Visual working memory capacity and proactive interference

Abstract

Background: Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory task, like verval working memory tasks, are subject ro proactive interference, couple with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggest that visual working memory capacity may be systematically under-estimated. Methodology/Principal Findings: Working memory capacity was probed behaviorally in adult humans both in laboratory settings and via the internet. Several experiment show that although the effects of proactive interference on visual working memory is significant and can last over several trials, it only changes the capacilty estimate by about 15%. Conclusions/Significance: This study futher confirms the sharp limitations on visual working memory capacity, both in absolute terms and relative to verbal working memory. Its is suggested that the future research take these limitations into account in understanding differences across a variety of tasks between human adults, prelinguistic infant and nonlinguistic animals. © 2008 Hartshorne et al.