How Words and Sounds Influence Category Formation in Infancy

这项研究将阐明词汇在生命最初几个月对分类的影响，并追踪这种影响在生命第一年的发展轨迹。这些研究的起点是研究人员最近的一项证明，即单词促进了3个月大的婴儿对物体的分类，而这种方式是仔细匹配的语调所不能做到的。这一结果为研究开辟了几条新的途径，每一条途径都将涉及生命第一年语言与概念组织之间的关系的基本问题。该项目将确定在这么小的婴儿中，除了语调序列的影响之外，语音刺激还能促进物体分类的原因是什么。拟议中的实验测试了一种假设，即人类的语言在非常小的婴儿身上产生了对周围物体的高度关注，并且随着婴儿对自己周围语言的语言声音的调谐，这种非常普遍的注意力效应后来变得更加具体。要实现这一假设，需要检查3到12个月大的婴儿对各种听觉刺激的处理情况。为了发现词汇对分类的促进作用是语言刺激所特有的，还是对其他复杂刺激也明显的，本实验采用了优先看任务。在这项任务中，研究人员向婴儿展示了一系列单独的图片，然后进行了测试，将一张新奇的图片和一张熟悉的图片并排呈现给婴儿，研究人员测量了婴儿看每一张图片的时间。该项目调查听觉刺激的影响，包括来自一系列语言的自然语言、过滤后的语言、反向语言、哺乳动物的发声和鸟类的叫声。这个项目的另一个重点是调查在双语家庭中成长的婴儿的发展轨迹。该项目侧重于典型发育的婴儿，将对单语和双语婴儿的规范发展理论产生广泛影响，并将对非典型发育的婴幼儿的干预产生影响。这项研究聚焦于人类两种独特的能力--语言和概念发展--并探索了它们之间正在出现的联系。通过规划这一环节的发展，拟议的研究将使从业者更好地识别偏离典型发展的模式。此外，通过考虑婴儿在双语环境中的成长，这项工作将解决有关在生命的第一年处理两种语言的后果的关键问题，并将推动努力促进美国越来越多的双语婴儿和幼儿取得积极的发展成果。最后，这项基础研究也可以作为跳板，为被诊断为语言延迟和障碍的幼儿以及那些被诊断为自闭症谱系障碍的儿童制定有针对性的干预措施。

The research will clarify the effect of words on categorization in the first months of life and trace the developmental trajectory of this effect over the first year of life. The starting point for these studies is a recent demonstration by the investigators that words promoted object categorization in infants as young as 3 months, and do so in a way that carefully matched tones do not. This result opens several new avenues for investigation, each of which will bear on fundamental questions concerning the relation between language and conceptual organization in the first year of life. The project will identify what it is about speech stimuli that promote object categorization over and above the effect of tone sequences in infants so young. The proposed experiments test the hypothesis that human speech engenders in very young infants a heightened attention to the surrounding objects, and that this very general attentional effect later becomes more specific as infants become attuned to the speech sounds of their own ambient language. Pursuing this hypothesis requires an examination of 3- to 12-month-old infants' treatment of a broad range of auditory stimuli. To discover whether the facilitative effect of words on categorization is specific to linguistic stimuli or evident for other complex stimuli as well, the proposed experiments use a preferential-looking task. In this task, the infant is presented with a series of individual pictures followed by a test trial in which the infant is presented with a novel and a familiar picture side-by-side, and the investigators measure how much time the infant spends looking at each picture. The project investigates the effects of auditory stimuli including naturalistic speech from a range of languages, filtered speech, backwards speech, mammal vocalizations, and bird calls. Another focus of this project is to investigate the developmental trajectory for infants growing up in bilingual homes. The project, focused on typically-developing infants, will have broad impact on theories of normative development in monolingual and bilingual infants and will have implications for interventions with atypically-developing infants and young children. The research focuses on two uniquely human capacities -- language and conceptual development -- and explores an emerging link between them. By mapping out the development of this link, the proposed studies will put practitioners in a better position to identify patterns that deviate from typical development. Moreover, by considering infants growing up bilingual, this work will address crucial questions about consequences of processing two languages in the first years of life, and will advance efforts to promote positive developmental outcomes for the ever-increasing number of bilingual infants and young children in the United States. Finally, this basic research can also serve as a springboard for developing targeted interventions for young children diagnosed with language delay and impairments, as well as those diagnosed with autistic spectrum disorders.