A working memory system with distributed executive control

Working memory consists of domain-specific storage facilities and domain-general executive control processes. In some working memory theories, these control processes are accounted for via a homunculus, the central executive. In the present article, the author defends a mechanistic view of executive control by adopting the position that executive control is situated in the context of goal-directed behavior to maintain and protect the goal and to select an action to attain the goal. On the basis of findings in task switching and dual tasking, he proposes an adapted multicomponent working memory model in which the central executive is replaced by three interacting components: an executive memory that maintains the task set, a collection of acquired procedural rules, and an engine that executes the procedural rules that match the ensemble of working memory contents. The strongest among the rules that match the ensemble of working memory contents is applied, resulting in changes of the working memory contents or in motor actions. According to this model, goals are attained when the route to the goals is known or can be searched when the route is unknown (problem solving). Empirical evidence for this proposal and new predictions are discussed