AGE-RELATED ERP MEASURES IN ALZHEIMER'S DISEASE

与失配负性（MMN）的研究表明， 信息封装系统，可能也依赖于主系统 作为听觉关联皮层，它检测最近的听觉变化 自动的，预先注意的基础上。相比之下，早期和晚期的ERP信号 控制的、选择性的注意力（处理消极情绪; PN），接收输入 从一个广泛的注意力网络依赖于听觉颞顶叶 和额叶皮质联合区。据推测，MMN 系统在两种类型的记忆上运行：1）存储在感觉记忆中的原始输入 (e.g.,音高和强度），以及2）在 最近的过去，这需要记忆的基础上转变的原始感官 输入.系统的学习能力，以及基于抽象或抽象的信息形成痕迹的能力。 概念刺激的特点，促使研究人员提出， MMN所基于的记忆与“内隐记忆”的共同点比 它与感官记忆有关。因此，这一领域的研究是一个自然的 扩展研究者先前的间接记忆研究， 老年痴呆症患者。有选择地参加的要求 企业资源规划系统的早期和后期组成部分， 基于表征所关注频道中的刺激的属性的刺激， 并有选择地重复这些属性。本提案的主要重点是 更好地理解听觉注意机制， 阿尔茨海默病（PAD）。神经病理学数据表明，初级听觉 皮质，在其上产生MMN到简单的物理差异 视情况而定，在PAD中是完整的，而颞顶叶和额叶联合 早期和晚期PN所依赖的区域在PAD中受到损害。这些数据 导致预期ERP标志着前注意听觉机制 基于原始感觉输入，在轻度和中度 痴呆患者，而那些基于原始输入的转换的患者可以 没有同样，ERP标志着对单一位置线索的选择性注意， 在PAD中可能相对完整，而基于联合特征的那些将 没有将从62个头皮放置记录ERP，以确定 是否MMN和PN分量头皮分布，并通过暗示，其 潜在的神经源，在患者和 对照组和/或实验条件。数据将是相关的 到前注意处理，基于复杂特征的选择性注意， 这些机制中与年龄相关的病理变化，及其生理 基础

Research with the mismatch negativity (MMN) has revealed an informationally encapsulated system, presumably dependent upon primary as well as auditory association cortex, that detects change in the recent acoustic past on an automatic, preattentive basis. By contrast, early and late ERP signs of controlled, selective attention (processing negativities; PN), receive inputs from a widespread attentional network dependent upon auditory temporo-parietal and frontal cortical association areas. It has been hypothesized that the MMN system operates on two types of memories: 1) raw input stored in sensory memory (e.g., pitch and intensity), and 2) representations of invariances in the recent past, which entail memories based on transformations of the raw sensory input. The system's ability to learn, and to form traces based on abstract or conceptual stimulus features, has promoted investigators to suggest that the memory on which the MMN is based has more in common with "implicit memory" than it does with sensory memory. Therefore, this area of research is a natural extension of the investigator's previous indirect memory studies with Alzheimer's disease patients. The requirement to selectively attend gives rise to early and late ERP components that reflect, respectively, selection of stimuli based on attributes that characterize stimuli in the attended channel, and selective rehearsal of these attributes. The major focus of this proposal is on a better understanding of auditory attentional mechanisms in probable Alzheimer's disease (PAD). Neuropathological data suggest that primary auditory cortex, upon which the generation of MMNs to simple physical differences depends, is intact in PAD, whereas temporo-parietal and frontal association areas, upon which early and late PNs depend, are damaged in PAD. These data lead to the expectation that ERP signs of pre-attentive auditory mechanisms based on raw sensory input may be relatively intact in mild and moderately demented patients, whereas those based on transformations of the raw input may not. Similarly, ERP signs of selective attention for a single, location, cue may be relatively intact in PAD, whereas those based on conjoint features will not. ERPs will be recorded from 62 scalp placements in order to determine whether MMN and PN component scalp distributions and by implication, their underlying neural sources, differ systematically between the patient and control groups and/or conditions of the experiments. The data will be relevant to preattentive processing, selective attention based on complex features, age-related pathological changes in these mechanisms, and their physiological underpinnings.