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有两种立场，一种是语言在很大程度上是天生特定的，另一种是语言是显性的后天习得的。我们对语言发展理解的最新进展使我们超越了语言是本能的或后天习得的断言，并教会了我们一些关于婴儿习得特定语言的实际步骤。数据显示，生物的先天素质和通过接触语言获取信息的能力密不可分。比这反映出的“互动主义”观点更重要的是发现本身的细节，揭示了婴儿是如何从一个层面移动到另一个层面，使用我们没有预测到的策略，从接触语言的过程中获得新的信息。来自该实验室的数据显示，在发育的最早阶段，婴儿的感知结构极大地辅助了语言感知，展示了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，婴儿就会表现出获得特定语言独特属性的非凡能力。我们发现，接触一种特定的语言会在早期以一种有趣的方式改变婴儿的感知。感知是动态重组的，因为婴儿“映射”了他们母语的语音参数。这些新数据促使库尔提出了一种名为母语磁铁理论的新理论。它已经开始在言语和语言领域以及更广泛的领域产生影响，包括儿童发展、神经科学、神经生物学和计算建模。该理论为本提案中的研究提供了背景框架。为了检验这一理论并进一步提高我们对婴儿言语发展的认识，我们提出了四条趋同的研究路线：(A)婴儿言语知觉的发展变化，考察了6-12个月之间的言语知觉的转变；(B)大脑与6-12个月大婴儿的言语感知(MMN)相关；(C)对婴儿的语言输入进行分析，详细检查婴儿定向言语的语音内容；以及(D)婴儿期语音信息的可塑性，研究考察接触外语的影响，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的变化而变化。这四条交汇的研究路线应该产生的数据不仅涉及具体的言语和语言发展理论，而且还包括关于生物和文化之间接口的更一般的理论。

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.