There is substantial evidence that children's apparent omission of grammatical morphemes in utterances such as "She play tennis" and "Mummy eating" is in fact errors of commission in which contextually licensed unmarked forms encountered in the input are reproduced in a context-blind fashion. So how do children stop making such…

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…

Recent years have seen a flourishing of Natural Language Processing models that can mimic many aspects of human language fluency. These models harness a simple, decades-old idea: It is possible to learn a lot about word meanings just from exposure to language, because words similar in meaning are used in language in similar ways. The successes of…

Infants are immersed in a world of sounds from the moment their auditory system becomes functional, and experience with the auditory world shapes how their brain processes sounds in their environment. Across cultures, speech and music are two dominant auditory signals in infants' daily lives. Decades of research have repeatedly shown that both…

New motor skills supply infants with new possibilities for action and have consequences for development in unexpected places. For example, the transition from crawling to walking is accompanied by gains in other abilities--better ways to move, see the world, and engage in social interactions (e.g., Adolph & Tamis-LeMonda, 2014). Do the…

Neural network models have recently made striking progress in natural language processing, but they are typically trained on orders of magnitude more language input than children receive. What can these neural networks, which are primarily distributional learners, learn from a naturalistic subset of a single child's experience? We examine this…

It is known that the rhythms of speech are visible on the face, accurately mirroring changes in the vocal tract. These low-frequency visual temporal movements are tightly correlated with speech output, and both visual speech (e.g., mouth motion) and the acoustic speech amplitude envelope entrain neural oscillations. Low-frequency visual temporal…

Learning to walk allows infants to travel faster and farther and explore more of their environments. In turn, walking may have a cascading effect on infants' communication and subsequent responses from caregivers. We tested for an "inflection point"--a dramatic shift in the developmental progression--in infant communication and caregiver…

In order for children to understand and reason about the world in an adult-like fashion, they need to learn that conceptual categories are organized in a hierarchical fashion (e.g., a dog is also an animal). While children learn from their first-hand observation of the world, social knowledge transmission via language can also play an important…

Specific features of adult linguistic input may play a larger, or smaller role, at different child ages, across different language outcomes, in different cohorts. This prospective, longitudinal study explored associations between the quantity and quality (i.e. diversity and responsiveness) of maternal linguistic input and child language. This…

This paper revisits the longstanding observation that children produce modal verbs (e.g., must, could) with their root meanings (e.g., abilities, obligations) by age 2, typically a year or more earlier than with their epistemic meanings (e.g., inferences). Established explanations for this "Epistemic Gap" argue that epistemic language…

Parent language input is a well-established predictor of child language development. Multisensory attention skills (MASks; intersensory matching, shifting and sustaining attention to audiovisual speech) are also known to be foundations for language development. However, due to a lack of appropriate measures, individual differences in these skills…

Purpose: Understanding variability sources in early language interaction is critical to identifying children whose development is at risk and designing interventions. Variability across socioeconomic status (SES) groups has been extensively explored. However, SES is a limited individual clinical indicator. For example, it is not generally directly…

This longitudinal study examined the development of narrative micro- and macrostructure in Japanese-English bilingual returnee children. Returnees are children of immigrant families who move to a foreign country, spending a significant portion of their formative developmental years in the foreign majority language context before returning to their…

Narrative production draws upon linguistic, cognitive and pragmatic skills, and is subject to substantial individual differences. This study aimed to characterise the development of narrative production in late childhood and to assess whether children's cumulative experience of reading fiction is associated with individual differences in narrative…