Causal connections among infant motor actions and word learning

Infants hear thousands of words every day. How do they learn word meanings amidst the chaos and clutter of daily life? The context – where, when, and how words are spoken – is known to support infants’ word learning. Infants connect the words they hear to the accompanying context, including what they see, the location, and social cues from caregivers (e.g., the word “cup” is often spoken in kitchens, at mealtimes, with a cup in view). Such context cues help infants learn words. However, the role that infants’ own motor actions play in generating context cues remains unclear. Infants are not passive recipients of the language input they receive. Rather, infants’ motor actions often direct the conversation (e.g., an infant draws with crayons and their caregiver responds by saying, “are you drawing a picture?”). The goal of this project is to address two open questions: (1) Over the course of their development, are infants’ motor skill acquisitions related to the specific words they learn? (2) Does language input that aligns with infants’ motor actions facilitate word learning? The knowledge gained from this project stands to inform theories of language development that consider infants’ rapidly developing motor skills. Additionally, this project will provide in-depth research training opportunities to undergraduate and graduate students. Finally, this project seeks to generate a longitudinal, fully annotated video dataset of a diverse sample of infants and their caregivers, creating opportunities for data reuse and replication. Aim 1 of the project is to describe the naturalistic coordination between infants’ actions and caregivers’ language longitudinally across 2.5 years. Infants and their caregivers are video recorded at home for two hours during their typical daily routines over five sessions occurring at infants’ 6, 12, 18, 24, and 30 month anniversaries. The research team aims to identify caregivers’ spontaneous language input, infants’ motor actions, and infants’ vocabulary growth. Aim 2 of the project is to experimentally test whether action-language coordination facilitates in-the-moment word learning. The experimental setting involves measuring outcomes of novel word learning when infants hear the labels for novel objects synchronously with their actions or receive the same labelling input not synchronized to their actions. This project is jointly funded by the Developmental Sciences Program and the Established Program to Stimulate Competitive Research (EPSCoR). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.