Giffard Bénédicte, Laisney Mickaël, Mézenge Florence, de la Sayette Vincent, Eustache Francis, Desgranges Béatrice
Inserm - EPHE - Université de Caen/Basse-Normandie, U923, GIP Cyceron, CHU Côte de Nacre, 14033 Caen Cedex, France.
Neuropsychologia. 2008;46(6):1657-66. doi: 10.1016/j.neuropsychologia.2007.12.031. Epub 2008 Jan 31.
The neural substrates responsible for semantic dysfunction during the early stages of AD have yet to be clearly identified. After a brief overview of the literature on normal and pathological semantic memory, we describe a new approach, designed to provide fresh insights into semantic deficits in AD. We mapped the correlations between resting-state brain glucose utilisation measured by FDG-PET and semantic priming scores in a group of 17 AD patients. The priming task, which yields a particularly pure measurement of semantic memory, was composed of related pairs of words sharing an attribute relationship (e.g. tiger-stripe). The priming scores correlated positively with the metabolism of the superior temporal areas on both sides, especially the right side, and this correlation was shown to be specific to the semantic priming effect. This pattern of results is discussed in the light of recent theoretical models of semantic memory, and suggests that a dysfunction of the right superior temporal cortex may contribute to early semantic deficits, characterised by the loss of specific features of concepts in AD.
在阿尔茨海默病（AD）早期阶段导致语义功能障碍的神经基质尚未被明确识别。在简要概述了关于正常和病理性语义记忆的文献后，我们描述了一种新方法，旨在为AD中的语义缺陷提供新的见解。我们绘制了一组17名AD患者通过氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）测量的静息态脑葡萄糖利用与语义启动分数之间的相关性。启动任务由共享属性关系的相关词对（例如老虎 - 条纹）组成，它能对语义记忆进行特别纯粹的测量。启动分数与双侧颞上区的代谢呈正相关，尤其是右侧，并且这种相关性被证明是特定于语义启动效应的。根据最近的语义记忆理论模型对这一结果模式进行了讨论，结果表明右侧颞上皮质功能障碍可能导致AD早期语义缺陷，其特征是概念的特定特征丧失。
