SEMANTIC MEMORY AND ALZHIEMER'S DISEASE

语义记忆是指获得的类属知识，包括知识 事实、概念和词义。 阿尔茨海默病（AD）结果 在语义记忆的逐步破坏中， 对理解力、事件记忆力、思考力的破坏性影响， 计划和沟通。该建议旨在澄清 AD引起的语义记忆中断的性质。 项目 指导并旨在进一步发展一个普遍的认知 被称为MEM的架构（约翰逊，1983年，出版社a，B;约翰逊和赫斯特， Press）。 MEM是一个理论框架，用于理解正常的 记忆和功能的破坏，例如，在妄想症中， 虚构症和失忆症 根据MEM，内存是在 最全局的功能水平分为两大系统，一是知觉记忆 系统和反射存储器系统。 在这个框架中，语义 记忆是由感知和反射系统支持的。 的 AD中的普遍认知缺陷被假设是由 反射系统的中断，尤其是 执行议程征聘其他部门的能力 过程（cf. Nebes，1989年）。基于AD的这种特征，我们 期望概念之间的潜在结构关系（例如，一只狗， 是动物）和概念的属性（例如，汽车有发动机） 可能会保持完整，但患者越来越难以 在认知任务中使用这些信息， 其使用的核心被破坏。 实验提出， 评估AD对语义的可用性和使用的影响 各种类型的信息。 将从以下方面获得一致的证据： 几个任务，包括语义关系的验证（例如，是一 麻雀是鸟吗？），善良或重要性的判断（例如， 这是 更核心的概念，汽车，发动机或轮毂罩？），命名 对象和自由联想。 这些研究也将提供有用的 用于识别AD中受损脑区的认知功能的数据 (e.g.,货车Hoesen和Damasio，1987年）。

Semantic memory refers to acquired generic knowledge, including knowledge of facts, concepts, and word meanings. Alzheimer's disease (AD) results in a progressive disruption in semantic memory that ultimately has a devastating effect on comprehension, memory for events, thinking, planning, and communicating. This proposal is directed at clarifying the nature of the disruption in semantic memory produced by AD. The project is guided by and intended to further develop a general cognitive architecture called MEM (Johnson, 1983, in press-a,b; Johnson & Hirst, in press). MEM is a theoretical framework for understanding both normal memory and disruption of function, for example, in delusions, confabulation, and amnesia. According to MEM, memory is organized at the most global functional level into two major systems, a perceptual memory system and a reflective memory system. In this framework, semantic memory is supported by both perceptual and reflective systems. The generalized cognitive deficits in AD are hypothesized to result from a disruption of the reflective system, especially a disruption of the ability of executive agendas to recruit other component reflective processes (cf. Nebes, 1989). Based on this characterization of AD, we expect that underlying structural relations among concepts (e.g., a dog, is an animal) and among attributes of concepts (e.g., cars have engines) may remain intact, but patients increasingly have a more difficult time using this information in cognitive tasks because reflective processes central to their use are disrupted. Experiments are proposed that assess the impact of AD on both the availability and use of semantic information of various types. Converging evidence will be obtained from several tasks, including verification of semantic relations (e.g., Is a sparrow a bird?), judgments of goodness or importance (e.g., Which is more central to the concept of a car, engine or hubcaps?), naming objects, and free association. These studies will also provide useful data for identifying the cognitive functions of brain areas damaged in AD (e.g., Van Hoesen & Damasio, 1987).