Development of Speech Perception and Brain Plasticity

描述(申请人提供)：语言是人类的标志。在过去的50年里，关于语言的争论已经让位于对人类习得语言过程的新观点。理论变革的催化剂之一是对婴儿的实证研究。在过去的十年里，研究人员不仅绘制了婴儿何时获得有关母语特性的知识的图表，而且还绘制了他们如何获得知识的图表，这导致了语言学和心理学理论的修订。新的研究聚焦于语音单位，即构成单词的辅音和元音。该实验室的主要进展是跨语言数据显示，婴儿在发育的最早阶段通过接触语言进行学习，这改变了语言感知，以帮助语言学习。此外，我们的研究表明，早期的言语预示着后来的语言，母亲以婴儿为导向的言语的清晰度与婴儿的言语感知能力有关。最后，对婴儿和成年人听语言的大脑测量表明，在早期发育过程中，婴儿的大脑在神经上致力于母语语言的模式，这既促进了未来的语言学习，也促进了在一岁结束时发生的非母语言语感知的下降。这项关于早期言语感知的工作正在影响儿童的发展、神经科学、神经生物学和计算建模。作为该项目的一部分开发的早期言语测量正在用于包括自闭症在内的发育障碍的研究，并可能提供残疾的早期标记。这些数据促使母语磁铁模型的扩展，将神经承诺作为发育变化的机制。这一理论立场为本提案中的研究提供了背景和框架。为了检验这一理论并进一步加深我们对婴儿言语发展的认识，我们提出了四条共同的研究路线：(A)言语知觉发展及其对语言的影响；(B)早期言语和语言发展的大脑相关性；(C)语言输入对儿童的作用；以及(D)大脑可塑性和语言习得的“关键期”。这项研究将产生涉及言语和语言发展理论的数据，以及关于生物和文化之间的接口的更一般的理论。

DESCRIPTION (provided by applicant): Language is a hallmark of human beings. In the last 50 years, debates on language have given way to a new view of the process by which humans acquire language. One catalyst for theoretical change has been empirical studies on infants. In the last decade, researchers have not only charted when infants acquire knowledge about the properties of their native language, but how they do so, and this has caused a revision in linguistic and psychological theories. New research focuses on the phonetic units of speech, the consonants and vowels that form building blocks for words. Key advances from this laboratory are cross- language data showing that infants learn from exposure to language in the earliest periods of development and that this alters speech perception to assist language learning. Moreover, our studies show that early speech predicts later language, and that the clarity of mothers' infant-directed speech is linked to infants' speech perception abilities. Finally, brain measures on infants and adults listening to language suggest that, during early development, the infant brain "neurally commits" to the patterns of native language speech and that this both promotes future language learning as well as the decline in nonnative speech perception that occurs at the end of the first year of life. This work on early speech perception is impacting child development, neuroscience, neurobiology, and computational modeling. The early speech measures developed as a part of this project are being used in the study of developmental disabilities including autism, and may provide an early marker of the disability. The data prompted an extension of the Native Language Magnet model to incorporate neural commitment as the mechanism for developmental change. This theoretical position provides the background and 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) speech perception development and its impact on language; (b) the brain correlates of early speech and language development, (c) the role of language input to children, and (d) brain plasticity and the "critical period" for language acquisition. The research will produce data that address theories of speech and language development and more general theories of the interface between biology and culture.