Concurrent working memory load can reduce distraction

People have difficulty performing two tasks at once. For example, maintaining items in working memory (WM) makes people more distractible. However, different types of WM load may have different effects on attentional selection depending on whether WM load overlaps with mechanisms involved in target or distractor processing. Three experiments examined the effect of concurrent WM load on Stroop tasks, a widely used measure of executive control and inhibition. Stroop interference increased when the type of WM load overlapped with the type of information required for the target task (experiment 1). In striking contrast, Stroop interference decreased when the type of WM load overlapped with distractor processing (experiment 2). Experiment 3 replicated these results in a different Stroop task. Thus, concurrent WM load does not always impair executive control; performance depends on how contents of WM and task-relevant information overlap. The results highlight how dissociable components of WM interact with perception and executive control.