Doctoral dissertation research: Infants' ability to discriminate statements and questions

University Of Southern California, Los Angeles CA

Investigators

Abstract

In English and many other languages, questions and statements differ structurally. For example, in English, questions often begin with wh-words (e.g. who, what, where, etc.) and auxiliary verbs switch positions with subjects (compare "I can see Jim" with "Can I see Jim?"). In addition, statements and questions differ in their prosody (the melody and rhythmic qualities of speech): Statements generally end with a final pitch drop and questions with a final pitch rise. As infants acquire a language, it is important for them to be able to differentiate statements and questions, otherwise they would not be able to learn the distinct grammatical rules and patterns associated with each type. Although many language acquisition theories assume that learners can differentiate these sentence types in the early stages of language acquisition, there is little evidence of when and how they do so. In a series of four experiments, this project explores when infants develop sensitivity to the differences between statements and questions, and the types of information they use to distinguish between them. The project tests the hypothesis that infants initially differentiate statements and questions using prosodic information, then learn to distinguish sentence types by attending to the initial words (e.g., "Can I ... ?" vs. "I can ... ."). This project will provide critical evidence about when and how infants begin to distinguish between statements and questions. The findings will have implications for speech processing in infants, as well as theories of grammatical acquisition. This project could add significant new knowledge to the types of distinctions pre-verbal infants can make about grammatically different sentence types, which could have broader impacts in theories of child language acquisition. By mapping out these abilities in typically developing children, these experiments could also translate to assessment and intervention of children at risk for language impairments.