DEVELOPMENT OF CEREBRAL SPECIALIZATIONS

本应用程序的长期目标是评估 感官和语言经验在功能发展中的作用 专门的神经系统 功能的不同概念 视觉系统和语言系统的组织将是 在正常成年人的研究中进行了测试， 这些系统的开发将通过研究来确定 具有特定改变的个体群体， 感觉和/或语言体验的时间安排。 事件相关脑 将从多个大脑区域记录电位（ERP）， 单语和双语听力受试者， 英语发生在不同的年龄段，先天性耳聋和听力下降 第一次接触ASL发生在不同年龄的个体， 执行旨在激活感官和感官的特定方面的任务， 语言功能。 六个系列拟议实验的具体目标 是：I.为了验证这个假设， 视觉系统内的流受到以下因素的不同影响： 先天性听觉缺失 二.为了评估假设， 语法信息和面部表情之间的时间重合 ASL中的表达导致左半球更大的 聋人和听力正常的土著人的面部表情。 三. 探讨 假设语义和语法信息的加工 在英语中是由不同的神经系统介导的， 关键时期，并进一步区分规则和约束 在语法子系统中。 四.为了探索这个假设， (a)在调节ASL的神经系统中存在重叠， （B）可以在每个子系统中识别出相似的子系统， 独立于模态和（c）模态约束产生 调节语法处理的神经系统的差异 英语和ASL V.为了探索类似神经元 具有相似关键期的系统介导了 英语和美国手语中的语音信息。 六.利用掩蔽 对比语言的自动处理和控制处理的范例 和非语言材料，并测试假设，自动 功能更容易受到改变的早期经验比 控制加工过程。 从长远来看，这些研究应该提供以下信息： 对开发、提炼和评估具有现实意义 聋人和语言障碍者的康复和教育方案 个体 由于这些研究将评估 当改变的经验产生最大的影响时， 研究结果还将对特定的教育 这些计划将优化听力正常儿童的发育。

The long-term objectives of this application are to assess the roles of sensory and language experience in the development of functionally specialized neural systems. Different conceptions of the functional organization of the visual system and the language system will be tested in studies of normal adults and the effects of altered input on the development of these systems will be determined through the study of groups of individuals with specific alterations in the nature and timing of sensory and/or language experience. Event-related brain potentials (ERPs) will be recorded from over several brain regions as monolingual and bilingual hearing subjects whose first exposure to English occurred at different ages, and congenitally deaf and hearing individuals whose first exposure to ASL occurred at different ages, perform tasks designed to activate specific aspects of sensory and language functions. The specific aims of each of the six series of proposed experiments are: I. To test the hypothesis that the dorsal and ventral processing streams within the visual system are differentially affected by auditory deprivation since birth. II. To assess the hypothesis that the temporal coincidence between grammatical information and facial expression in ASL results in greater left hemisphere representation of faces in deaf and hearing native signers. III. To explore the hypothesis that the processing of semantic and grammatical information in English is mediated by different neural systems with different critical periods and to further differentiate rules and constraints within the grammatical subsystem. IV. To explore the hypothesis that (a) there is overlap in the neural systems that mediate ASL and English, (b) similar subsystems can be identified within each that are independent of modality and (c) modality constraints produce differences in the neural systems that mediate grammatical processing in English and ASL. V. To explore the hypothesis that similar neural systems with similar critical periods mediate the processing of phonological information in English and ASL. VI. To utilize masking paradigms to contrast automatic and controlled processing of language and non-language material and to test the hypothesis that automatic functions are more vulnerable to altered early experience than are controlled aspects of processing. In the long run these studies should contribute information of practical significance for developing, refining and evaluating rehabilitative and educational programs for deaf and language impaired individuals. Since these studies will evaluate the periods in development when altered experience has its greatest impact, the results will also have implications for when specific educational programs would optimize development in normal hearing children.