Section of Experimental Psychopathology, Department of Psychiatry, Centre for Psychosocial Medicine, University of Heidelberg, Voss-Strasse 4, 69115 Heidelberg, Germany.
Neurosci Lett. 2010 Jan 18;469(1):65-9. doi: 10.1016/j.neulet.2009.11.045. Epub 2009 Nov 20.
The present study investigated the neural correlates of working memory maintenance for real objects in contrast to their verbal designations. For this purpose we employed a delayed match-to-sample task using functional magnetic resonance imaging. The conjunction of load effects for objects and for words revealed a common bilateral network with main foci in the ventrolateral prefrontal cortex and the intraparietal sulcus. Load effect for objects in comparison to load effect for words revealed stronger activation of bilateral precuneus, which suggests the use of mental imagery of objects and object features. The opposite comparison load words versus load objects showed premotor and auditory areas to be activated in association with phonological rehearsal. The bilateral common activation indicates overlapping codes for real-world objects and their verbal designations. Importantly, there is also a dissociation between maintenance of words and objects, which indicates that phonological rehearsal and mental imagery are employed to different degrees.
本研究旨在探究真实物体与物体名称在工作记忆维持过程中的神经关联。为此，我们采用功能磁共振成像技术进行了延迟匹配样本任务。物体和物体名称的负荷效应的联合分析揭示了一个共同的双侧网络，主要焦点位于腹外侧前额叶和顶内沟。与物体相比，物体的负荷效应显示双侧楔前叶的激活更强，这表明使用了物体和物体特征的心理意象。相反，与物体相比，词语的负荷效应显示与语音复述相关的运动前区和听觉区被激活。双侧共同激活表明真实世界物体及其名称的代码存在重叠。重要的是，词语和物体的维持之间也存在分离，这表明语音复述和心理意象的使用程度不同。
