Drew Trafton W, McCollough Andrew W, Vogel Edward K
Department of Psychology, University of Oregon, Eugene 97403-1227, USA.
Clin EEG Neurosci. 2006 Oct;37(4):286-91. doi: 10.1177/155005940603700405.
Visual working memory is a limited capacity system that temporarily maintains information about objects in the immediate visual environment. Psychophysical experiments have shown that most people are able to actively maintain 3 or 4 items in visual working memory at any point in time. To better understand how this process works and why our working memory capacity is so limited, a variety of neurophysiological approaches have been employed. In recent years, there has been a surge of interest in understanding how visual information is maintained in working memory at the neural level. Single-cell research with nonhuman primates has shown that neuronal firing during the retention period reflects the information that is currently held in working memory. In humans, event-related potentials (ERPs) have been used to examine the maintenance of information in working memory. An event-related potential component, known as the negative slow wave (NSW), has been used to measure the maintenance of information in working memory "online" during a given trial. More recently, another ERP component, the contralateral delay activity (CDA) has been shown to be a fairly specific correlate of the current contents of working memory. This component is sensitive to an individual's working memory capacity and may provide a window into the operations of this central cognitive construct.
视觉工作记忆是一个容量有限的系统，它暂时维持关于即时视觉环境中物体的信息。心理物理学实验表明，大多数人在任何时刻都能够在视觉工作记忆中主动维持3或4个项目。为了更好地理解这个过程是如何运作的，以及为什么我们的工作记忆容量如此有限，人们采用了各种神经生理学方法。近年来，人们对在神经层面理解视觉信息如何在工作记忆中维持的兴趣激增。对非人类灵长类动物的单细胞研究表明，在保持期的神经元放电反映了当前工作记忆中所保存的信息。在人类中，事件相关电位（ERP）已被用于研究工作记忆中信息的维持。一种被称为负慢波（NSW）的事件相关电位成分，已被用于在给定试验期间“在线”测量工作记忆中信息的维持。最近，另一种ERP成分，即对侧延迟活动（CDA），已被证明是工作记忆当前内容的一个相当特异的相关指标。这个成分对个体的工作记忆容量敏感，可能为洞察这个核心认知结构的运作提供一个窗口。
