Ten lessons about infants' everyday experiences

Mothers speak less to infants during detected real-world phone use

The current study is the first to document the real-time association between phone use and speech to infants in extended real-world interactions. N= 16 predominantly White (75%) mother-infant dyads (infants aged M = 4.1 months, SD = 2.3; 63% female) shared 16,673 min of synchronized real-world phone use and Language Environment Analysis audio data over the course of 1 week (collected 2017-2020) for our analyses. Maternal phone use was associated with a 16% decrease in infants' speech input, with shorter intervals of phone use (1-2 min) associated with a greater 26% decrease in speech input relative to longer periods. This work highlights the value of multimodal sensing to access dynamic, within-person, and context-specific predictors of speech to infants in real-world settings.

Natural-ish behavior: The interplay of culture and context in shaping motor behavior in infancy

What is natural behavior and how does it differ from laboratory-based behavior? The "natural" in natural behavior implies the everyday, complex, ever-changing, yet predictable environment in which children grow up. "Behavior" is motor action and is foundational to psychology, as it includes all things to function in everyday environments. Is behavior demonstrated in the laboratory un-natural? Suppose behavior emerges spontaneously, in a context that is most common to the animal but an observer is there to document it using particular research tools. Is that behavior natural or natural-ish? Methods can powerfully affect conclusions about infant experiences and learning. In the lab, tasks are typically narrowly constrained where infants and children have little opportunity to display the variety of behaviors in their repertoire. Data from naturalistic observations may paint a very different picture of learning and development from those based on structured tasks, exposing striking variability in the environment and behavior and new relations between the organism and its environment. Using motor development as a model system, in this chapter we compare frameworks, methods, and findings originating in the lab and in the field, applied and adapted in different settings. Specifically, we recount our journey of pursuing the study of cultural influences on motor development in Tajikistan, and the challenges, surprises, and lessons learned.

Variations in infants' physical and social environments shape spontaneous locomotion

Independent locomotion is associated with a range of positive developmental outcomes, but unlike cognitive, linguistic, and social skills, acquiring motor skills requires infants to generate their own input for learning. We tested factors that shape infants' spontaneous locomotion by observing forty 12- to 22-month-olds (19 girls, 21 boys) during free play. Infants were recruited from the New York City area, and caregivers reported that 25 infants were White, six were Asian, four were Black, and five had multiple races; four were Hispanic or Latino. All infants played in four conditions: two environmental conditions (gross-motor toys, fine-motor toys) crossed with two social conditions (alone, together with a caregiver). Infants moved more in the gross-motor toy conditions than in the fine-motor toy conditions. However, the effect of playing with a caregiver differed by toy condition. In the gross-motor toy conditions, playing with a caregiver did not affect how much infants moved, but in the fine-motor toy conditions, playing with a caregiver further depressed infant locomotion. Infants with more walking experience moved more with gross-motor toys but not with fine-motor toys. Differences in the amount of locomotion between conditions were related to how infants used toys and the interactions between infants and caregivers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Infant-directed communication: Examining the many dimensions of everyday caregiver-infant interactions

Everyday caregiver-infant interactions are dynamic and multidimensional. However, existing research underestimates the dimensionality of infants' experiences, often focusing on one or two communicative signals (e.g., speech alone, or speech and gesture together). Here, we introduce "infant-directed communication" (IDC): the suite of communicative signals from caregivers to infants including speech, action, gesture, emotion, and touch. We recorded 10 min of at-home play between 44 caregivers and their 18- to 24-month-old infants from predominantly white, middle-class, English-speaking families in the United States. Interactions were coded for five dimensions of IDC as well as infants' gestures and vocalizations. Most caregivers used all five dimensions of IDC throughout the interaction, and these dimensions frequently overlapped. For example, over 60% of the speech that infants heard was accompanied by one or more non-verbal communicative cues. However, we saw marked variation across caregivers in their use of IDC, likely reflecting tailored communication to the behaviors and abilities of their infant. Moreover, caregivers systematically increased the dimensionality of IDC, using more overlapping cues in response to infant gestures and vocalizations, and more IDC with infants who had smaller vocabularies. Understanding how and when caregivers use all five signals-together and separately-in interactions with infants has the potential to redefine how developmental scientists conceive of infants' communicative environments, and enhance our understanding of the relations between caregiver input and early learning. RESEARCH HIGHLIGHTS: Infants' everyday interactions with caregivers are dynamic and multimodal, but existing research has underestimated the multidimensionality (i.e., the diversity of simultaneously occurring communicative cues) inherent in infant-directed communication. Over 60% of the speech that infants encounter during at-home, free play interactions overlap with one or more of a variety of non-speech communicative cues. The multidimensionality of caregivers' communicative cues increases in response to infants' gestures and vocalizations, providing new information about how infants' own behaviors shape their input. These findings emphasize the importance of understanding how caregivers use a diverse set of communicative behaviors-both separately and together-during everyday interactions with infants.

Referent-oriented interactions in infancy: A naturalistic, longitudinal case study from an English-speaking household

Caregivers use a of combination labeling, pointing, object grasping, and gaze to communicate with infants about referents in their environment. By two years of age, children reliably use these referent-oriented cues to communicate and learn. While there is some evidence from lab-based studies that younger infants attend to and use referent-oriented cues during communication, some more naturalistic studies have found that in the first year of life, infants do not robustly leverage these cues during dyadic interactions. The current study examined parent and infant gaze, touching, pointing, and reaching to referents for a wide range of nouns, verbs, adjectives, and other early-learned words during 59 one-hour head-camera recordings sampled from one English-learning infants' life between 6 and 12 months of age. We found substantial variability across individual words for all cues. Some variability was explained by referent concreteness and the grammatical category of the label. The parent's touching of labeled referents increased across months, suggesting that parent-infant-referent interactions may change with development. Future studies should investigate the trajectories of specific types of words and contexts, rather than attempting to discover possibly non-existent universal trajectories of parent and infant referent-oriented behaviors.

Caregiving relationships are a cornerstone of developmental psychopathology

The interdisciplinary field of developmental psychopathology has made great strides by including context into theoretical and empirical approaches to studying risk and resilience. Perhaps no context is more important to the developing child than their relationships with their caregivers (typically a child's parents), as caregivers are a key source of stimulation and nurturance to young children. Coupled with the high degree of brain plasticity in the earliest years of life, these caregiving relationships have an immense influence on shaping behavioral outcomes relevant to developmental psychopathology. In this article, we discuss three areas within caregiving relationships: (1) caregiver-child interactions in everyday, naturalistic settings; (2) caregivers' social cognitions about their child; and (3) caregivers' broader social and cultural context. For each area, we provide an overview of its significance to the field, identify existing knowledge gaps, and offer potential approaches for bridging these gaps to foster growth in the field. Lastly, given that one value of a scientific discipline is its ability to produce research useful in guiding real-world decisions related to policy and practice, we encourage developmental psychopathology to consider that a focus on caregiving, a modifiable target, supports this mission.

The everyday speech environments of preschoolers with and without cochlear implants

Children who receive cochlear implants develop spoken language on a protracted timescale. The home environment facilitates speech-language development, yet it is relatively unknown how the environment differs between children with cochlear implants and typical hearing. We matched eighteen preschoolers with implants (31-65 months) to two groups of children with typical hearing: by chronological age and hearing age. Each child completed a long-form, naturalistic audio recording of their home environment (appx. 16 hours/child; >730 hours of observation) to measure adult speech input, child vocal productivity, and caregiver-child interaction. Results showed that children with cochlear implants and typical hearing were exposed to and engaged in similar amounts of spoken language with caregivers. However, the home environment did not reflect developmental stages as closely for children with implants, or predict their speech outcomes as strongly. Home-based speech-language interventions should focus on the unique input-outcome relationships for this group of children with hearing loss.

Auditory chaos classification in real-world environments

Background & motivation

Household chaos is an established risk factor for child development. However, current methods for measuring household chaos rely on parent surveys, meaning existing research efforts cannot disentangle potentially dynamic bidirectional relations between high chaos environments and child behavior problems.

Proposed approach

We train and make publicly available a classifier to provide objective, high-resolution predictions of household chaos from real-world child-worn audio recordings. To do so, we collect and annotate a novel dataset of ground-truth auditory chaos labels compiled from over 411 h of daylong recordings collected via audio recorders worn by N = 22 infants in their homes. We leverage an existing sound event classifier to identify candidate high chaos segments, increasing annotation efficiency 8.32× relative to random sampling.

Result

Our best-performing model successfully classifies four levels of real-world household auditory chaos with a macro F1 score of 0.701 (Precision: 0.705, Recall: 0.702) and a weighted F1 score of 0.679 (Precision: 0.685, Recall: 0.680).

Significance

In future work, high-resolution objective chaos predictions from our model can be leveraged for basic science and intervention, including testing theorized mechanisms by which chaos affects children's cognition and behavior. Additionally, to facilitate further model development we make publicly available the first and largest balanced annotated audio dataset of real-world household chaos.

Gross motor trajectories of pre-term and full-term infants under different parental educational approaches

This study aimed to explore motor trajectories of Brazilian pre-term and full-term infants from 3 to 12 months old whose parents participated in an educational program and had received guidance on gross motor development. Forty-eight Brazilian infants aged 3 months old were divided into Group 1 (full-term infants and their parents who received only verbal guidance, n = 14), Group 2 (full-term infants with parents who received an educative folder in addition to the same verbal guidance, n = 23), and Group 3 (preterm infants with parents who received the same verbal guidance and educative folder, n = 11). The folder had similar information to the verbal guidance; nonetheless, it helped to teach parents and allowed later consultation at home. We applied Alberta Infant Motor Scale, Affordances in Home Environment for Motor Development-Infant Scale, and a questionnaire about infants' information at 3-, 6-, 9-, and 12-months old. In longitudinal comparison, all groups showed a significant difference for AIMS variables on total score and subscales; all subitems of AHEMD-IS; and time spent in prone, supine, sitting, and standing positions. In general, no differences were found between groups. Motor trajectory, home opportunities, and parental positioning practices were similar between full-term and preterm infants with different guidance approaches.

Long-form recording of infant body position in the home using wearable inertial sensors

Long-form audio recordings have had a transformational effect on the study of infant language acquisition by using mobile, unobtrusive devices to gather full-day, real-time data that can be automatically scored. How can we produce similar data in service of measuring infants' everyday motor behaviors, such as body position? The aim of the current study was to validate long-form recordings of infant position (supine, prone, sitting, upright, held by caregiver) based on machine learning classification of data from inertial sensors worn on infants' ankles and thighs. Using over 100 h of video recordings synchronized with inertial sensor data from infants in their homes, we demonstrate that body position classifications are sufficiently accurate to measure infant behavior. Moreover, classification remained accurate when predicting behavior later in the session when infants and caregivers were unsupervised and went about their normal activities, showing that the method can handle the challenge of measuring unconstrained, natural activity. Next, we show that the inertial sensing method has convergent validity by replicating age differences in body position found using other methods with full-day data captured from inertial sensors. We end the paper with a discussion of the novel opportunities that long-form motor recordings afford for understanding infant learning and development.

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.

Everyday Parameters for Episode-to-Episode Dynamics in the Daily Music of Infancy

Experience‐dependent change pervades early human development. Though trajectories of developmental change have been well charted in many domains, the episode‐to‐episode schedules of experiences on which they are hypothesized to depend have not. Here, we took up this issue in a domain known to be governed in part by early experiences: music. Using a corpus of longform audio recordings, we parameterized the daily schedules of music encountered by 35 infants ages 6–12 months. We discovered that everyday music episodes, as well as the interstices between episodes, typically persisted less than a minute, with most daily schedules also including some very extended episodes and interstices. We also discovered that infants encountered music episodes in a bursty rhythm, rather than a periodic or random rhythm, over the day. These findings join a suite of recent discoveries from everyday vision, motor, and language that expand our imaginations beyond artificial learning schedules and enable theorists to model the history‐dependence of developmental process in ways that respect everyday sensory histories. Future theories about how infants build knowledge across multiple episodes can now be parameterized using these insights from infants’ everyday lives.