Department of Child and Adolescent Mental Health, University of Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany.
Neurosci Lett. 2010 Sep 27;482(2):172-6. doi: 10.1016/j.neulet.2010.07.030. Epub 2010 Jul 17.
The objective of the study was to investigate neuronal processing during the encoding, retention and retrieval phases of a serial visual working memory task. Particularly, we were interested in how these phases are affected by working memory load and how processing is modulated by methylphenidate. Healthy adults were asked to memorize the order of four, five or six pictures under methylphenidate (20mg) and under placebo while brain electrical activity was recorded. On the performance level, the number of correct responses decreased with increasing working memory load. Concerning brain electrical activity, in the encoding phase P3 amplitudes increased at midline electrodes with increasing memory load while load had no effect in the retention and retrieval phase. Medication neither influenced performance nor the different processing stages significantly. Our data provide evidence that during the encoding phase more attentional resources are allocated in trials with higher load as reflected by larger P3 amplitudes.
本研究旨在探究序列视觉工作记忆任务的编码、保持和提取阶段的神经元处理过程。特别地，我们感兴趣的是这些阶段如何受到工作记忆负荷的影响，以及加工过程如何被哌甲酯调节。健康成年人被要求在服用哌甲酯（20mg）和安慰剂的情况下，记住四张、五张或六张图片的顺序，同时记录大脑电活动。在表现水平上，随着工作记忆负荷的增加，正确反应的数量减少。关于大脑电活动，在编码阶段，随着记忆负荷的增加，中线电极的 P3 振幅增加，而在保持和提取阶段，负荷没有影响。药物既没有显著影响表现，也没有显著影响不同的加工阶段。我们的数据提供了证据，表明在编码阶段，随着负荷的增加，分配更多的注意力资源，这反映在更大的 P3 振幅上。
