Infancy最新文献

Current research indicates likely developmental connections between the evolution of sleep patterns, motor skills progression, and the expansion of vocabulary. These connections are grounded in the well-established role of sleep in memory and learning, as well as in the cascading effects on language development of the acquisition of new motor skills. However, no study has so far undertaken a comprehensive and systematic examination of these connections or explored their developmental trajectory over time. Yet understanding vocabulary development depends on considering development in the sleep regulation and motor domains, to provide a biologically grounded explanation of how early lexicons are built and strengthened. This study investigates the links between vocabulary growth and two significant changes occurring over the first 2 years of life: self-initiated locomotion and the consolidation of overnight sleep. Our results reveal mutual associations between these domains, which tend to emerge during periods of marked developmental change in language, motor skills, and sleep patterns regulation. Moreover, these associations were observed to change over time, suggesting dynamic interconnections between these developmental domains. Our findings point toward the importance of investigating vocabulary development from a dynamic systems perspective, as the product of continuous interactions between cognition, the body and the environment.

The interplay of emotional availability (EA) and child temperament in association with early language development is understudied. We explored associations between maternal EA and infant communicative development and possible moderations by child temperament. Participants were 151 mother-child dyads from the FinnBrain Birth Cohort Study. Path models of associations between 8-month maternal EA and 14-month communicative development and moderation by infant temperament traits were created using SEM. Results show that EA positively predicted a latent variable of communicative development at 14 months. No direct longitudinal effect of EA on 30-month vocabulary was found. Child surgency/extraversion at 6 and 12 months significantly predicted 14-month communicative skills. Temperament did not moderate the association between EA and communicative development. Findings underscore the additive role of maternal caregiving and early surgency/extraversion in predicting early communicative development. The emotional aspects of parenting should be acknowledged as contributors to early communicative development in future studies.

Humans are curious. Especially children are known for their drive to explore and learn, which is crucial for developing in and navigating through our complex world. Naturally, some children may be more curious than others, leading to differences in how they structure their own learning experiences, subsequently impacting their developmental trajectories. However, there is a gap in the research field for a reliable measure of such differences early in development. Across three studies, we present the development and assessment of the Infant and Toddler Curiosity Questionnaire (ITCQ), the first caregiver report measure to fill this gap. Items cover observable exploration behaviors in 5- to 24-month-olds to capture general tendencies of their desire to actively explore their immediate surroundings and are evaluated on a 7-point Likert-scale. Exploratory factor analyses and structural equation modeling on a sample of N = 370 UK caregivers led to the final selection of 23 items and provided evidence that the scale allows the reliable computation of an overall curiosity score, with three emergent subscales (Sensory, Investigative, and Interactive) explaining additional variance in the data. Furthermore, the scale had good test-retest reliability after 7–14 days (N = 67) and related to the child's temperament (N = 75; positively with surgency and effortful control, negatively with negative affect) offering evidence of its validity as a trait measure. Together, these results support the scale's reliability and validity, showcasing the ITCQ as a powerful tool for developmental research.

The ability to recognize and act on others' emotions is crucial for navigating social interactions successfully and learning about the world. One way in which others' emotions are observable is through their movement kinematics. Movement information is available even at a distance or when an individual's face is not visible. Infants have been shown to be sensitive to emotions in movement kinematics of transporting actions, like moving an object from one to another place. However, it is still unknown whether they associate the manipulated object with the emotions contained in moving it, and whether they use this information to guide their own exploration of this object. In this study, 12-month-old infants watched actors transporting two toys with positive or negative emotional valence. Then, infants were given the possibility to interact with the same toys. We expected the infants to look at and touch the toy handled in a positive manner more, compared to the toy handled in a negative manner. Our results showed that infants looked at the positive toys more than at the negative toys, but that infants touched both toys for the same amount of time. Also, there was no difference in which toy they manually explored first.

East Asians are more likely than North Americans to attend to visual scenes holistically, focusing on the relations between objects and their background rather than isolating components. This cultural difference in context sensitivity—greater attentional allocation to the background of an image or scene—has been attributed to socialization, yet it is unknown how early in development it appears, and whether it is moderated by social information. We employed eye-tracking to investigate context-sensitivity in 15-month-olds in Japan (n = 45) and the United States (n = 52). Viewing faces, Japanese infants were more attentive and studied the background longer than U.S. infants. Viewing cartoon videos, Japanese infants looked at the background twice as long as U.S. infants, particularly for objects with eyes. In parent-child book reading, Japanese parents referred to the background significantly more than U.S. parents, although this was uncorrelated with infant behavior on the preceding tasks. These findings illustrated that cultural differences in attention are detectable in infancy, and that sustained attention may be an important foundation upon which culturally-specific attentional styles are built. Overall, results were consistent with the view that a context-sensitive orientation first emerges for social information and later generalizes to non-social situations.

Musical interactions between caregivers and their infants typically rely on a limited repertoire of live vocal songs and recorded music. Research suggests that these well-known songs are especially effective at eliciting engaged behaviors from infants in controlled settings, but how infants respond to familiar music with their caregivers in their everyday environment remains unclear. The current study used an online questionnaire to quantify how often and why caregivers present certain songs and musical recordings to their infants. Using a cross-sectional approach, we explored infants' changing behavioral profiles to music from birth to 24 months. Caregivers additionally reported on their feelings of affective attachment toward their infants. Results reveal that caregivers sing and play recorded music for younger and older infants at comparably high rates. In turn, infants actively respond to their favorite songs and recordings by demonstrating positive emotions, movements, and attentive listening. Caregivers mainly consider their infants' musical preferences when building their shared musical repertoire at home. Both caregivers' engagement in musical activities with their children and infants' enthusiastic responsiveness to singing predicted stronger dyadic attachment bonding. Caregivers and infants jointly contribute to building musical relationships, and these musical relationships may be intertwined with their emerging social-emotional bonds.

Speech and co-speech gestures always go hand in hand. Whether we find the precursors of these co-speech gestures in infants before they master their native language still remains an open question. Except for deictic gestures, there is little agreement on the existence of iconic, non-referential and conventional gestures before children start producing their first words. Here, we bridge this knowledge gap by leveraging an ethological method already established for describing speech independent gestures in nonhuman primates, to analyze the spontaneous gestures produced by infants when interacting with their caregivers. We manually annotated video recordings of infant-caregiver interactions (26 h) from the CHILDES platform, to describe the gesture forms, types and functions in six infants from 12 to 15 months of age. We describe 62 gesture forms in the preverbal repertoire. These were categorized into deictic, iconic, non-referential and conventional gesture types, similar to co-speech gesture types. We also find that the type-function relation of preverbal gestures map similarly to type-meaning relation of co-speech gestures. Taken together, our results illustrate linguistic properties of infant gestures in the absence of speech, suggesting them to be precursors of co-speech gestures.

Assessing early vocabulary development commonly involves parent report methods and behavioral tasks like looking-while-listening. While both yield reliable aggregate scores, findings are mixed regarding their reliability in measuring infants' knowledge of individual words. Using archival data from 126 monolingual and bilingual 14–31-month-olds, we further examined links across these methods at the word level, while controlling for potentially confounding child-level factors. When data were averaged at the child level, performance on the looking-while-listening task correlated well with parent-reported word production of the same words, as expected. However, mixed-effects model comparisons suggested that at the word level, looking-while-listening performance was significantly predicted by age and total productive vocabulary, but not by parent-reported knowledge of a word once these factors were controlled for. These findings invite careful consideration regarding the adequacy of these two popular methods for capturing children's idiosyncratic knowledge of individual words.