Brain Potentials (ERPS) Language, Memory, and Aging

描述（由申请人提供）：提出了一项为期五年的研究计划，其目的是澄清在语言理解中使用的语义记忆和语义分析的组织在多大程度上确实相对免于正常老化过程，正如人们普遍认为的那样。我们通过检查年龄对不同子过程的影响来评估这一信念;更具体地说，通过（1）比较和对比涉及相同概念（单词和图片）的不同感觉输入模式的处理;（2）研究语言中语义处理的两个不同贡献者-一个项目在其上下文中的语义整合以及随着上下文的产生而产生的各种语义约束挖掘语义记忆以理解传入的刺激（3）比较当一个半球有轻微的加工领先时，整个大脑对文字和图片加工的反应;（4）检查在敲击加工速度、抑制和工作记忆任务、强调感觉运动抑制的反眼跳任务、阅读广度任务和句子一致性阅读率任务中大脑/行为测量的个体差异。为此，我们分析了从18-90岁之间的（大脑）完整人类头皮记录的事件相关脑电位（ERP）以及他们处理文字或图片时的伴随行为。24个实验操纵刺激（视觉，图片）和上下文模态（口头的，图片的），刺激之间的关系的性质（分类，反义），遇到特定项目的概率（完形填空概率），是否以及，如果是的话，一个项目在它的上下文中的适合程度，一个项目的约束程度以及可预测性，以及在什么水平上（词汇的、语义的）、输入的视野和任务，或其组合。具体的目的是确定正常的衰老是否会改变两个半球对词汇、语义和上下文线索的敏感程度，以及两个半球如何使用它们来访问语义记忆和理解语言。通过这样做，我们测试了（1）我们的假设，即尽管每个人都从上下文中受益，但与年轻人不同，大多数老年人不会用它来预测即将到来的刺激的特征，尽管更高的语言熟练度可能会弥补这一点，（2）卡贝萨的假设，即老年人更有可能使用两个大脑半球来执行认知功能，而这些功能在年轻时主要由一个大脑半球负责，以及（3）众所周知的ERP效应与加工速度和认知功能的年龄相关变化之间的联系。该研究项目将完善在整个生命周期中语言处理和记忆使用中重要认知功能的ERP标记。这个规范的数据库将是有价值的所有年龄段的成人语义/语言处理障碍的评估。

DESCRIPTION (provided by applicant): A five year research program is proposed which is aimed at clarifying the extent to which the organization of semantic memory and semantic analyses, as used in language comprehension, are indeed relatively spared from the normal aging process, as is commonly believed. We assess this belief by examining effects of aging on different subprocesses; more specifically, by (1) comparing and contrasting processing of different modes of sensory input that refer to the same concepts--words and pictures; (2) examining two distinct contributors to semantic processing in language-the semantic integration of an item within its context and the various semantic constraints that accrue as context taps semantic memory to make sense of incoming stimuli prior to an item's appearance; (3) comparing the whole brain's response to word & picture processing when one hemisphere has a slight processing headstart; (4) examining individual differences in brain/behavioral measures in tasks tapping processing speed, inhibition, & working memory, an anti-saccade task accenting sensorimotor inhibition, a reading span task, and a sentence congruity reading rate task. To these ends we analyze event-related brain potentials (ERPs) recorded from the scalp of (brain) intact humans between 18-90 yrs of age and concomitant behavior as they process words or pictures. Twenty four experiments manipulate stimulus (visual, pictorial) and context modality (verbal, pictorial), the nature of relations among stimuli (categorical, antonymic), the probability that a particular item will be encountered (cloze probability), whether or not and, if so, how well an item fits within its context, how constrained and thus predictable an item is and at what level (lexical, semantic), visual field of input, and task, or combinations thereof. The specific aims are to determine whether or not and if so, how, normal aging changes what lexical, semantic, and contextual cues the two hemispheres are sensitive to and how each uses them to access semantic memory and to make sense of language. In so doing, we test (1) our hypothesis that though everyone benefits from context, most older adults, unlike younger ones, do not use it to predict features of upcoming stimuli, though greater verbal proficiency may compensate for this, (2) Cabeza's hypothesis that older adults are more likely to use both cerebral hemispheres to perform cognitive functions that were in their younger years the primary responsibility of just one, and (3) links between well-known ERP effects and age-related changes in processing speed and cognitive functions. This research project will refine ERP markers of important cognitive functions in language processing and memory use throughout the lifespan. This normative database will be of value for the assessment of adults of all ages with semantic/language processing disorders.