Development of Phonotactic Knowledge in Infancy

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Though much research has sought to better understand the process of language acquisition, many fundamental questions regarding how infants complete the enormous task of learning a language within just a few years remain without a definitive answer. So far, researchers have compiled a basic timeline for the acquisition of linguistic knowledge, and proposed two learning mechanisms: a bias leading infants to pay more attention to speech sounds that are easier to produce, and general statistical induction skills that are used to process various kinds of sensory input. Which mechanism is operative remains a continuing and fundamental debate from both theoretical and experimental perspectives. Surprising results from a recent pilot study indicate that infants make use of certain information regarding sound sequencing as early as 4.5 months, 4 months earlier than the previously established age. The revised findings appear to be the result of using experiments that present words to infants in phonetically controlled comparisons, rather than as a random selection. The dissertation seeks not only to confirm the pilot findings, but also to uncover further evidence regarding which of the two proposed learning mechanisms primarily facilitates acquisition of this early knowledge. The research will employ the well-established Head-turn Preference paradigm, in which words are played to an infant on a speaker, accompanied by a blinking light. The infant's attention to the words is indicated by turning toward the light. The experiment monitors the amount of time that infants attend to different kinds of stimuli, demonstrating the distinctions that are evident to them at that particular age. The innovation in this study lies in the stimuli the infants hear: the forms presented contrast specific sound patterns, in particular the distinction of voicing between fricative sounds (such as f, s, and sh versus v, z, and zh). This new approach allows for further exploration of fundamental questions regarding how infants learn language, a crucial aspect of human interaction.