Toddlers better retain novel object-label mappings from taxonomic categories they have more knowledge of. Separately, words for concepts with more perceptual features are learned earlier than words for concepts with fewer perceptual features. Because these factors have only been examined separately, it is unclear whether the effects of taxonomic…

The cognitive mechanisms and benefits of active learning in early child development are poorly understood. The current study investigated 20-23-month-old infants' curiosity-driven information selection in a novel word learning task, designed to identify any potential advantage for active learning over passive learning. In a gaze-contingent…

Emotion and language are very common in young children's everyday lives. Hour by hour, they play, listen, vocalize, react, and emote. Despite the centrality of emotion and language to toddlers' local environments, the dynamic interplay of these communicative signals is practically unexplored. Here, we investigated how fluctuations in caregiver and…

Very large numbers words such as "hundred," "thousand," "million," "billion," and "trillion" pose a learning problem for children because they are sparse in everyday speech and children's experience with extremely large quantities is scarce. In this study, we examine when children acquire the…

Relatively little work has focused on why we are motivated to learn words. In adults, recent experiments have shown that intrinsic reward signals accompany successful word learning from context. In addition, the experience of reward facilitated long-term memory for words. In adolescence, developmental changes are seen in reward and motivation…

Early vocabulary development benefits from diverse lexical exposures within children's language environment. However, the influence of lexical diversity on children as they enter middle childhood and are exposed to multimodal language inputs remains unclear. This study evaluates global and local aspects of lexical diversity in three…

The last decade has seen an exponential rise in children's digital media use, as well as growing evidence that it is associated with changes in children's vocabulary. However, while high rates of low-quality digital media have been associated with lower "amounts" of words a child says, little work has examined whether digital media…

Infants experience language in rich multisensory environments. For example, they may first be exposed to the word applesauce while touching, tasting, smelling, and seeing applesauce. In three experiments using different methods we asked whether the number of distinct senses linked with the semantic features of objects would impact word recognition…

Questions about early word knowledge pervade the literature on both typical and atypical language trajectories. To determine which words an infant knows, researchers have relied on two types of measures--caregiver-report and eye-gaze behavior. When these measures are compared, however, their results frequently fail to converge, making it difficult…

As adults, we represent and think about number, space, and time in at least two ways: our intuitive--but imprecise--perceptual representations, and the slowly learned--but precise--number words. With development, these representational formats interface, allowing us to use precise number words to estimate imprecise perceptual experiences. We test…

Although identifying the referents of single words is often cited as a key challenge for getting word learning off the ground, it overlooks the fact that young learners consistently encounter words in the context of other words. How does this company help or hinder word learning? Prior investigations into early word learning from children's…

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…

This study investigates how neural networks address the properties of children's linguistic knowledge, with a focus on the "Agent-First" strategy in comprehension of an active transitive construction in Korean. We develop various neural-network models and measure their classification performance on the test stimuli used in a behavioural…

We introduce a novel method to test a classic idea in developmental science that children's attention to a stimulus is driven by how much they can learn from it. Preschoolers (4-6 years, M=4.6) watched a video where a distracting animation accompanied static, page-by-page illustrations of a storybook. The audio narration for each storybook page…

Previous studies showed that word learning is affected by children's existing knowledge. For instance, knowledge of semantic category aids word learning, whereas a dense phonological neighbourhood impedes learning of similar-sounding words. Here, we examined to what extent children associate similar-sounding words (e.g., rat and cat) with objects…