a condition in which thoughts do not remain focused on the task at hand but range widely and spontaneously across other topics. It tends to occur during tasks that do not require sustained attention. Mind wandering cannot be scientifically quantified but has been studied using thought sampling and questionnaires. Research questions include how much mind wandering is a stable personality trait, how much it is linked to mood and situation, and how it relates to processing capacity and working memory. The contents of mind wandering are often referred to as task-unrelated thoughts (TUTs), task-unrelated images and thoughts (TUITs), or stimulus-independent and task-unrelated thoughts (SITUTs). See also absent-mindedness; intrusive thoughts.