DEVELOPMENTAL SPEECH PERCEPTION AND BRAIN PLASTICITY

在过去的40年里，关于语言起源的争论在理论上呈现出两种对立的立场，一种观点认为语言在很大程度上是天生的，另一种观点认为语言是后天习得的。我们对语言发展的理解的最新进展使我们超越了语言要么是本能要么是学习的断言，并告诉我们一些关于婴儿习得一种特定语言的实际步骤。数据显示，生物倾向和通过接触语言获取信息的能力是密不可分的。比“互动主义者”的观点更重要的是研究结果本身的细节，揭示了婴儿如何从一个层次到另一个层次，如何使用我们没有预料到的策略，从接触语言中获取新信息。该实验室的数据表明，在发育的最初阶段，婴儿的感知以一种极大地帮助语言感知的方式构建，显示出支持语言的丰富的初始结构。此外，我们的跨语言研究表明，一旦经历发生，婴儿就会表现出非凡的能力来获得特定语言的独特属性。我们表明，接触一种特定的语言会以一种有趣的方式早期改变婴儿的感知。当婴儿“映射”他们母语的语音参数时，感知是动态重构的。这些新的数据促使库尔提出了一个新的理论，叫做母语磁铁理论。它已经开始影响语音和语言，以及更广泛的领域，包括儿童发展、神经科学、神经生物学和计算建模。该理论作为本文研究的背景框架。为了验证这一理论并进一步提高我们对婴儿语言发展的认识，我们提出了四条研究方向：(a)婴儿语言感知的发育变化，研究6至12个月间语言感知的转变；(b) 6-12个月大婴儿言语感知的脑相关（MMN）， (c)对婴儿语言输入的分析，详细检查婴儿定向言语的语音内容，以及(d)婴儿语音信息的可塑性，研究暴露于外语的影响，以评估婴儿对新语音信息的敏感性是否，何时以及如何随着年龄和语言经验而变化。这四条汇集的研究路线应该产生的数据不仅可以解决言语和语言发展的具体理论，还可以解决生物学和文化之间界面的更一般的理论。

During the last 40 years, debate on the origins of language has featured two theoretically dichotomous positions, one that language is largely innately specified, and another, that language is explicitly learned. Recent advances in our understanding of language development take us beyond assertions that language is either instinctual or learned, and teach us something about the actual steps involved in infants' acquisition of a particular language. The data show that biological predispositions and the ability to acquire information through exposure to language are inextricably intertwined. More important than the "interactionist" view this reflects are the details of the findings themselves, revealing how infants move from one level to another, acquiring novel information from exposure to language, using strategies we had not predicted. Data from this laboratory show that in the earliest periods of development, infant perception is structured in a way that greatly assists speech perception, demonstrating a rich initial structure that supports language. Moreover, our cross-language studies show that once experience occurs, infants display an extraordinary ability to acquire the unique properties of a specific language. We show that exposure to a particular language alters infant perception early and in an interesting way. Perception is dynamically restructured as infants "map" the phonetic parameters of their native language. These new data prompted Kuhl to articulate a new theory called the Native Language Magnet theory. It has begun to have an impact within speech and language, as well as in broader areas, including child development, neuroscience, neurobiology, and computational modeling. The theory acts as the background framework for the studies in this proposal. Four converging lines of research are proposed to test the theory and further advance our knowledge of infant speech development: (a) developmental change in infant speech perception, examining the transition in speech perception that occurs between 6 and 12 months; (b) brain correlates (MMN) of speech perception in 6-12 month old infants, (c) analysis of language input to infants, examining the phonetic content of infant-directed speech in detail, and (d) plasticity for phonetic information in infancy, studies that examine the impact of exposure to a foreign-language to assess whether, when, and how infants' sensitivity to new phonetic information changes with age and linguistic experience. The four converging lines of research should produce data that not only address specific theories of speech and language development, but more general theories of the interface between biology and culture.