Dissociation of storage and rehearsal in verbal working memory: Evidence from positron emission tomography

Current cognitive models of verbal working memory include two components: a phonological store and a rehearsal mechanism that refreshes the contents of this store. We present research using positron emission tomography (PET) to provide further evidence for this functional division. In Experiment 1, subjects performed a valiant of Sternberg's (1966) item recognition task. Experiment 2 used a continuous memory task with control conditions designed to separate the brain regions underlying storage and rehearsal. The results show that independent brain regions mediate storage and rehearsal. In Experiment 3, a dual-task procedure supported the assumption that these memory tasks elicited a rehearsal strategy.