School of Psychology, Laval University, Quebec City, Quebec, Canada; Laboratoire d'Étude des Mécanismes Cognitifs, University Lyon 2, Bron Cedex, France.
Cortex. 2013 Oct;49(9):2402-15. doi: 10.1016/j.cortex.2012.10.010. Epub 2012 Dec 5.
Implicit memory is generally supposed to be preserved in Alzheimer's disease (AD). Yet, some implicit priming effects are impaired and others are not. The preserved/impaired priming effects are often interpreted according to the perceptual/conceptual or identification/production distinctions. Perceptual-identification priming paradigms shall be preserved and conceptual-production priming paradigms impaired. A third interpretation is yet possible based on the disconnection syndrome hypothesis which states that patients with AD should fail tasks requiring relatively complex brain communications. In this case, patients with AD should not demonstrated a significant perceptual priming effect in an identification task if this one involved complex brain communications. The present study tests this latter hypothesis with two cross-modal priming experiments using a categorization task. A visual meaningless mask presented with half of the auditory primes tested the nature of the cross-modal priming effect. The control group exhibited significant priming effects for unmasked primes. The interference effect of the mask demonstrated that the priming effect was perceptually driven. Patients with AD did not present any priming effect nor mask interference. The present findings therefore showed that perceptual priming using an identification task could be impaired in AD supporting the disconnection syndrome hypothesis.
内隐记忆通常被认为在阿尔茨海默病（AD）中得到保留。然而，一些内隐启动效应受损，而另一些则没有。保留/受损的启动效应通常根据知觉/概念或识别/产生的区别来解释。知觉-识别启动范式应得到保留，而概念-产生启动范式则受到损害。还有一种基于分离综合征假说的解释，该假说指出，AD 患者应该无法完成需要相对复杂大脑通讯的任务。在这种情况下，如果识别任务涉及复杂的大脑通讯，AD 患者不应表现出显著的知觉启动效应。本研究使用分类任务通过两个跨模态启动实验来检验这后一种假说。一个视觉无意义的掩蔽与一半的听觉启动同时呈现，测试了跨模态启动效应的性质。对照组对未掩蔽的启动表现出显著的启动效应。掩蔽的干扰效应表明，启动效应是由知觉驱动的。AD 患者既没有表现出任何启动效应，也没有表现出掩蔽干扰。因此，本研究结果表明，使用识别任务的知觉启动可能在 AD 中受损，支持分离综合征假说。
