AGE-RELATED ERP MEASURES IN ALZHEIMER'S DISEASE

关于失配负值(MMN)的研究揭示了 信息封装的系统，想必也依赖于主服务器 作为听觉联想皮层，它检测到最近声学过去的变化 在自动的、预先注意的基础上。相比之下，早期和晚期的ERP迹象 受控的选择性注意(处理消极情绪；PN)，接受输入 从依赖于听觉的颞顶叶的广泛注意网络 和额叶皮质关联区。据推测，MMN 系统对两种类型的记忆进行操作：1)存储在感觉记忆中的原始输入 (例如，音调和强度)，以及2) 最近的过去，这需要基于原始感官转换的记忆 输入。系统的学习能力，以及基于抽象或 概念刺激特征，促使研究人员提出， MMN所基于的记忆与内隐记忆有更多的共同之处 它与感官记忆有关。因此，这一领域的研究是理所当然的 研究人员先前的间接记忆研究的扩展 阿尔茨海默病患者。有选择地参加的要求产生了 分别反映选择的早期和晚期企业资源规划组件 基于表征参与通道中的刺激的属性的刺激， 以及对这些属性的选择性排练。这项提案的主要焦点是 是基于对听觉注意机制的更好的理解 阿尔茨海默病(PAD)。神经病理数据表明，初级听觉 大脑皮质，在此基础上产生的MMN要有简单的物理差异 视情况而定，在PAD中是完整的，而颞顶和额叶的联系 早期和晚期PNS所依赖的区域在PAD中受损。这些数据 这导致了一种期望，即事件相关电位的信号是预先注意的听觉机制 基于原始的感觉输入可能在轻度和中度时相对完整 精神错乱患者，而那些基于原始输入的转换可能 不。同样，事件相关电位表示对单一、位置、线索的选择性注意 可能在PAD中相对完整，而基于连接特征的那些将 不。将从62个头皮放置记录事件相关电位，以便确定 MMN和PN成分的头皮分布及其隐含的 潜在的神经来源，在患者和 对照组和/或实验条件。数据将是相关的 到前注意加工，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，以及它们的生理变化 支撑点。

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.