This research was supported by the Experimental Psychology Society, UK, and the Belgian National Fund for Scientific Research. We thank Dean Salisbury and two anonymous reviewers for their constructive comments and suggestions.
An electrophysiological measure of visual short-term memory capacity within and across hemifields
Version of Record online: 4 AUG 2010
Copyright © 2010 Society for Psychophysiological Research
Volume 48, Issue 3, pages 333–336, March 2011
How to Cite
Delvenne, J.-F., Kaddour, L. A. and Castronovo, J. (2011), An electrophysiological measure of visual short-term memory capacity within and across hemifields. Psychophysiology, 48: 333–336. doi: 10.1111/j.1469-8986.2010.01079.x
- Issue online: 9 FEB 2011
- Version of Record online: 4 AUG 2010
- (Received December 1, 2009; Accepted May 8, 2010)
- Visual working memory;
- Visual short-term memory;
- Capacity limits;
- Bilateral presentation;
- Event-related potentials
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.