Language Comprehension in Aging and AD

描述（由申请人提供）：无论语言是书面的还是口头的，随着时间的推移，对理解者的输入是可用的，输入的部分在时间上是不连续的，必须相互关联才能理解语言。因此，语言理解必须涉及一个临时存储或工作记忆系统。一些语言理解能力的下降被认为与工作记忆能力的下降有关。工作记忆能力随着年龄的增长而下降，而这种下降又与其他认知能力的下降有关，尤其是认知操作的速度。虽然WM、处理速度和语言理解在某种程度上肯定是相关的，但它们之间联系的确切性质还没有被完全理解。一个基本的问题是，语言处理、WM和处理速度的变化在多大程度上是统一的，在多大程度上是分离的。语言理解的某些方面被过度练习，可能不会受到其他口头任务中出现的WM限制或处理速度降低的影响。本研究拟通过对老年被试和AD患者的语言理解（在句子和话语层面）、WM和加工速度进行表征和关联，探讨语言理解、WM和加工速度之间的关系。这项研究将主要使用行为方法，但也将使用功能性神经影像学来提供关于这些关系的不同数据来源。

DESCRIPTION (provided by applicant): Regardless of whether language is written or spoken, the input to the comprehender becomes available over time and temporally discontinuous parts of the input must be related to one another for language to be understood. Thus, language comprehension must involve a temporary store or working memory system. Some decrements in language comprehension have been hypothesized to be related to decrements in working memory capacity. Working memory capacity declines with age and this decline has in turn been related to reductions in other cognitive capacities, in particular the speed with which cognitive operations can be carried out. While WM, processing speed and language comprehension are certainly related in some way, the exact nature of the connections between them is not fully understood. A basic question is the extent to which changes in language processing, WM and speed of processing are unitary vs. the extent to which they can dissociate. Some aspects of language comprehension are greatly over practiced and may not be affected by WM limitations or processing speed reductions that appear in other verbal tasks. The proposed research will investigate the relationship between language comprehension, WM and speed of processing by characterizing and relating language comprehension (at the levels of sentences and discourse), WM and processing speed in elderly participants and AD patients. The research will mainly use behavioral approaches, but will also employ functional neuroimaging to provide a different source of data regarding these relationships.