The ‘default’ mode of cognition involves simulating internal experiences. However, in some contexts, external focus can become captivating enough to act as the default mode. To examine how these orientations relate, we record fMRI activity in thirty-nine participants as they view naturalistic video clips, each one repeated four times in sequence. When instructed to direct attention externally on the video, most mind-wandering occurs on the last repetition and during less engaging clips. When instructed to direct attention internally on breathing, most mind-wandering occurs on the first repetition and for more engaging clips. Inter-subject correlation, within-subject correlation, and general linear models find similar fronto-parietal networks engaged during transitions from automatic to controlled attention across both conditions, indicating greater overlap in internal and external processing than previously assumed. We conclude that whether the automatic draw of attention is internal or external, and whether its disruptors are internal or external, is context-dependent. Automatic orientations of attention arise from the interaction between the individual and their environment. Understanding mind wandering requires accounting for the pull of external stimuli alongside the pull of internal thought.
Christian et al. (Wed,) studied this question.