NEUROBEHAVIORAL DEVELOPMENT--NORMAL, LI & DEAF CHILDREN

描述（改编自研究者摘要）：提案的 广泛的目标是表征分化的时间过程， 神经系统在语言和感觉处理中起重要作用， 3个月至8岁的发育中儿童。拟议的研究将 测试以下假设--系统显示出最大程度的 发育可塑性在更长的时间内分化， 那些不太容易改变的对语言风险儿童的研究 语言障碍（晚说话者，LT）和被诊断为语言障碍的儿童 将观察到损害（LI）。来验证一个假设 在多个系统中可以导致LI，可以预测LI，并且 通过干预计划改变。先天性耳聋儿童研究 获得ASL探索特定类型的感觉输入的作用 假设是中央的语言系统的发展， 麸皮将在几个脑区域记录ERP，如正常、LI、 而聋儿处理刺激的目的是激活 感官和语言功能。将检验六个特定假设： (1)到30个月时，不同的神经系统介导词汇与 语法处理;这些系统显示出越来越多的分化 直到8年。(2)儿童会表现出语音的ERP证据 在6个月时启动，但相关的神经系统将继续 在整个童年中期发展。(3)加工过程中的重要系统 快速呈现的非语言听觉刺激区分沿着 早于语言相关的神经系统的时间过程，和背 视觉通路比腹侧通路在沿着更长的时间过程中分化 视觉流(4)最早反应的时间和组织 语言和非语言刺激预测LT儿童将赶上 然后变成了李。(5)在某些个体中，LI来自于 在感觉处理方面的缺陷，而在其他方面， 语言学(6)语言系统在生物学上的不变作用 左半球对口语和手语也遵循类似的时间进程 语言

DESCRIPTION (adapted from the investigator's abstract): The proposal's broad goals are to characterize the time-course of differentiation of neural systems important in language and sensory processing in normally developing children ages 3 months to 8 years. The proposed research will test the following hypothesis--systems that display the greatest degree of developmental plasticity differentiate over longer time periods than do those that are less modifiable. Studies of children at risk for language impairment (Late Talkers, LTs) and children with a diagnosis of language impairment (LI) will be observed. to test the hypothesis that alterations in multiple systems can lead to LI, can be predictive of LI, and are altered by intervention programs. Studies of congenitally deaf children acquiring ASL explore the role of specific types of sensory input hypothesized to be central to the development of the language systems of the bran. ERPs will be recorded over several brain regions as normal, LI, and deaf children process stimuli designed to activate specific aspects of sensory and language functions. Six specific hypothesis will be tested: (1) By 30 months, distinct neural systems mediate lexical versus grammatical processing; these systems display increasing differentiation until 8 years. (2) Children will show ERP evidences of phonological priming at 6 months, but the associated neural systems will continue to develop throughout middle childhood. (3) Systems important in processing rapidly presented non-language auditory stimuli differentiate along an earlier time-course than language-relevant neural systems, and the dorsal visual pathway differentiates along a longer time-course than the ventral visual stream. (4) The timing and organization of the earliest responses to speech and non-speech stimuli predict which LT children will catch up and which will go on to become LI. (5) In some individuals, LI arises from deficits in sensory processing while in others the deficit is specifically linguistic. (6) The biologically invariant role of language systems in the left hemisphere follows a similar time-course for both spoken and signed languages.