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In this longitudinal EEG study, we examined the developmental trajectory of the N400 component using a wordpicture mismatch-paradigm in 18 infants at 10 and 12 months of age. Event-related potentials (ERPs) were recorded and analyzed in three consecutive time windows (400-600 ms, 600-800 ms, 800-1000 ms poststimulus). At 10 months, a significant N400-like effect occurred (400-600 ms) but diminished by 12 months, potentially due to developmental changes or increased stimuli familiarity. No significant correlation emerged between N400 amplitude and parental reports of receptive vocabulary. These results imply that the N400 effect is present already in infancy.

The Early Childhood Environment Rating Scale, Third Edition (ECERS-3), is widely used to assess preschool quality. However, concerns remain about its scoring structure, usage in different cultural contexts, and associations with structural quality indicators. This study explored the factor structure of the ECERS-3 and its relationship with teacher education, child-to-adult ratio, group size, and preschool size in 71 Swedish municipal preschools. Confirmatory factor analysis showed poor fit for both the single-factor modeland the original six-subscale structure. Exploratory factor analysis identified a better-fitting four-factor structure: Learning & Play Environment, Interactions & Order, Gross Motor, and Care & Hygiene. We further investigated whether adopting this revised factor structure influenced relationships between ECERS-3 dimensions and structural quality indicators. Analyses of associations with structural quality indicators showed that smaller group sizes were linked to higher quality in Gross Motor activities. Among preschools with group sizes below 15 children, smaller groups were also associated with higher quality in Learning & Play Environment, Care & Hygiene, and overall ECERS-3 scores. Pedagogical and interactional dimensions showed limited or inconsistent relationships with structural variables. Future research should carefully consider how ECERS-3 scores are analyzed and be mindful of potential threshold effects when exploring associations with structural quality.

In late infancy and early toddlerhood, joint attention ability is widely recognized as a crucial foundation for children's vocabulary development, though the exact nature of its contribution remains debated. This study investigates associations between joint attention and subsequent vocabulary development, as well as the possible moderating role of supportive parental behaviors. Seventy children and their families participated in this longitudinal study, which began when the children were 10 months of age. Parents completed the Swedish Communicative Development Inventory (CDI) at four age points (10, 12, 18, and 24 months) to assess receptive and expressive vocabulary growth. Children participated in lab-based assessment of joint attention abilities at 10, 12, and 18 months. Additionally, at 10 and 12 months, parent-child dyads participated in two semi-structured lab assessments to evaluate the quality of parental supportive behaviors during interactions with their child. Primary analysis showed no significant effects of joint attention on subsequent receptive and expressive vocabulary. However, a significant interaction was found between a child's ability to respond to joint attention cues and parental supportive behaviors on receptive vocabulary. These findings indicate that parental supportive behaviors play a crucial role in promoting the development of children's receptive vocabulary.

Background

Extensive research suggests that peripartum depression is a risk factor for children's early language development. Yet, previous research on this association shows mixed results, often lacking information on the persistence of depression and the social context. This population-based cohort study addresses this gap by investigating the longitudinal influence of peripartum depressive symptoms on toddlers' expressive language. Specifically, we systematically examined the influences of timing, severity, and persistence of depressive symptoms during pregnancy and the first 6 months postpartum on child expressive language development, while accounting for important social and environmental factors.

Methods

This study is part of a prospective, population-based investigation conducted within the follow-up Uppsala Birth Cohort study in Uppsala, Sweden. The final analysis included 2176 mother-infant dyads (1122 boys, mean age = 18.3 months, SD = 0.7). Perinatal depressive symptoms were assessed at gestational weeks 17 and 32 and at postpartum six weeks and six months, using the Edinburgh Postnatal Depression Scale (cut-off >12). At 6 months postpartum, mothers were also invited to fill out the Postnatal Bonding Difficulty Questionnaire. At 18 months postpartum, mothers completed the Language Development Survey, which assessed expressive vocabulary and word combinations. Multivariable linear regression models were applied to examine the associations between peripartum depressive symptoms and child language development. Adjusted models incorporated background and social context variables to account for potential confounding factors.

Results

Depressive symptoms during prenatal and postnatal periods were not significantly associated with language outcomes. Our final model identified negative associations with second-born status, family history of late talkers, countryside residence, and maternal age at childbirth. Positive correlations were found for sex (girl) and pregnancy length. The final model explained 8.4% of the variance (F(22, 1566) = 6.525, p < 0.001). Furthermore, we found that persistent depressive symptoms were not significantly related to language outcomes (Kruskal-Wallis test: H = 2.227, df = 2, p = 0.21).

Conclusions

Our findings found no negative link between peripartum depressive symptoms and expressive language in toddlers, even after considering timing, severity, and persistence. While no immediate direct negative influence of peripartum depressive symptoms was observed, the long-term cumulative effects later in life remain unclear

Previous research suggests that early word recognition is an important foundation for subsequent vocabulary development. However, the optimal method for assessing this ability in infancy remains unclear. To investigate this issue, we collected data from 70 participants (45.7% female) at 10, 11.5, 18 and 24 months of age using two eye-tracking based tasks—the preferential looking- and mismatch paradigms—as well as parental reports on a short form of the Swedish Early Communicative Development Inventories (SE-CDI). Both eye-tracking-based paradigms correlated with concurrent and later vocabulary scores. However, while the preferential looking paradigm showed stability across time, the mismatch paradigm did not demonstrate longitudinal stability and its associations with vocabulary were sometimes in unexpected directions. These findings suggest that the mismatch paradigm may reflect shifting cognitive or attentional processes during development, highlighting the need for further investigation. In contrast, the eye-tracking based preferential looking paradigm, may offer an objective complement to parental reports for predicting subsequent vocabulary development in early childhood.

Gaze following in infancy allows triadic social interactions and a comprehension of other individuals and their surroundings. Despite its importance for early development, its ontology is debated, with theories suggesting that gaze following is either a universal core capacity or an experience-dependent learned behavior. A critical test of these theories among 809 nine-month-olds from Africa (Uganda and Zimbabwe), Europe (Sweden), and Asia (Bhutan) demonstrated that infants follow gaze to a similar degree regardless of environmental factors such as culture, maternal well-being (postpartum depression, well-being), or traumatic family events (related to war and/or climate change). These findings suggest that gaze following may be a universal, experience-expectant process that is resilient to adversity and similar across a wide range of human experiences-a core foundation for social development.

Early childhood educators’ math anxiety and its relation to their frequency of pedagogic actions was examined through a questionnaire completed by 352 participants (aged 21–65) representative of the Swedish municipality where the study was conducted. Our sample contained 189 certified preschool teachers and 163 preschool caregivers who significantly differed in their ratings reported for math teaching anxiety. Results revealed that certified preschool teachers who reported higher levels of math anxiety also reported teaching and talking about mathematics content less frequently. When controlling for certified preschool teachers’ gender and age, years of work in preschools, and whether they work only with younger (1–3), older (4–6) or with both groups of children (1–6-year-old), certified preschool teachers’ general math anxiety and math teaching anxiety predicted their reported frequency of math teaching and frequency of conversations about numbers, patterns, and geometric concepts with peak strength in gatherings, excursions and situations designed to teach mathematics to preschool children. Preschool caregivers’ math anxiety measures and their reported frequency of pedagogic actions did not display statistically significant relations. Findings showed setting specific associations between certified preschool teachers general math anxiety, math teaching anxiety and their avoidance of mathematics content, highlighting the importance of early childhood educators’ awareness of math anxiety, its nature, and consequences for teaching practices.

How do children construct a concept of natural numbers? Past research addressing this question has mainly focused on understanding how children come to acquire the cardinality principle. However, at that point children already understand the first number words and have a rudimentary natural number concept in place. The question therefore remains; what gets children's number learning off the ground? We therefore, based on previous empirical and theoretical work, tested which factors predict the first stages of children's natural number understanding. We assessed if children's expressive vocabulary, visuospatial working memory, and ANS (Approximate number system) acuity at 18 months of age could predict their natural number knowledge at 2.5 years of age. We found that early expressive vocabulary and visuospatial working memory were important for later number knowledge. The results of the current study add to a growing body of literature showing the importance of language in children's learning about numbers.