Brain Organization Underlying Language Processing: The Effect of Environmental

尽管孩子们学习语言看起来很容易，但在学习语言方面存在显著的个体差异 特定元素的发展过程，包括词汇和句法知识，手势的使用，以及 阅读的习得。儿童之间的一个重要区别是他们所处的语言环境 暴露，这对语言增长的速度和时间有重大影响。 在我们正在进行的纵向语言研究(LLS)中，我们已经表明，学龄前儿童的技能水平是 受学龄前投入的影响。下一步是确定早期输入和技能与后期的关系 与他们的成就和神经机制有关。在口语和阅读中，我们都注重单词 在听觉和正字法两个层面上的解码和句子理解。我们研究这一点 发育生物学在典型发育儿童和早期单侧脑损伤的儿童中都有。 我们围绕成人的几个可能的加工途径组织我们的生物学研究。 大脑，在童年的过程中发展，并受到儿童环境和环境的影响 经验。该模型将口语和阅读分为两个不同的部分，即单词译码 和句子理解能力。在口语通道中，单词解码涉及两个流，一个主要是 左侧化的“背流”，将声音映射到发音表示和双侧 代表将声音映射到词汇意义的“腹侧流”。在书面情态中，单个单词 解码似乎还涉及两条路径，都是相对偏左的，包括一条 通过分解(字素-音素转换)机制和“腹侧路径”对单词进行解码 它使用直接的视觉(词汇/语义)识别。句子理解的机制出现了 相对独立的形式，由前额叶和额叶下部的“前流”调节， 它将单词映射成句子级的句法和语义表示。 这些解码和理解系统的开发需要输入。我们假设 语音发展是听觉和书面语解码所必需的，它涉及到 顶端和前置马达电路，用于观察和模拟执行。书面语的发展 解码似乎需要这种语音系统和特殊的视觉过程之间的相互作用。 最后，理解系统的发展似乎依赖于照顾者言语的复杂性，并且 早期出现复杂的言语和手势。 总而言之，我们的目标是了解与口头和书面有关的神经活动模式 学龄儿童的语言理解，以及早期学龄前语言的作用 和手势来确定这个神经网络结构的结构。

Despite the apparent ease with which children learn language, there are striking individual differences in time course of growth of particular elements, including lexical and syntactic knowledge, use of gesture, and acquisition of reading. An important difference among children is the linguistic environment to which they are exposed, and this has a significant effect on the rate and timing of language growth. In our ongoing Longitudinal Language Study (LLS), we have shown that preschool skill levels are affected by preschool input. The next step is to determine the relationship of early input and skill to later achievement and to their neural mechanisms. In both oral language and reading, we focus on word decoding and sentence comprehension at both the auditory and orthographic levels. We study this developmental biology both in typically developing children and those with early unilateral brain lesions. We organize our biological investigations around several putative processing pathways in the adult brain, which develop over the course of childhood, and which are affected by the child's environment and experience. This model divides both oral language and reading into two distinct components, word decoding and sentence comprehension. In the oral modality, word decoding involves two streams, a predominantly left lateralized "dorsal stream" that maps sound onto articulatory representations and a bilaterally represented "ventral stream" that maps sound onto lexical meaning. In the written modality, single word decoding also seems to involve two pathways, both relatively left lateralized, including a "dorsal route" that decodes words by a decompositional (grapheme-phoneme conversion) mechanism and a "ventral route" that uses direct visual (lexical/semantic) recognition. The mechanisms for sentence comprehension appear to be relatively modality independent, mediated by an anterior temporal and inferior frontal "anterior stream", which maps words into sentence-level syntactic and semantic representations. Development of these decoding and comprehension systems requires input. We hypothesize that phonological development, required for both auditory and written word decoding, involves development of parietal and premotor circuits for observation and execution through imitation. Development of written word decoding appears to require interaction between this phonological system and specialized visual processes. Finally, development of comprehension systems appears to rely on the complexity of caregiver speech, and the early presence of complex speech and gesture. In summary, we aim to understand the patterns of neural activity associated with oral and written language comprehension in school-age children, and to characterize the role of early preschool language and gesture in determining the structure of this neural network architecture.