores over the participants in the optimal movement patterns group. Overall, participants increased active touch of toys and increased concurrent looking with active touching. LIMITATIONS: This exploratory study was small, with variation in participants' skills. The sampled behaviors for analysis were a small portion of the overall function of the participant. CONCLUSIONS: An intervention using motor-based problem solving could improve infants' problem-solving skill. The use of eye-tracking could help to understand embodied cognition as infants develop, but the challenges of embedding the method in natural settings require further work. Listen to the author interview at https://academic.oup.com/ptj/pages/podcasts.

Sit Still and Pay Attention! Trunk Movement and Attentional Resources in Infants with Typical and Delayed Development.

AIMS: (1) examine infant movement during an early posture (sitting) utilizing a novel video assessment technique; and (2) document the differences between infants with typical development (TD), premature infants with motor delay, and infants with cerebral palsy (CP) during focused and nonfocused attention (NFA). METHODS: Infants were tested when they began to sit independently. We utilized Eulerian Video Magnification (EVM) to accentuate small trunk and pelvic movements for visual coding from video taken during a natural play task with and without focused attention (FA). RESULTS: Trunk/pelvic movement varied as a function of both motor skill and attention. Infants with TD and CP made fewer trunk movements during periods of FA than NFA. Preterm infants exhibited more trunk/pelvic movement than the other groups and their movement did not differ based on attention type. CONCLUSIONS: The EVM technique allowed for replicable coding of real-time "hidden" motor adjustments from video. The capacity to minimize extraneous movements in infants, or "sitting still" may allow greater attention to the task at hand, similar to older children and adults. Premature infants' excessive trunk/pelvic movement that did not adapt to task requirements could, in the long term, impact tasks requiring attentional resources.

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.

The Trajectory of Concurrent Motor and Vocal Behaviors Over the Transition to Crawling in Infancy.

To document the trajectory of motor and vocal behaviors in real and developmental time, researchers observed infants at each of 4 biweekly naturalistic play sessions over the transition to crawling. An exhaustive and mutually exclusive coding scheme documented every vocalization and posture. Odds ratios of the likelihood of a given posture-vocalization dyad revealed that vocalization and crawling were significantly unlikely to co-occur at the session marking the onset of crawling. Infants' allocation of attention over the transition to crawling prompted behavioral trade-offs. During mastery of a novel skill, infants had difficulty allocating attention to multiple tasks, but with experience a decrease in attentional load for the new skill allowed performance of simultaneous behaviors in other domains to occur.

Naps improve new walkers' locomotor problem solving.

In this first study of the impact of sleep on infants' problem solving of a locomotor task, 28 newly walking infants who were within a week of having given up crawling trained to navigate a shoulder-height tunnel to reach a caregiver waiting at the end. During the transitional window between crawling and walking, infants are reluctant to return to crawling, making this task uniquely challenging. Infants were randomly assigned to either nap or stay awake during a delay between training and a later test session. For the Nap group, efficiency of problem solving improved from training to test, but there was no change for the No Nap group. These findings suggest that for newly walking infants, sleep facilitates learning to solve a novel motor problem.

Step by step: a microgenetic study of the development of strategy choice in infancy.

To examine patterns of strategy choice and discovery during problem-solving of a novel locomotor task, 13.5- and 18-month-old infants were placed at the top of a staircase and encouraged to descend. Spontaneous stair descent strategy choices were documented step by step and trial by trial to provide a microgenetic account of problem-solving in action. Younger infants tended to begin each trial walking, were more likely to choose walking with each successive step, and were more likely to lose their balance and have to be rescued by an experimenter. Conversely, older infants tended to begin each trial scooting, were more likely to choose scooting with each successive step, and were more likely to use a handrail to augment balance on stairs. Documenting problem-solving microgenetically across age groups revealed striking similarities between younger infants' strategy development and older children's behaviour on more traditionally cognitive tasks, including using alternative strategies, mapping prior experiences with strategies to a novel task, and strengthening new strategies. As cognitive resources are taxed during a challenging task, resources available for weighing alternatives or inhibiting a well-used strategy are reduced. With increased motor experience, infants can more easily consider alternative strategies and maintain those solutions over the course of the trial.

What Cruising Infants Understand about Support for Locomotion.

"Cruising" infants can only walk using external support to augment their balance. We examined cruisers' understanding of support for upright locomotion under four conditions: cruising over a wooden handrail at chest height, a large gap in the handrail, a wobbly unstable handrail, and an ill positioned low handrail. Infants distinguished among the support properties of the handrails with differential attempts to cruise and handrail-specific forms of haptic exploration and gait modifications. They consistently attempted the wood handrail, rarely attempted the gap, and occasionally attempted the low and wobbly handrails. On the wood and gap handrails, attempt rates matched the probability of cruising successfully; but on the low and wobbly handrails, attempt rates under- and over-estimated the probability of success, respectively. Haptic exploration was most frequent and varied on the wobbly handrail, and gait modifications-including previously undocumented "knee cruising"-were most frequent and effective on the low handrail. Results are discussed in terms of developmental changes in the meaning of support.