Brain Potentials (ERPS) Language, Memory, and Aging

描述（由申请人提供）：提出一项为期五年的研究计划，旨在阐明用于语言理解的语义记忆和语义分析的组织在多大程度上确实不受正常老化过程的影响，正如人们普遍认为的那样。我们通过检查衰老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（文字和图片）的不同感官输入模式的加工；(2)研究了语言中语义加工的两个不同的因素——项目在其上下文中的语义整合，以及在项目出现之前，随着上下文利用语义记忆来理解传入刺激而产生的各种语义限制；(3)比较单半脑略占优势时全脑对文字和图像处理的反应；(4)考察了加工速度、抑制和工作记忆任务、强调感觉运动抑制的反扫视任务、阅读广度任务和句子一致性阅读率任务中脑/行为测量的个体差异。为了达到这些目的，我们分析了从18-90岁之间的完整人类头皮上记录的事件相关脑电位（ERPs）以及他们处理文字或图像时的伴随行为。24个实验操作刺激（视觉的，图像的）和情境形态（语言的，图像的），刺激之间关系的本质（范畴的，反义词的），特定项目将被遇到的概率（完形概率），是否，如果是，一个项目在其上下文中的匹配程度，一个项目的约束程度和可预测性，以及在什么水平（词汇的，语义的），输入的视野和任务，或它们的组合。具体的目的是确定正常的衰老是否会改变两个半球敏感的词汇、语义和上下文线索，以及每个半球如何使用它们来访问语义记忆和理解语言。在这样做的过程中，我们验证了(1)我们的假设，即尽管每个人都从情境中受益，但大多数老年人与年轻人不同，不会用情境来预测即将到来的刺激的特征，尽管更强的语言能力可能会弥补这一点；(2)Cabeza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，而这些功能在他们年轻时只负责一个大脑半球的主要职责；(3)众所周知的ERP效应与年龄相关的加工速度和认知功能变化之间的联系。本研究项目将在整个生命周期中完善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对所有年龄的有语义/语言处理障碍的成年人的评估有价值。

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.