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…

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…

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…

Given the widespread interest in the development of children's selective social learning, there is mounting evidence suggesting that infants prefer to learn from competent informants (Poulin-Dubois & Brosseau-Liard, "Current Directions in Psychological Science," 2016, 25). However, little research has been dedicated to understanding…

There are two broad views of children's theory of mind. The mentalist view is that it emerges in infancy and is possibly innate. The minimalist view is that it emerges more gradually in childhood and is heavily dependent on learning. According to minimalism, children initially understand behaviors rather than mental states, and they are assisted…

Seminal work by Werker and colleagues (Stager & Werker [1997] "Nature," 388, 381-382) has found that 14-month-old infants do not show evidence for learning minimal pairs in the habituation-switch paradigm. However, when multiple speakers produce the minimal pair in acoustically variable ways, infants' performance improves in…

From the very first moments of their lives, infants selectively attend to the visible orofacial movements of their social partners and apply their exquisite speech perception skills to the service of lexical learning. Here we explore how early bilingual experience modulates children's ability to use visible speech as they form new lexical…

It is well attested that high socio-economic status (SES) is associated with larger vocabulary size estimates in young children. This has led to growing interest in identifying associations and mechanisms that may contribute to this relationship. In this study, parent-child reading behaviors were investigated in relation to vocabulary size in a…

Socioeconomic disparities in children's early vocabulary skills can be traced back to disparities in gesture use at age one and are due, in part, to the quantity and quality of communication children are exposed to by parents. Further, parents' mindsets about intelligence contribute to their interactions with their children. We implemented a…

The mutual exclusivity (ME) assumption is proposed to facilitate early word learning by guiding infants to map novel words to novel referents. This study assessed the emergence and use of ME to both disambiguate and retain the meanings of novel words across development in 18-month-old monolingual and bilingual children (Experiment 1; N = 58), and…

Vocabulary differences early in development are highly predictive of later language learning as well as achievement in school. Early word learning emerges in the context of tightly coupled social interactions between the early learner and a mature partner. In the present study, we develop and apply a novel paradigm--dual head-mounted eye…