Infant and Child Development最新文献

When children are aged around 2 years, many of the early foundations of mathematical skills are developing. Understanding this is important to shed light on theories of mathematical development. Nevertheless, little research has investigated 2-year-olds' early mathematical abilities, with most research focussing on either infants (aged 0–1 years) or pre-schoolers (aged 3–5 years). One possible reason for this lack of research may be the challenges associated with the methods used with this age group. Here, we review the methods used to assess 2-year-olds' basic mathematical skills and identify the gaps and issues with those methods. Our findings indicate several issues, both with individual methods used to test specific skills but also some common challenges applicable across all measures and skills. We discuss the identified issues and highlight a need for more appropriate approaches and for alternative methods of administration to better evaluate 2-year-olds' mathematical skills.

Codeswitching is a common feature of bilingual language practices, yet its impact on word learning is poorly understood. Critically, processing costs associated with codeswitching may extend to learning. Moreover, verbs tend to be more difficult to learn than nouns, and the challenges of learning verbs could compound with processing costs associated with codeswitching. In two Experiments, we taught 4–5-year-old bilingual children verbs (Experiment 1, N = 25, 13 girls, 69% white, 83% Hispanic) and nouns (Experiment 2, N = 29, 12 girls, 72% while, 68% Hispanic) within English-only and Spanish-English codeswitched learning contexts. Children's language ability across Spanish and English was modeled continuously, allowing us to test the impact of language ability on learning. Children learned novel words successfully in both experiments, with no difference between conditions. However, children with higher language ability demonstrated steeper learning rates l in the English-only condition relative to the codeswitched condition in both Experiment 1 (standardized coefficient of 0.19) and Experiment 2 (standardized coefficient of 0.14). Our findings indicate that bilingual children can successfully learn both verbs and nouns in codeswitched contexts but learning is modulated by a child's language skills as well as the number of learning opportunities they have had.

While studies have documented neural correlates of language delay in toddlers with developmental conditions, those at genetic risk for language delay, and those born premature, no studies have examined neural correlates in toddlers exhibiting early language delay without known aetiology. This study examines brain morphometry in toddlers with and without early language delay. To do so, we collected magnetic resonance imaging (MRI) on toddlers with language delay (LD; n = 7, M_age = 19.67 months, 3 female, 2 Hispanic and 4 non-caucasian) and a typically developing (TD; n = 17, M_age = 22.73 months, 8 female, 2 Hispanic and 3 non-caucasian) comparison group. Exploratory analyses examined group differences in total brain volume, cortical thickness and cortical surface area using both a whole-brain and region of interest (Broca's and Wernicke's areas) approach. Results showed no gross brain anatomical differences between groups. However, there were group differences in cortical surface area in the temporal cortex (including Wernicke's area and left middle temporal gyrus, hedges' g = − 0.35) and Broca's area thickness. Results are reported using multiple analytic methods, age matching and exclusion of children later diagnosed with autism. While this exploratory study has a limited sample size, it provides novel findings that can be utilised to guide hypothesis-driven imaging studies on toddler language delay.

To address the need for interventions targeting social emotional development and mental health of young children in South Africa, the Mazi Umntanakho (‘know your child’) digital tool was co-designed, and piloted with caregivers and 3–5-year-old children involved in home visiting programmes promoting early childhood development. The aim of this study was to qualitatively evaluate the feasibility and acceptability of this tool in four urban and four rural low-income communities, from the perspective of home visitors and caregivers. Focus groups were conducted with home visitors (n = 117) and caregivers (n = 72). Issues relating to the feasibility of implementing the tool included timing of using the tool, technical and social implementation challenges, WhatsApp as the preferred platform, and participants' recommendations for future implementation. Overall, the tool was acceptable for home visitors and caregivers and was perceived to have a positive impact on children's development, and the relationship between caregivers and children.

Cognitive tasks are seldom evaluated on their ability to provide valid and reliable measurements of the construct they intend to measure. This scarcity of psychometric evaluations makes it challenging to evaluate replications of experimental effects and to relate performance in cognitive tasks to other constructs of interest. In developmental science, these issues are compounded by the often-imprecise measures derived from tasks completed by child participants. Here, we focus on the spatial arrangement method when used to assess semantic structure in children and evaluate its psychometric properties. Using a new analytic approach to capture individual variability in participants' arrangement in this task, we show that the spatial arrangement method has appropriate construct validity (β = 0.40), internal consistency (r² = 0.20), and test–retest reliability (r² = 0.41; ICC = 0.56) when used to evaluate semantic structure in U.S. children (4–9 years of age; N = 200 across 4 datasets). We discuss the implications of these findings for examining semantic structure in children and for strengthening methodological practices in developmental science more broadly.

Twin studies are important for research on genetic and environmental influences on child development, but it is imperative to test whether findings can be generalised from twins to singletons. Since the first months of life are defined by the emergence of important sleep behaviours, we compared 451 (54.8% females) twins and 77 singletons (48.1% females) on a range of sleep, settle and crying behaviours at 5 months of age. No significant differences were found regarding duration of crying or time until settled. However, singletons were reported to wake up more frequently during nighttime than twins (F(1, 509) = 35.10, p < 0.001, η_p² = 0.065), suggesting that, when reported in twin studies, this measure might be slightly underestimated at a mean level in relation to singletons. In conclusion, despite the unique challenges and additional caregiver load of infant twins, there seem to be few differences between twins and singletons regarding parent-reported settle and crying behaviours in early infancy.

The parasympathetic nervous system (PNS) is highly responsive to changes in environmental conditions and serves an essential role in mobilising the metabolic resources required for young children to regulate their thoughts, emotions and behaviours. According to polyvagal theory, the PNS evolved to play a leading role in the neurophysiological response to situations that range from modestly challenging to engaging, and many situations in which young children must exercise volitional processes of self-regulation conform to this description. Children's phasic parasympathetic activity during measures of volitional self-regulation is often associated with their performance on those measures or with their performance on other assessments of self-regulation, but the nature of the associations between PNS activity and performance on measures of volitional self-regulation is highly variable. This heterogeneity complicates the interpretation of results obtained across different studies and inhibits our ability to formulate directional hypotheses about what patterns of phasic parasympathetic activity we would expect to observe as young children exercise volitional processes of self-regulation in different situations. This special issue presents a set of papers that addressed these challenges by administering multiple measures of volitional self-regulation to the same sample of children or by examining how children's characteristics and experience in their developmental environments may account for observed differences in their phasic PNS activity.

Parasympathetic nervous system (PNS) activity has widespread research applications but poses measurement challenges due to its high sensitivity to environmental conditions and immediate demands. While standardised methods exist for measuring PNS reactivity and recovery in response to stressors, the selection of appropriate baseline and resting states is often overlooked. This commentary argues that a clearer conceptual distinction between baseline, a research construct for comparing values, and rest, a psychophysiological state of low arousal and cognitive engagement, is crucial for data interpretation. This includes a need for explicitly justifying baseline conditions in relation to research goals and validating rest conditions. By improving the clarity and rigour of baseline and rest, researchers can enhance the interpretability of PNS reactivity and recovery measures, supporting integration of research findings across studies.