Unexpected costs of high working memory capacity following directed forgetting and contextual change manipulations.

Greater working memory capacity is usually associated with greater ability to maintain information in the face of interruptions. In two experiments, we found that some types of interruptions actually lead to greater forgetting among high-span people than among low-span people. Specifically, an instruction designed to change mental context resulted in significant forgetting for high-span people but minimal forgetting among the low-span people. Intentional forgetting instructions also resulted in greater forgetting among higher working memory capacity participants than among lower working memory capacity participants. A candidate explanation called the intensified context shift hypothesis is proposed which suggests that high-span people are more context dependent than low-span people.