Effects of Recast Rate and Distribution on Irregular Past Tense Acquisition

描述（由申请人提供）：具有特定语言障碍（SLI）的儿童在其语法发展方面落后于具有典型语言发展（TL）的儿童，尽管在对话中早期暴露于一种称为重铸的成人语法纠正形式（Fey等人，1999），以及他们在干预中从重铸中学习的能力，与TL儿童一样快（纳尔逊等人，1996年）。重铸是成人对儿童话语的直接反应，重复儿童的一些单词并纠正或以其他方式修改儿童先前话语的形态或句法形式，同时保持儿童产生的中心意义。例如，如果一个孩子说“它掉下来了”，一个成年人纠正重铸将是“它掉下来了”。从一种理论观点来看，SLI儿童的语法问题的基础涉及工作记忆、处理速度和能力的限制（伦纳德等人，2007年）。伦纳德等人认为，减少处理需求并提供多次重复单词和句子的干预方法有可能超越处理限制。重铸的促进性质和在治疗中使用的灵活性使他们有能力满足这些条件。然而，问题仍然存在，临床医生如何在干预中最有效地使用重铸？Warren et al.（2007）认为，儿童语言领域是时候开始专门研究治疗强度的组成部分，如剂量及其对治疗效果的影响。目前，这种研究几乎不存在。拟定的研究将开始通过检查剂量的两个具体方面来填补这一空白：重铸率和重铸分布。本研究的具体目的是确定重铸率和分布影响收购的不规则过去时态的新动词，由24名儿童SLI（4-和5奥尔兹）和24名年轻的，语言等效的儿童TL（3奥尔兹）。本研究采用多因素组间设计，包括两个独立的实验任务。实验一考察了儿童在五个阶段中，以0.5/min、1.0/min和1.5/min三种重铸率中的一种重铸率学习两个不规则过去时的新动词（dake-doke和kig-kug）。实验二考察了儿童对两种不规则过去时小说动词（jare-jore和twink-twank）的习得情况。结果变量包括在会话期间和测试后的探测中，目标动词在强制性语境中的准确产出百分比。本研究计划是第四项研究，该研究有三个长期目标：（1）建立有效的早期干预技术，有助于改善SLI的长期人际和学业后果;（2）详细了解影响SLI儿童形态句法习得的语言加工限制;以及（3）发展一个动态的评估方案，区分晚说话的幼儿与SLI与TL。该研究的方法和结果将为未来的随机临床试验做出重要贡献。该项目将提供有关广泛使用的干预方法-句子改写-剂量的具体信息，这有助于具有典型语言发展的儿童的语法发展（参见第10段）。Farrar，1992年）和那些有特殊语言障碍的人（参见。纳尔逊，卡马拉塔，威尔士，布托夫斯基和卡马拉塔，1996年）。确定有效的重铸剂量参数可能被证明是对特定语言障碍儿童进行一致、有效干预的关键（Warren，Fey & Yoder，2007）。对于有特殊语言障碍的儿童，快速和早期提高语法技能，使其接近正常发育的同龄人的水平，将是非常有益的（Fey & Proctor-Williams，2000），因为他们表现出长期的人际关系（参见凯泽，蔡，汉考克，和福斯特，2002年），和学术困难（比照。Catts & Kamhi，1999年）的人口和相关的社会成本。

DESCRIPTION (provided by applicant): Children with specific language impairment (SLI) lag behind children with typical language development (TL) in their grammatical development, despite equivalent early exposures to a form of adult grammatical corrections in conversation, called recasts (Fey et al., 1999), and their demonstrated ability to learn from recasts in intervention as quickly as do children with TL (Nelson et al., 1996). Recasts are immediate adult responses to child utterances that repeat some of the child's words and correct or otherwise modify the morphologic or syntactic form of the child's prior utterance, while maintaining the central meaning of the child's production. For example, if a child said "It falled down", an adult corrective recast would be "It fell down". From one theoretical view, the basis of the grammatical problems of children with SLI involves limitations in working memory, and processing speed and capacity (Leonard et al., 2007). Leonard et al. suggest that intervention approaches that decrease processing demands and offer multiple repetitions of words and sentences have the potential to override processing limitations. The facilitative properties of recasts and the flexibility of their use in treatment give them the capability to fulfill these conditions. The question remains, however, how can clinicians employ recasts in intervention most efficaciously? Warren et al. (2007) suggest that it is time for the field of child language to begin specifically investigating components of treatment intensiveness, such as dosage, and their impact on treatment efficacy. Currently, such research is virtually nonexistent. The proposed study will begin to fill this gap through examination of two specific aspects of dosage: recast rate and recast distribution. The specific aim of this study is to determine how rate and distribution of recasts affects acquisition of irregular past tense of novel verbs, by 24 children with SLI (4- and 5-yr olds) and 24 younger, language equivalent children with TL (3-yr olds). This study, which utilizes a multifactor between groups design, includes two independent experimental tasks. Experiment 1 examines the children's learning of two irregular past tense novel verbs (dake-doke and kig-kug) in response to one of three rates of recasts, 0.5/min, 1.0/min, or 1.5/min, over five sessions. Experiment 2 examines the children's acquisition of two different irregular past tense novel verbs (jare-jore and twink-twank) when given 20 verb exposures each in 1, 2 or 5 sessions. Outcome variables include percent of accurate production in obligatory contexts of the target verbs during the sessions and on post-test probes. This research proposal represents the fourth study in a path of research that has three long- term goals: (1) establishment of efficacious early intervention techniques that will contribute to the amelioration of the long-term interpersonal and academic consequences of SLI; (2) a detailed understanding of language processing limitations that affect morphosyntactic acquisition of children with SLI; and (3) development of a dynamic assessment protocol that distinguishes late-talking toddlers with SLI from those with TL. The methodology and results of the proposed study will contribute significantly to future randomized clinical trials. PUBLIC HEALTH RELEVANCE This project will offer specific information about dosage for a widely-used intervention approach, sentence recasting, which facilitates the grammatical development of children with typical language development (cf. Farrar, 1992) and those with specific language impairment (cf. Nelson, Camarata, Welsh, Butovsky & Camarata, 1996). Identification of effective recast dosage parameters might prove to be the key to consistent, effective, intervention outcomes for children with specific language impairment (Warren, Fey & Yoder, 2007). In children with specific language impairment, rapid and early improvement in grammar skills to levels that approximate those of their typically developing peers would be of significant benefit, (Fey & Proctor-Williams, 2000) given the demonstrated long-term interpersonal (cf. Kaiser, Cai, Hancock, & Foster, 2002), and academic difficulties (cf. Catts & Kamhi, 1999) of this population and the associated costs to society.