Infancy最新文献

The current study examined longitudinal associations between early screen media exposure (assessed at 6, 12, and 24 months) and the child's motor and language/communication development at the ages of 24 and 36 months. We also aimed to study whether these associations varied by socioeconomic status (SES). Participants were 179 parent-infant dyads, recruited from well-baby clinic services during routine visits. Child development measures included standardized measures of developmental milestones as assessed by professionals and referral data to child developmental centers. Both measures were retrieved from the official health maintenance organization records by an expert in child development. Results indicated that screen exposure at 6 and 12 months was associated with a higher risk for language/communication deficits at 36 months in children with moderate or high SES but not in children with low SES. Our findings are consistent with existing literature demonstrating cross-sectional and longitudinal associations between early screen exposure and language development deficits. Given that media use practices and motivations vary among families from different backgrounds, further investigation of the interaction between SES and screen exposure is needed.

Media use during childhood has quickly become a norm across the United States and in other countries. One area still not well understood is the development of problematic (or maladaptive and disruptive) media use in children. This research examines the role of attachment security as a central component in the development of problematic media use over time in a sample of 248 parent-child dyads (9.50% African American, 20.66% Hispanic, 62.81% White, 2.07% Asian, 4.96% other ethnicities). We examined the relationship between attachment security and problematic media use one and 2 years later. We then constructed a mediation model examining parent responsiveness while jointly engaging in media use and during play as mediators between infant attachment security and problematic media use over time. Results suggest that while infant attachment security may be protective against developing problematic media use patterns, this relationship does not seem to be mediated by parent-child interactions while engaging in media or during play.

Studies examining infant cradling have almost uniformly concluded with a general human left-side bias for cradling, indicating that people prefer to hold an infant to the left of their body. Explanations for the notion of the left-side cradling bias have traditionally been searched for in a variety of factors, for example, in terms of maternal heartbeat, genetic factors, in the form of an ear asymmetry where auditory information is perceived faster through the left ear, as a result of a right hemispheric functional specialization for perception of emotions and faces, and in identifying a motor bias of the infant, such as the tendency of newborn infants to lie with the face to the right when placed supine. Interestingly, handedness is generally considered an inadequate explanation for the lateralized cradling bias, despite it being an intuitively plausible one. In this brief review, I put forward the cradler's handedness as the most convincing and elegant determinant of the cradling bias. This explanation is consistent with a developmental cascades' framework where the cradling bias can be understood as the result of a multitude of factors across a range of levels and systems.

There is little systematically collected quantitative empirical data on how much linguistic input children in small-scale societies encounter, with some estimates suggesting low levels of directed speech. We report on an ecologically-valid analysis of speech experienced over the course of a day by young children (N = 24, 6–58 months old, 33% female) in a forager-horticulturalist population of lowland Bolivia. A permissive definition of input (i.e., including overlapping, background, and non-linguistic vocalizations) leads to massive changes in terms of input quantity, including a quadrupling of the estimate for overall input compared to a restrictive definition (only near and clear speech), while who talked to and around a focal child is relatively stable across input definitions. We discuss implications of these results for theoretical and empirical research into language acquisition.

The origin of face or language influences infants' perceptual processing and social learning behavior. However, it remains unclear how infants' social learning behavior is affected when both information are provided simultaneously. Hence, the current study investigated whether and how infants' social learning in terms of gaze following is influenced by face race and language origin of an interaction partner in an uncertain situation. Our sample consisted of 91 Caucasian infants from German speaking families. They were divided into 2 age groups: Younger infants were 5- to 8-month-old (n = 46) and the older infants 11- to 20-month-old (n = 45). We used a modified online version of the gaze following paradigm by Xiao and colleagues by varying face race (Caucasian, and Asian faces) and language (German and French) of a female actor. We recorded infants looking behavior via webcam and coded it offline. Our results revealed that older but not younger infants were biased to follow the gaze of own-race adults speaking their native language. Our findings show that older infants are clearly influenced by adults' ethnicity and language in social learning situations of uncertainty.

Research on infant and toddler reaching has shown evidence for motor planning after the initiation of the reaching action. However, the reach action sequence does not begin after the initiation of a reach but rather includes the initial visual fixations onto the target object occurring before the reach. We developed a paradigm that synchronizes head-mounted eye-tracking and motion capture to determine whether the latency between the first visual fixation on a target object and the first reaching movement toward the object predicts subsequent reaching behavior in toddlers. In a corpus of over one hundred reach sequences produced by 17 toddlers, we found that longer fixation-reach latencies during the pre-reach phase predicted slower reaches. If the slowness of an executed reach indicates reach difficulty, then the duration of pre-reach planning would be correlated with reach difficulty. However, no relation was found with pre-reach planning duration when reach difficulty was measured by usual factors and independent of reach duration. The findings raise important questions about the measurement of reach difficulty, models of motor control, and possible developmental changes in the relations between pre-planning and continuously unfolding motor plans throughout an action sequence.

Since birth, infants discriminate the biological motion (BM) revealed by point-light displays (PLDs). To date, no studies have explored whether newborns differentiate BM that approaches rather than withdraws from them. Yet, approach and withdrawal are two fundamental motivations in the socio-emotional world, key to developing empathy and prosocial behavior. Through a looking-behavior paradigm, we demonstrated that a few hours after birth, a human figure approaching attracted more visual attention than a human figure receding, showing that newborns are attuned to PLDs of others moving toward rather than walking away from them. Further, a withdrawing body appears to be less attractive than withdrawing scrambled points. Altogether, these observations support the existence of an early predisposition toward social closeness that might have its roots in an evolutionary perspective.

Measuring eye movements remotely via the participant's webcam promises to be an attractive methodological addition to in-person eye-tracking in the lab. However, there is a lack of systematic research comparing remote web-based eye-tracking with in-lab eye-tracking in young children. We report a multi-lab study that compared these two measures in an anticipatory looking task with toddlers using WebGazer.js and jsPsych. Results of our remotely tested sample of 18-27-month-old toddlers (N = 125) revealed that web-based eye-tracking successfully captured goal-based action predictions, although the proportion of the goal-directed anticipatory looking was lower compared to the in-lab sample (N = 70). As expected, attrition rate was substantially higher in the web-based (42%) than the in-lab sample (10%). Excluding trials based on visual inspection of the match of time-locked gaze coordinates and the participant's webcam video overlayed on the stimuli was an important preprocessing step to reduce noise in the data. We discuss the use of this remote web-based method in comparison with other current methodological innovations. Our study demonstrates that remote web-based eye-tracking can be a useful tool for testing toddlers, facilitating recruitment of larger and more diverse samples; a caveat to consider is the larger drop-out rate.

Effortful control (EC), a self-regulation skill, is associated with long-term developmental outcomes. Music has been associated with infant self-regulation and may be an intervention strategy for enhancing EC during toddlerhood. This investigation included 32 parent-child dyads from a previously conducted randomized controlled trial (RCT). Participants (9-15-months old at baseline) attended either a music enrichment program or a playdate control once a week for 1 year and monthly for an additional year. At age 3, participants completed snack and gift delay effortful control tasks. Groups were compared using one-way ANOVA. We found that participants in the music group had a significantly higher score during snack delay (music mean = 3.47 ± 0.94; control mean = 2.45 ± 1.51; p = 0.03; Cohen's d = 0.84). We did not find a significant group difference for latency to peek (music mean = 39.10 ± 20.10; control mean = 30.90 ± 19.88; p = 0.25; d = 0.57) or latency to touch (music mean = 105.73 ± 417.69; control mean = 98.35 ± 28.84; p = 0.38; d = 0.29) for the gift task. This study provides initial evidence that early participation in a music enrichment program may benefit later development of EC. This study is registered at ClinicalTrials.gov (NCT02936284).

We compared vocabulary sizes in comprehension and production between bilingual toddlers growing up in the United Kingdom (UK) and age-matched UK English monolinguals (12–36 months old) using parent-report vocabulary questionnaires. We found that bilingual toddlers' vocabulary sizes in English were smaller than the vocabulary sizes of their monolingual peers. Notably, this vocabulary gap was not found when groups were compared on conceptual vocabulary in comprehension. Conceptual scoring also reduced the vocabulary gap in production but group differences were still significant. Bilingual toddlers knew more words than monolinguals when words across their two languages were added together, for both comprehension and production. This large total vocabulary size could be attributed to a high proportion of doublets (cross-linguistic word pairs with the same meaning) in bilinguals' vocabularies. These findings are discussed in relation to language exposure, facilitation from cross-linguistic overlap and maturation constraints on vocabulary size.