Institute of Psychological Sciences, University of Leeds, United Kingdom.
Psychophysiology. 2011 Mar;48(3):333-6. doi: 10.1111/j.1469-8986.2010.01079.x.
Recent electrophysiological research has identified a specific contralateral correlate of the contents of visual short-term memory (VSTM). This posterior contralateral delay activity (CDA) persists during the retention period, and its amplitude is modulated by the number of items held at any one time. Here we show that, despite the contralateral nature of this activity, its amplitude is modulated by the number of objects from both hemifields. When objects from one side of the visual field are held in memory, CDA activity increased for arrays of one, two, and three objects, but stopped getting larger for arrays of four objects. However, when objects from both sides are memorized at the same time, CDA activity reached its asymptotic limit for arrays of two objects per side. These results suggest that, in spite of being contralaterally organized, VSTM is limited by the number of objects from both hemifields.
最近的电生理学研究已经确定了视觉短期记忆（VSTM）内容的一个特定的对侧相关物。这种对侧延迟活动（CDA）在保持期内持续存在，其幅度被同时保持的项目数量所调制。在这里，我们表明，尽管这种活动具有对侧性质，但它的幅度被来自两个半视野的物体数量所调制。当来自视野一侧的物体被记忆时，CDA 活动增加了一个、两个和三个物体的数组，但对于四个物体的数组不再增加。然而，当两侧的物体同时被记忆时，CDA 活动达到了两侧各两个物体的渐近极限。这些结果表明，尽管是对侧组织的，VSTM 受到来自两个半视野的物体数量的限制。
