Decoding continuous speech in infancy

这个项目的第一个目标是研究儿童如何开始从连续的言语中提取词形。第二个目标是考察儿童如何将提取的词形与预期的词义联系起来。这两项任务都远非微不足道。在语音中寻找单词是一个挑战，因为自然语音中不包含完全可靠的单词边界线索。成年人只将言语理解为一串不连续的单词，因为他们知道特定于语言的单词边界线索。将意义附加到单词形式也很困难，因为即使在公开的标签场景中，对象和其预期标签之间也很少有一对一的明确映射。想象一下，当一个孩子走在城市人行道上时，听到母亲热情地说出‘鸽子’这个词，你就明白了在言语中寻找词语并确定它们的本意是多么困难。孩子必须完成哪些任务才能将这个词添加到他们的词汇表中？首先，孩子必须确定发音是一个单词(鸽子)还是两个单词(Pih Gin)。假设孩子能理解“鸽子”是一个单词，那么她该如何确定这个单词的意思呢？它是指疾驰而过的汽车，街角的停车标志，她松动的鞋带，还是她妈妈指着的鸟的步态？许多当代的语言习得和言语感知模型将儿童在这些单词学习情景中的成功归因于儿童对环境中事件和对象之间的统计关系进行跟踪和计算的敏锐能力。例如，儿童可能能够确定‘pih’和‘gin’的发音是一个词而不是两个词，因为音节‘pih’和‘gin’总是同时出现。孩子还可能意识到这个词指的是一种特定的鸟，因为她注意到几乎每次说出这个词时，视野中都会出现一只灰色的鸟。在本项目中，我们探索了这些语言习得分布模式的生态有效性。通过揭示正常语言发展的机制，我们将使未来的研究人员更好地理解言语和语言发展的正常和异常模式。

The first aim of this project is to examine how children begin to extract word forms from continuous speech. The second aim is to examine how children link extracted word forms to intended word meanings. Both tasks are far from trivial. Finding words in speech is is a challenge because natural speech contains no fully reliable cues to word boundaries. Adults only perceive speech as a string of discrete words because they know language-specific cues to word boundaries. Attaching meaning to word forms is also difficult because even in overt labelling scenarios, there is rarely a one-to-one unambiguous mapping between an object and its intended label. To appreciate the difficulty of finding words in speech and determining their intended meaning, imagine a child who hears her mother enthusiastically utter the word 'pigeon' while walking along a city sidewalk. What tasks must be achieved before the child can add this word to their vocabulary? First, the child must determine whether the utterance contains one word ('pigeon') or two words ('pih gin)'. Assuming the child can work out that 'pigeon' is one word, how does she then determine what the word means? Does it refer to the cars whizzing past, the stop sign on the corner, her loose shoelace, or the gait of the avian creature her mom is pointing at? Many contemporary models of language acquisition and speech perception attribute children's success in these word learning situations to children's keen ability to track and compute statistical relationships between events and objects in their environment. For example, the child might be able to determine that the utterance 'pidgin' is one word rather than two because the syllables 'pih' and 'gin' consistently co-occur. The child might also realize that this one word refers to a particular type of bird because she notices that nearly every time the word is uttered, a grey bird is in sight. In the current project, we explore the ecological validity of these sorts of distributional models of language acquisition. By uncovering the mechanisms involved in normal language development, we will position future researchers to better understand both normal and abnormal patterns of speech and language development.