Word Learning and Word Knowledge in Monolingual and Sequential Bilingual Children

描述（由申请人提供）：在美国，有近4700万人说英语以外的语言。然而，双语儿童的典型和非典型语言发展模式尚不清楚，因此构建有效可靠的双语评估工具的能力有限。由于语言障碍的早期诊断有助于成功干预，并最终影响儿童的生活质量，因此缺乏适合双语儿童使用的评估工具构成了重大的健康风险。本研究的长期目标是开发适合不同熟练程度的双语儿童使用的基于理论的评估方法。本研究的目的是利用工作记忆的理论框架来考察顺序双语儿童词汇学习任务是否以及如何索引词汇知识。实验1将比较5-6岁的西班牙-英语顺序双语儿童和单语儿童学习语音熟悉的、遵循英语语音结构的新单词的能力。假设英语词汇知识会影响儿童在语音熟悉的单词学习任务中的表现。由于顺序双语者在英语（他们的第二语言）中的词汇量比母语为英语的人要弱，因此预测单语儿童在语音熟悉的任务中会比顺序双语儿童表现得更好。实验2将比较西班牙-英语顺序双语和单语儿童学习语音不熟悉的新单词的能力，这些单词既不遵循英语也不遵循西班牙语的语音结构。假设英语词汇知识对语音不熟悉的新单词的编码影响有限。因此，我们预测顺序双语者和单语者在语音不熟悉任务上的表现水平相当。本文还将探讨双语儿童与单语儿童的词汇技能与词汇学习表现之间的关系。如果发现单词学习任务索引的是双语儿童的概念性词汇知识，而不是特定于英语的词汇知识，那么就可以支持对双语儿童进行单词学习任务的诊断性使用。如果语音不熟悉的任务在双语儿童和单语儿童中产生相当的表现水平，那么它的使用可以推广到其他具有不同语言学习历史和熟练程度概况的双语儿童。从理论上讲，本实验将检验单语儿童与双语儿童相比，工作记忆模型适应和预测词汇知识与语音记忆能力之间关系的能力。

DESCRIPTION (provided by applicant): Nearly 47 million individuals speak languages other than English in the United States. However, patterns of typical and atypical language development in bilingual children remain unclear, and the ability to construct valid and reliable bilingual assessment tools is therefore limited. Since early diagnosis of a speech-language impairment is instrumental to successful intervention, and ultimately, to the child's quality of life, the lack of assessment tools appropriate for use with bilingual children constitutes a significant health risk. The long-term goal of this research is to develop theoretically-grounded assessment methods appropriate for use with bilingual children along a wide range of proficiency levels. The goal of the present work is to use the theoretical framework of working memory to examine whether and how word-learning tasks index vocabulary knowledge in sequential bilingual children. Experiment 1 will compare Spanish-English sequential-bilingual and monolingual children ages 5-6 on their ability to learn phonologically-familiar novel words that follow the English phonological structure. It is hypothesized that knowledge of English vocabulary will influence children's performance on the phonologically-familiar word-learning task. Because sequential bilinguals have weaker vocabulary in English (their second language) compared to native speakers of English, it is predicted that monolingual children will outperform sequential-bilingual children on the phonologically-familiar task. Experiment 2 will compare Spanish-English sequential-bilingual and monolingual children on their ability to learn phonologically-unfamiliar novel words that do not follow either the English or the Spanish phonological structure. Knowledge of English vocabulary is hypothesized to have limited effect on encoding of phonologically-unfamiliar novel words. Therefore, it is predicted that sequential bilinguals and monolinguals will demonstrate comparable performance levels on the phonologically-unfamiliar task. The relationship between vocabulary skills and word-learning performance in bilingual vs. monolingual children will also be examined. If word-learning tasks are found to index bilingual children's conceptual rather than English-specific vocabulary knowledge, diagnostic use of word-learning tasks with bilingual children can be supported. If the phonologically-unfamiliar task yields comparable performance levels in bilingual and monolingual children, its use can be generalized to other bilingual children with different language-learning histories and proficiency profiles. Theoretically, the experiments will test the ability of the working memory model to accommodate and predict the association between vocabulary knowledge and phonological memory capacity in monolingual compared to bilingual children. PUBLIC HEALTH RELEVANCE: The current project aims to improve diagnostic practices with children who speak English as a second language, and who therefore cannot be tested using tools developed for monolingual English-speaking children. In the proposed work, we test whether word-learning tasks can serve as markers of typical vocabulary development in Spanish-speaking bilingual children who are acquiring English as a second language. Because early diagnosis of a language difficulty is key to successful intervention and to the child's ultimate quality of life, identification of tasks that can accurately index bilingual children's typical vs. atypical development can make significant contribution to public health.