We compared maternal speech in interactions of mothers with their firstborn dizygotic twin and singleton infants. Nine twins and nine singletons were video-recorded at home in spontaneous face-to-face interactions with their mothers, from the 2nd to the 6th month. Continuous micro-analysis revealed that there are more quantitative and qualitative…

This study explores how 7-month-old infants categorize graphical images varying in basic perceptual features by using a fast periodic visual stimulation (FPVS) task. Most participants were Caucasian and their parents had a higher education, but the family's socioeconomic background was mixed. Experiment 1 (N = 23) tested brain responses to…

Previous studies found an impact of language familiarity on face recognition in 9- and 12-month-olds. Own race faces are better recognized when associated with native language, whereas for other race faces, it is with non-native language. The aim of this study is to investigate if language familiarity can also influence abstract pattern…

Infants are born highly sensitive to the natural patterns found in languages. They use their perceptual sensitivity to acquire detailed information about the structure of languages in their environment. To date, most studies of infant perception and early language acquisition have investigated spoken/auditory languages and hearing infants (e.g.…

Fourteen-month-olds selectively imitated a sub-efficient means (illuminating a lightbox by a head-touch) when this was modeled by linguistic ingroup members in video-demonstrations. A follow-up study with slightly older infants, however, could replicate this effect only in a video-demonstration context. Hence it still remains unclear whether…

Aim: To investigate developmental trajectories in early childhood and predictors of class assignment. Methods: Data were available for Gen2 infants at 12 (n = 2275), 24 (n = 1845) and 36 (n = 2110) months of age in the Raine Study. Latent growth class analysis was used to identify developmental trajectories based on the Ages and Stages…

Over the last 2 centuries there has been a rapid increase in the proportion of children who grow up in cities. However, relatively little work has explored in detail the physiological and cognitive pathways through which city life may affect early development. To assess this, we observed a cohort of infants growing up in diverse settings across…

Detecting developmental delays is essential for early intervention in low to middle-income countries. A cross-sectional, within-subject, comparative design was employed to determine the performance of the Parents Evaluation of Developmental status (PEDS) tools smartphone application and the Bayley Scales of Infant and Toddler Development III (BSID…

Infant-directed speech (IDS) is characterized by a range of register-typical characteristics. Many of those can be objectively measured, such as acoustic-prosodic and structural-linguistic modifications. Perceived vocal affect, however, is a socio-emotional IDS characteristic and is subjectively assessed. Vocal affect goes beyond acoustic-prosodic…

The aim of this study was to determine the effectiveness of follow-up care and health counselling provided by midwives and nurses in maternal-infant attachment level and relationships between sociodemographic factors. The study was designed as a quasi-experimental pattern with a control group on pretest-posttest. The sample size was determined…

Although both fathers and mothers speak differently in infant-directed speech (IDS) compared to adult-directed speech (ADS), the acoustic characteristics of present-day paternal IDS are still insufficiently understood. To extend this understanding, 11 fathers and 17 mothers in The Netherlands were recorded interacting with their infant…

Evidence shows individual variation in lexical acquisition as a function of socioeconomic status and linguistic input. Research has primarily involved English-speaking populations and considered only mothers' child-directed speech. This study analyzes the effects of socioeconomic status on quantitative and qualitative properties of linguistic…

Fifty-one 23-to-55-month-old-infants faced two apparatuses that required the use of a rigid (box apparatus) or flexible (hose apparatus) stick-like tool to retrieve a toy stuck inside. Before attempting the extraction, however, they had to pick the only one tool (of three) on display that had the appropriate rigidity/flexibility to be effective.…

Very early precursors of disrupted social behaviours are significant to understanding the possibility of mitigating or changing behaviours through interventions. Spontaneous play situations between infant and parent in two groups of infants aged 8.5-9 months were observed. First, a large number of videos were analysed to develop an observational…

This is the first large-scale study of resources as a form of "language management" -- that is, a way of influencing children's language practices. We introduce the distinction between child-directed resources (i.e. those providing parents with opportunities to engage with their children in the languages they are transmitting) and…