Growing up with multiple siblings might negatively affect language development. This study examined the associations between birth order, sibling characteristics and parent-reported vocabulary size in 6163 Norwegian 8- to 36-month-old children (51.4% female). Results confirmed that birth order was negatively associated with vocabulary, yet…

According to the cross-situational learning account, infants aggregate statistical information from multiple parent naming events to resolve ambiguous word-referent mappings within individual naming events. While previous experimental studies have shown that infant and adult learners can build correct mappings based on statistical regularities…

This longitudinal study investigated parents' different pretend play behaviors (substitution, animation, and role enactment) to their infants during free play and the bidirectional links with infants' vocabulary development at 14 months (Time-1: N = 34, M[subscript age] = 14.23 months) and 20 months (Time-2: N = 34, M[subscript age] = 20.33…

The speech register that adults especially caregivers use when interacting with infants and toddlers, that is, infant-directed speech (IDS) or baby talk, has been reported to facilitate language development throughout the early years. However, the neural mechanisms as well as why IDS results in such a developmental faciliatory effect remain to be…

Previous research shows that infants of parents who are more likely to engage in socially contingent interactions with them tend to have larger vocabularies. An open question is "how" social contingency facilitates vocabulary growth. One possibility is that parents who speak in response to their infants more often produce larger…

This systematic review surveyed research on the associations between sleep and the memory processes involved in word learning in infancy. We found only 16 studies that addressed this topic directly, identifying associations between infant sleep and the memory processes, the identification of word forms in running speech, and the stabilization and…

Objectives: The study aimed to investigate the predictive potential of language environment and vocal development status measures obtained through integrated analysis of Language ENvironment Analysis (LENA) recordings during the prelinguistic stage for subsequent speech and language development in Korean-acquiring children. Specifically, this…

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…

Words direct visual attention in infants, children, and adults, presumably by activating representations of referents that then direct attention to matching stimuli in the visual scene. Novel, unknown, words have also been shown to direct attention, likely via the activation of more general representations of naming events. To examine the critical…

The interaction of visual exploration and auditory processing is central to early cognitive development, supporting object discrimination, categorization, and word learning. Research has shown visual-auditory interactions to be complex, created from multiple processes and changing over multiple timescales. To better understand these interactions,…

Recent work has investigated the origin of infant colour categories, showing pre-linguistic infants categorise colour even in the absence of colour words. These infant categories are similar but not identical to adult categories, giving rise to an important question about how infant colour perception changes with the learning of colour words. Here…

Previous research suggests that exposure to accent variability can affect toddlers' familiar word recognition and word comprehension. The current preregistered study addressed the gap in knowledge on early language development in infants exposed to two dialects from birth and assessed the role of dialect similarity in infants' word recognition and…

Before they even talk, infants become sensitive to the speech sounds of their native language and recognize the auditory form of an increasing number of words. Traditionally, these early perceptual changes are attributed to an emerging knowledge of linguistic categories such as phonemes or words. However, there is growing skepticism surrounding…

Background: Variability in the vocabulary outcomes of children with cochlear implants (CIs) is partially explained by child-directed speech (CDS) characteristics. Yet, relatively little is known about whether and how mothers adapt their lexical and prosodic characteristics to the child's hearing status (before and after implantation, and compared…

Children comprehend iconic gestures relatively later than deictic gestures. Previous research with English-learning children indicated that they could comprehend iconic gestures at 26 months, a pattern whose extension to other languages is not yet known. The present study examined Turkish-learning children's iconic gesture comprehension and its…