The Development of Word Meaning

描述（由申请人提供）：单词学习是一个渐进的过程，由单词学习者的能力和单词学习环境提供的线索决定。我们的长期目标是阐明学龄儿童在现存词汇知识和词汇学习方面的个体差异。提出的设计利用了种群之间自然发生的变异。我们的方法包括在一组儿童中进行比较，将完整的社会和语言处理过程用于单词学习；在社会和语言处理成熟程度不同的幼儿和大龄儿童之间；在正常儿童和语言处理能力差的儿童（有特殊语言障碍的儿童）或社会推理能力差的儿童（自闭症儿童）之间。这些比较允许测试两个主要假设：1)单词学习的渐进或“缓慢映射”阶段取决于处理语言和社会线索的能力；2)在任何给定的时间点上，词汇中建立的语义知识的稳健性将影响单词使用的成功。具体目的是确定：

DESCRIPTION (provided by applicant): Word learning is a gradual process determined by the competencies of the word learner and cues provided by the word learning environment. Our long-term goal is to elucidate individual differences in both extant word knowledge and word learning among school-aged children. The proposed design takes advantage of naturally-occurring variation between populations. Our method involves comparisons within a group of children bringing intact social and linguistic processing to bear on word learning; between younger and older children with differing levels of maturity in social and linguistic processing; and between normal children and those with poor linguistic processing (children with specific language impairment) or poor social reasoning (children with autism). These comparisons allow tests of two main hypotheses: 1) the gradual or "slow-mapping" phase of word learning depends upon abilities to process a coalition of linguistic and social cues and 2) at any given point in time, the robustness of semantic knowledge established in the lexicon will affect the success of word usage. The specific aims are to determine: 1) how extant word knowledge varies with development, clinical status, and word class; 2) how receptive and expressive word usage vary with development, clinical status, and word class; 3) how the process and outcomes of slow mapping vary with development, clinical status, and word class; and 4) whether there is a causal relation between robustness of lexical semantic knowledge and speed or accuracy of word usage. This project will lead to discoveries about word learning during a rarely studied stage, slow mapping. It will also reveal sources of lexical deficits associated with SLI and autism, impairments affecting 7% and .3% of the U.S. population, respectively.