Semantic Dementia (SD) is a neurodegenerative disease characterised by progressive deterioration of semantic knowledge, resulting in diminished understanding of concepts, whether encountered in verbal or non-verbal form. Over the past three decades, a number of studies employing a range of treatment techniques and learning methods have examined whether patients with SD can relearn previously known concepts or learn and retain new information. In this article, we review this research, addressing two main questions: a) Can aspects of semantic knowledge that are ‘lost’ due to degeneration be re-acquired? b) How much do other memory systems (working and episodic memory) interact with and depend on semantic memory? Several studies demonstrate successful relearning of previously known words and concepts in SD, particularly after regular, prolonged practice; but this success tends to diminish once practice ceases, and furthermore often fails to generalise to other instances of the same object/concept. This pattern suggests that, with impaired semantic knowledge, learning relies to an abnormal extent on perceptual factors, making it difficult to abstract away from the specific visual or other perceptual format in which a given concept has been trained. Furthermore, the impact of semantic ‘status’ of a word or object on both working and episodic memory indicates pervasive interaction of these other memory systems with conceptual knowledge.

中文翻译：

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语义性痴呆患者可以学习（什么）？

语义痴呆（SD）是一种神经退行性疾病，其特征是语义知识进行性恶化，导致对概念的理解减少，无论是口头形式还是非口头形式。在过去三十年中，许多研究采用了一系列治疗技术和学习方法来检验 SD 患者是否可以重新学习以前已知的概念或学习并保留新信息。在本文中，我们回顾了这项研究，解决了两个主要问题：a）由于退化而“丢失”的语义知识的各个方面是否可以重新获得？ b) 其他记忆系统（工作记忆和情景记忆）在多大程度上与语义记忆相互作用并依赖于语义记忆？一些研究表明，在 SD 中可以成功地重新学习以前已知的单词和概念，特别是在定期、长时间的练习之后；但一旦实践停止，这种成功往往会减弱，而且往往无法推广到同一对象/概念的其他实例。这种模式表明，在语义知识受损的情况下，学习会异常程度地依赖于感知因素，因此很难从训练给定概念的特定视觉或其他感知格式中抽象出来。此外，单词或物体的语义“状态”对工作记忆和情景记忆的影响表明这些其他记忆系统与概念知识的普遍相互作用。