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…

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…

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…

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…

Research suggests that girls acquire language faster than boys, with gender differences most pronounced in vocabulary acquisition during early childhood. This study examines the role of gender in the acquisition of vocabulary and morphosyntax in Palestinian Arabic-speaking children aged 18 to 36 months. Using the Palestinian Arabic Communicative…

The account that word learning starts in earnest during the second year of life, when infants have mastered the disambiguation skills, has recently been challenged by evidence that infants during the first year already know many common words. The preliminary ability to rapidly map and disambiguate linguistic labels was tested in Italian-speaking…

Exposure to communicative gestures, through their parents' use of gestures, is associated with infants' language development. However, the mechanisms supporting this link are not fully understood. In adults, sensorimotor brain activity occurs while processing communicative stimuli, including both spoken language and gestures. Using…

Most deaf children have hearing parents who do not know a sign language at birth and are at risk of limited language input during early childhood. Studying these children as they learn a sign language has revealed that timing of first-language exposure critically shapes language outcomes. But the input deaf children receive in their first language…

Research on "parentese," the acoustically exaggerated, slower, and higher-pitched speech directed toward infants, has mostly focused on maternal contributions, although it has long been known that fathers also produce parentese. Given recent societal changes in family dynamics, it is necessary to revise these mother-centered models of…

Children's ability to recognize object shape is foundational for successful early word learning. However, the prototypical shape of objects may not be easily accessible--take margarita glasses, for instance. The current study examined 304 U.S. children 17- to 42-month-old (152 females) from 2017 to 2020, asking how shape, age, and vocabulary…

Vocabulary size is a crucial early indicator of language development, for both monolingual and bilingual children. Assessing vocabulary in bilingual children is complex because they learn words in two languages, and there remains significant controversy about how to best measure their vocabulary size, especially in relation to monolinguals. This…

By 12 months, English-learning infants have an awareness of the sound patterns of word forms that constitute acceptable labels for objects in their native language. In the following experiments, we replicated and extended previous findings that Canadian English-learning infants will not link function-like words with novel objects. Across three…