Individual and joint contributions of the hemispheres to language comprehension

描述（由申请人提供）：正常的语言理解需要大脑许多部分的贡献和合作，从接收初始物理输入的感觉区域，通过与经常特征化的语言子过程相关的额叶和颞叶区域，到涉及换位思考和社会认知的大脑区域；因此，在日常语言和话语过程中，两个半球的大脑区域网络被招募。在过去的几十年里，右半球在正常语言理解中所起作用的证据已经积累起来，研究人员提出，每个半球都倾向于为理解所必需的不同语言功能服务。拟议的研究批判性地扩展了这项工作，检查了一些典型研究的语言过程由两个半球的不同贡献组成，而其他过程需要两个半球的输入才能参与。利用事件相关电位和一种称为事件相关光信号的新成像技术（它提供了时间和空间精度），这些研究将探索两个半球在正常、合理的句子的语义处理过程中随着时间的推移展开和相互作用时的单独和联合贡献。由于两个半球通过胼胝体进行交流，胼胝体大小的个体差异将与功能不对称联系起来，以更好地表征半球间的相互作用。公共卫生相关性：了解语言理解过程中两个半球如何合作具有广泛的意义，因为许多语言障碍与异常的侧脑模式或半球沟通缺陷有关。因此，对两个半球如何协同工作提供更全面的了解，有可能为获得性或先天性语言障碍的治疗方案或干预提供信息。

DESCRIPTION (provided by applicant): Normal language comprehension requires contributions and cooperation from many parts of the brain, ranging from sensory areas that receive the initial physical input, through frontal and temporal areas associated with oft-characterized language subprocesses, to brain areas involved in perspective-taking and social cognition; thus a network of brain areas, in both hemispheres, is recruited during everyday language and discourse processes. Evidence for a role of the right hemisphere in normal language comprehension has accumulated over the last several decades, and researchers have proposed that each hemisphere is disposed to serve different language functions necessary for comprehension. The proposed research critically extends this work, examining the idea that some typically-studied language processes are composed of distinct contributions from each hemisphere and that other processes require input from both hemispheres in order to be engaged. Using event-related potentials and a new imaging technique known as the event-related optical signal (which provides both temporal and spatial precision), these studies will explore individual and joint contributions of the two hemispheres as they unfold and interact over time during the semantic processing of normal, plausible sentences. Because the two hemispheres communicate through the corpus callosum, individual differences in callosal size will be linked to functional asymmetries to better characterize hemispheric interaction over time. PUBLIC HEALTH RELEVANCE: Understanding how the hemispheres cooperate during language comprehension has broad implications, as many language disorders have been associated with abnormal laterally patterns or deficient hemispheric communication. Providing a fuller picture of how the two hemispheres work together thus has the potential to inform treatment options or interventions for acquired or congenital language disorders.