Abstract
Mind wandering is a phenomenon in which our attention shifts away from the task at hand toward task-unrelated thoughts. Although a number of studies have investigated mind wandering using task-switching paradigms, which are widely used experimental paradigms to measure cognitive flexibility, no previous study, to my knowledge, has linked the mind-wandering tendency to cognitive flexibility. This is perplexing, as mind wandering inherently involves a shift in mental set. In this dissertation I examined the relationships between the tendency to mind wander and cognitive flexibility, as well as the other two executive functions that are crucial to the switching processes (i.e., inhibitory control, which inhibits previously relevant thoughts and actions, and working memory, which activates newly relevant thoughts and actions). After introducing the background and research approach in Chapter 1, I put forth in Chapter 2 the argument that instances of mind wandering are in fact instances of mental set shifting. This argument provides the framework for the switching perspective of mind wandering investigated in the subsequent experimental chapters.
In Study 1 (Chapter 3), I investigated the links between spontaneous mind-wandering tendencies and cognitive flexibility. I found that healthy young adults with higher self-reported spontaneous mind-wandering tendencies, who also indicated more mind wandering during switching tasks, demonstrated better switching performance than those with lower self-reported spontaneous mind-wandering tendencies. These findings provided initial evidence in favor of a role for switching in mind wandering.
In Study 2 (Chapter 4), I investigated the links between spontaneous mind-wandering tendencies and three executive functions (i.e., cognitive flexibility, working memory, and inhibitory control). I found no difference in any of the executive function tasks between the high and low spontaneous mind-wandering tendency groups despite participants with higher spontaneous mind-wandering tendencies indicating more mind wandering during task performance. I discussed possible factors that may contribute to these findings (e.g., participants in the current study remaining more focused on the task at hand and minimizing the occurrence of mind wandering) and suggested directions for future research.
In Study 3 (Chapter 5), I examined the similarities between the neural signatures of mind wandering and task-set switching using electroencephalography (EEG). I found that during task-set switching, correct mind-wandering switch trials involved more mental processes and/or executive control resources than correct on-task switch trials (evidenced by higher P300 amplitude); this effect of mind wandering on the electrophysiological data occurred despite reaction times being similar. In consideration of recent research suggesting that increased P300 amplitude during higher-order switch trials (e.g., response rule switching) may reflect the implementation of new higher-order task sets/rules, the current findings seem to indicate similar, yet distinguishable, executive control processes underlie mind wandering and task-set switching.
The implications of these three experimental studies (e.g., cognitive flexibility may play an important role in mind wandering) and their relation to previous research are discussed in Chapter 6. Overall, I argue that: (a) mind wandering is not necessarily a negative phenomenon and might be managed effectively if one has superior switching abilities; and (b) by investing in further research into the switching account of mind wandering put forward in this dissertation, researchers may ultimately arrive at a definition of mind wandering that fits better with the experimental findings to date and can gain consensus in the field.