Why the global availability of mind wandering necessitates resource competition: Reply to McVay and Kane (2010).

When the mind wanders, conscious thoughts come to mind that are only loosely related to the task being performed. This phenomenon produces tension within the cognitive sciences because the interfering nature of these thoughts is at odds with the assumption that such processes are functional in daily life. In their comment, McVay and Kane (2010) suggested that failures in executive control can create the conditions that favor mind wandering—a control-failure hypothesis that questions whether mind wandering consumes resources. Whether mind wandering always occurs following a control failure, it is always a conscious reportable experience and so is globally available to the system. Such global availability suggests that mind wandering does indeed demand resources, in particular access to a global workspace that supports conscious experience. Although the control-failure view explains the transient occurrence of mind wandering during demanding tasks, the global availability hypothesis is consistent with all mind wandering, regardless of context; it is implied by many features of the argument proposed by McVay and Kane (2010). Consideration of these issues leads to the conclusion that when the mind wanders, specific information from the default mode becomes globally available to the system; in this respect, mind wandering is resource demanding inasmuch as it occupies the global workspace necessary for consciousness.