NEUROBEHAVIORAL DEVELOPMENT--NORMAL, LI & DEAF CHILDREN

描述（由申请人提供）：我们的主要目标是描述语言处理和相关注意和感觉技能中重要的神经系统和子系统的身份、发展时间过程和相对可塑性（可修改性/脆弱性）。在2-8岁的儿童中，我们将获得事件相关脑电位（ERPs），在6- 8岁的儿童中，我们还将获得大脑的结构和功能磁共振图像（MRI），以精确地描述受试者在执行旨在激活感觉和语言功能特定方面的任务时神经激活的时间和位置。在正常发育的儿童中，我们将根据我们之前的研究来验证这个假设，即发育时间较长的系统更脆弱，并且在有限的（和可变的）时间段内可以修改，而早期发育的系统则不那么脆弱，并且在整个生命中保持改变的能力。在年龄较小和较大的正常儿童群体中，我们将通过研究儿童的语言经验来评估这些系统的相对可修改性(1)在学年开始和结束时，教师在课堂上的演讲显示出更高或更低的句法复杂性和词汇多样性；(2)在旨在促进语言成长的干预计划的10周之前和之后。我们将测试这一假设，即增加语言输入会导致两个年龄组的语义和注意力技能以及相关神经系统的增加，但只会影响较年轻年龄组的语法和形态系统的发展。此外，我们将在年幼和年长的语言障碍（LI）儿童中对这些相同的系统进行表征，以评估关于导致LI的缺陷的不同假设，以及关于快速推进（FFW）、语法促进（GF）和基于叙述（NBLI）干预是否以及如何影响LI儿童的语言的相关假设。我们将评估FFW改善所有儿童的快速听觉加工和听觉注意技能的假设，GF和NBLI影响语法加工和相关神经系统，但仅在年幼的儿童中。由于所提出的研究将提供关于哪些感知和语言系统最受环境输入改变的证据，以及它们最易改变的时间段，这些研究将为教育和康复计划的发展、完善和评估提供具有实际意义的信息。

DESCRIPTION (provided by applicant): Our broad goals are to characterize the identity, developmental time courses and relative plasticity (modifiability/vulnerability) of neural systems and subsystems important in language processing and related attentional and sensory skills. In children 2-8 years of age we will acquire event-related brain potentials (ERPs) and, in 6- to 8-year-olds, we will also acquire structural and functional magnetic resonance images (MRI) of the brain to precisely characterize both the timing and the location of neural activations as subjects perform tasks designed to activate specific aspects of sensory and language functions. In normally developing children we will test the hypothesis, based on our previous research, that systems that have longer developmental time courses are more vulnerable and are modifiable during limited (and variable) time periods, whereas systems that develop early are less vulnerable and retain the ability to change throughout life. In younger and older groups of normal children, we will assess the relative modifiability of these systems by language experience by studying children (1) at the beginning and at the end of a school year in classrooms where teachers' speech displays either higher or lower syntactic complexity and lexical diversity and (2) before and after 10 weeks of an intervention program designed to facilitate language growth. We will test the hypothesis that increased language input leads to increases in semantic and attentional skills and related neural systems in both age groups, but will affect the development of grammatical and morphological systems only in the younger age group. In addition, we will characterize these same systems in younger and older language impaired (LI) children to assess different hypotheses about the deficits that give rise to LI, and related hypotheses concerning whether or not and how Fast ForWord (FFW), Grammatical Facilitation (GF) and Narrative-Based (NBLI) interventions impact language in LI children. We will assess the hypothesis that FFW improves rapid auditory processing and auditory attentional skills in all children and that GF and NBLI affect grammatical processing and related neural systems but only in younger children. Since the proposed research will provide evidence about which perceptual and language systems are most altered by environmental input, and the time periods when they are most modifiable, these studies wilt contribute information of practical significance for the development, refinement and evaluation of educational and habilitative programs.