Left superior parietal lobe mediates the link between spontaneous mind-wandering tendency and task-switching performance.

While increasing studies have documented the link between mind wandering and task switching, less is known about which brain regions mediate this relationship. Using the MPI-Leipzig Mind-Brain-Body dataset (N = 173), we investigated the association between trait-level tendencies of mind wandering, task-switching performance, structural connectivity, and resting-state functional connectivity. At the behavioral level, we found that higher spontaneous mind-wandering trait scores were associated with shorter reaction times on both repeat and switch trials. The whole brain cortical thickness analysis revealed a strong mediating role of the left superior parietal lobe, which is part of the dorsal attention network, in the link between spontaneous mind-wandering tendency and task-switching performance. The resting-state functional connectivity analysis further demonstrated that this association was partly mediated by the negative dorsal attention network-default mode network functional connectivity. No significant mediating effects were found for deliberate mind-wandering tendency. Overall, the findings highlight the pivotal role of the left superior parietal lobe in activating new mental set during mind-wandering and task-switching processes, providing another evidence in favor of a role for switching in mind wandering.

Commonalities between mind wandering and task-set switching: An event-related potential study.

Previous research has established that mind wandering does not necessarily disrupt one's task-switching performance. Here we investigated the effects of mind wandering on electrophysiological signatures, measured using event-related potentials (ERPs), during a switching task. In the current study, a final sample of 22 young adults performed a task-switching paradigm while electroencephalography was continuously recorded; mind wandering was assessed via thought probes at the end of each block. Consistent with previous research, we found no significant disruptive effects of mind wandering on task-switching performance. The ERP results showed that at the posterior electrode sites (P3, Pz, and P4), P3 amplitude was higher for mind-wandering switch trials than on-task switch trials, thus opposing the typical pattern of P3 attenuation during periods of mind wandering relative to on-task episodes. Considering that increased P3 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 executive control processes underlie mind wandering and task-set switching, providing further evidence in favor of a role for switching in mind wandering.

Reconceptualizing mind wandering from a switching perspective.

Mind wandering is a universal phenomenon in which our attention shifts away from the task at hand toward task-unrelated thoughts. Despite it inherently involving a shift in mental set, little is known about the role of cognitive flexibility in mind wandering. In this article we consider the potential of cognitive flexibility as a mechanism for mediating and/or regulating the occurrence of mind wandering. Our review begins with a brief introduction to the prominent theories of mind wandering-the executive failure hypothesis, the decoupling hypothesis, the process-occurrence framework, and the resource-control account of sustained attention. Then, after discussing their respective merits and weaknesses, we put forward a new perspective of mind wandering focused on cognitive flexibility, which provides an account more in line with the data to date, including why older populations experience a reduction in mind wandering. After summarizing initial evidence prompting this new perspective, drawn from several mind-wandering and task-switching studies, we recommend avenues for future research aimed at further understanding the importance of cognitive flexibility in mind wandering.

Spontaneous mind-wandering tendencies linked to cognitive flexibility in young adults.

Despite that previous studies have investigated mind wandering using task-switching paradigms, the association between the tendency to mind wander and cognitive flexibility remains largely unexplored. The present study investigated the relationship between self-reported spontaneous mind-wandering tendencies and task-switching performance in young adults. Seventy-nine university students performed a forced task-switching and a voluntary task-switching paradigm and then completed a battery of questionnaires. The results showed that compared to participants with lower spontaneous mind-wandering tendencies, participants with higher spontaneous mind-wandering tendencies demonstrated better performance (evidenced by smaller switch cost reaction times) in the forced task-switching paradigm despite indicating more mind wandering during task performance. Performance on the voluntary task-switching paradigm, on the other hand, did not differ between the two groups. The findings in the forced task-switching paradigm indicate a link between mind wandering and cognitive flexibility, thus providing initial evidence in favor of a role for switching in mind wandering.