STRUCTURE AND DETERIORATION OF DECLARATIVE KNOWLEDGE

我们项目的这一部分探讨了陈述性知识和 陈述性知识系统的退化， 器质性脑病 我们试图检验这个假设， 记忆可以被看作是自适应的行为， 分布式、交互式网络模型，而不是传统的 命题网络 我们将通过评估来验证这一假设。 这些模型的模拟是否能够捕捉到 在那些患有 进行性语义痴呆综合症 项目 将采用计算建模和实验 对语义性痴呆患者的调查。 我们将（a）开发一个 一种从接触中学习概念内部表征的模型 代表性命题语句的语料库; B）测试 模型解释赤字的七个关键特征的能力 语义性痴呆患者，包括进行性 概念知识退化，部分剩余知识 即使是严重受影响的概念，保留概念的某些方面， 与其他相关概念共享，类别的可能影响 冗余知识的一致性，频率敏感性， 高频类别坐标作为图片命名中的错误， 内部损失模式高度一致， 测试模型处理现象的能力 正常成年人所表现出的，如原型性，基本 水平和专业知识;采购顺序;以及对领域的敏感性 相关的底层关系信息，而不是表面信息 相似性 然后，我们将开发该模型的第二个版本， 增加命题内容的灵活性， 表示，以便可以存储特定的事实和事件信息 沿着一般概念知识。 我们将测试新的 模型解释事实恶化模式的能力，以及 语义性痴呆患者的情景信息。 的 实验工作将产生用于培训 网络，并测试使用测试模型的充分性， 解释语义退化的模式。 其他目标 实验工作是a）检查内部缺陷的模式 个体患者关于口头可报告的知识， 无需语言表达即可获取的知识。B）评估 具体情况（人、地点）的知识细分， 尊重频率、一致性和类别一致性; 探索语义和情景记忆之间的关系， 语义记忆和言语产生之间的联系 这些测试将 评估各组织之间相互依存的程度， 过程中的问题。

This part of our project explores the declarative knowledge and the deterioration of the declarative knowledge system as a function of organic brain disease. We seek to test the hypothesis that declarative memory can be seen as arising from the behavior of adaptive, distributed, interactive network models, rather than a conventional propositional network. We will test this hypothesis by assessing whether simulations of such models can capture the patterns of spared and impaired performance that are seen in patients suffering from the progressive syndrome of semantic dementia. The project will employ both computational modeling and experimental investigations with semantic dementia patients. We will a) develop a model that learns internal representations of concepts from exposure to a corpus of representative propositional statements; b) test the model~s ability to account for seven key characteristics of the deficits shown by semantic dementia patients, which include progressive deterioration of conceptual knowledge, partial residual knowledge even of severely affected concepts, sparing of aspects of concepts shared with other related concepts, possible effects of category coherence on spared knowledge, frequency sensitivity, occurrence of high-frequency category coordinates as errors in picture naming, and the high degree of consistency in the pattern of loss within and between tasks; c) Test the model~s ability to address phenomena exhibited by normal adults, such as effects of prototypicality, basic level, and expertise; order of acquisition; and sensitivity to domain relevant underlying relational information as opposed to surface similarity. We will then develop a second version of the model to increase the flexibility of the propositional content that can be represented, so that specific fact and event information can be stored along with general conceptual knowledge. We will test the new model's ability to account for pattern of deterioration of fact, and episodic information in semantic dementia patients. The experimental work will generate materials to be used in training the network, and to test use in testing the model~s adequacy in accounting for patterns of semantic deterioration. Additional aims of the experimental work are to a)Examine the pattern of deficits within individual patients with respect to verbally reportable knowledge and knowledge accessible without requiring verbalization. b)Assess the breakdown of knowledge of specific instances (people, places), with respect to frequency, consistency, and category coherence; and explore the relationships between semantic and episodic memory and between semantic memory and speech production. These tests will assess the degree of integration of interdependency among the processes in question.