Associations between observed and reported infant negative affectivity, fear and self-regulation, and early communicative development-Evidence from the FinnBrain Birth Cohort Study

Receptive and expressive vocabulary performance in 2- to 5-year-olds in care: The role of different care types and temperament

The detrimental role of institutionalization in children's development has prompted the introduction of alternative care types designed to offer more personalized care. The current study aimed to test whether children in alternative care types (care villages, care homes, and foster care) performed better on vocabulary than those in institutions. The role of temperament, specifically perceptual sensitivity and frustration, and the interaction between temperament and care types on vocabulary performance were also explored. The study involved 285 2- to 5-year-old children from different care types, and they were assessed through receptive and expressive vocabulary tests and temperament scales. The results of the linear mixed model revealed that children in alternative care types exhibited significantly higher vocabulary scores compared with those in institutions. Moreover, perceptual sensitivity showed a positive association with receptive and expressive vocabulary skills and seemed to act as a protective factor by mitigating the lower vocabulary scores in institutions. Frustration moderated vocabulary outcomes differently for children in institutions and foster care, aligning with the diathesis-stress model and vantage sensitivity theory, respectively. The findings emphasize the positive role of alternative care types in vocabulary performance and the importance of children's temperamental traits in this process.

Sustained pacifier use is associated with smaller vocabulary sizes at 1 and 2 years of age: A cross-sectional study

Pacifier use during childhood has been hypothesized to interfere with language processing, but, to date, there is limited evidence revealing detrimental effects of prolonged pacifier use on infant vocabulary learning. In the present study, parents of 12- and 24-month-old infants were recruited in Oslo (Norway). The sample included 1187 monolingual full-term born (without visual, auditory, or cognitive impairments) infants: 452 (230 girls; 222 boys) 12-month-olds and 735 (345 girls; 390 boys) 24-month-olds. Parents filled out an online Norwegian Communicative Development Inventory (CDI), which assesses the vocabulary in comprehension and production for 12-month-old infants and in production only for 24-month-old infants. CDI scores were transformed into age- and sex-adjusted percentiles using Norwegian norms. Additionally, parents retrospectively reported their child's daytime pacifier use, in hours, at 2-month intervals, from birth to the assessment date. Maternal education was used to control, in the analyses, for the socio-economic status. We found that greater pacifier use in an infant's lifespan was associated with lower vocabulary size. Pacifier use later in life was more negatively associated with vocabulary size than precocious use, and increased the odds of being a low language scorer. In sum, our study moves beyond the findings of momentary effects of experimentally induced "impairment" in articulators' movement on speech perception and suggests that, from 12 months of age, constraints on the infant's speech articulators (pacifier use) may be negatively associated with word comprehension and production. RESEARCH HIGHLIGHT: 1.We examined the relationship between pacifier use and vocabulary sizes in production at 24 months of age and comprehension and production at 12 months of age. 2.Lifespan Pacifier Use (LPU) was negatively correlated with vocabulary sizes in comprehension and production among 12-month-old infants and negatively correlated with production for 24-month-olds. 3.Later pacifier use was found to be more negatively correlated with vocabulary size in infants, as compared to more precocious use. 4.The amount of pacifier use in the 2 months prior to a child's second birthday was predictive of a higher prevalence of low vocabulary scores in 24-month-olds.

Infant gut microbiota and negative and fear reactivity

BACKGROUND

Studies indicate that gut microbiota is related to neurodevelopmental and behavioral outcomes. Accordingly, early gut microbiota composition (GMC) has been linked to child temperament, but research is still scarce. The aim of this study was to examine how early GMC at 2.5 months is associated with child negative and fear reactivity at 8 and 12 months since they are potentially important intermediate phenotypes of later child psychiatric disorders.

METHODS

Our study population was 330 infants enrolled in the longitudinal FinnBrain Birth Cohort Study. Gut microbiota composition was analyzed using stool sample 16s rRNA sequencing. Negative and fear reactivity were assessed using the Laboratory Temperament Assessment Battery (Lab-TAB) at child's age of 8 months (n =150) and the Infant Behavior Questionnaire-Revised Short Form (IBQ-R SF) at child's age of 12 months (n = 276).

CONCLUSIONS

We found a positive association between alpha diversity and reported fear reactivity and differing microbial community composition based on negative reactivity for boys. Isobutyric acid correlated with observed negative reactivity, however, this association attenuated in the linear model. Several genera were associated with the selected infant temperament traits. This study adds to the growing literature on links between infant gut microbiota and temperament informing future mechanistic studies.