Early word learning in English- and Mandarin-acquiring infants

Northwestern University, Evanston IL

Investigators

Abstract

Humans are uniquely endowed with a natural capacity for building complex, flexible, and creative conceptual and linguistic systems. This project provides a window through which to view the link between these two uniquely human systems -- across development and across languages. An essential developmental task for human infants is to form concepts that capture the commonalities and relations among the objects and events they encounter, and to learn words to express them. Even before infants begin to speak, these developmental tasks are powerfully linked. Infants begin the task of word learning with a broad, universal expectation. This sets the stage for the emergence of more specific expectations, linking particular kinds of words (e.g., noun, verb) to particular kinds of meaning (e.g., object- and event-based commonalities). These more specific expectations emerge in a cascading fashion over the first two years, tuned by the structure of the infant's native language. Past research has underscored the vital interaction between infants' broad early expectations and the shaping role of their native language environment. The overarching goal of the current project is to concentrate on the two types of evidence -- developmental and cross-linguistic -- that will reveal how the links between words and concepts unfold. Focusing on the second year of life, the experiments trace the acquisition of two kinds of words -- nouns and verbs -- in infants acquiring either English or Mandarin. Evidence from Mandarin offers a clear linguistic counterpoint to English and will engage, for the first time, a long-standing debate concerning whether and how infants' lexical and conceptual development are shaped by the language being acquired. The results will provide a detailed analysis of infants' emerging capacities in concept and word learning. Recruiting state-of-the-art time-series analyses, the project will identify with precision how 18- and 24-month-old infants deploy their visual attention as they are engaged in the very process of mapping novel words to meaning. The project will also clarify not only whether infants at a particular age can successfully learn new word meanings, but will also shed light on the efficiency with which they do so. This research will lead to fundamental advancements in scientific knowledge. Focusing on English and Mandarin, it will identify, for the first time, the impact of these distinctly different ambient languages on infants' language and conceptual development. In addition, there is a strong training component aimed at bringing members of underrepresented groups into the research process. By illuminating developmental patterns and processes in two distinct languages, this project will provide a means to better understanding how infants acquiring languages other than English learn words and concepts. This will advance the nation's efforts to promote positive developmental outcomes for the ever-increasing number of infants and young children in the U.S. from non-English-speaking home environments. By identifying the kinds of visual and linguistic support required for successful word learning, this basic research may also serve as a springboard for developing targeted interventions for infants and young children diagnosed with language delay or impairments. Tailoring the amount and kind information to capitalize on these children's strengths may prove especially effective in treatment.