The frequency of mind wandering increases over time during ongoing task performance

Attention has a seemingly inevitable tendency to turn inward towards our thoughts. Mind wandering refers to moments when this inward focus diverts attention away from the task-at-hand. Mind wandering is ubiquitous, having been estimated to occur between 30-50% of our waking moments and proposed to increase in frequency with time during ongoing task performance. Yet, it is unclear whether mind wandering systematically increases with time-on-task for a broad range of tasks, or if there is heterogeneity in the magnitude of within-task change in mind wandering. We conducted a systematic literature search and individual participant data (IPD) meta-analysis of rates of occurrence of mind wandering during task performance. Our search located 57 research articles providing roughly 400,000 total responses to experience sampling mind wandering probes from more than 10,000 unique individuals. Latent growth curve models estimated the initial occurrence of mind wandering and linear change in mind wandering over sequential probes for each study sample, and effects were summarized using multivariate meta-analysis. Our results confirm that mind wandering increases in frequency over time during task performance, implicating mind wandering in characteristic patterns of worsening behavioral performance with time-on-task known as the vigilance decrement. The systematic search and meta-analysis further provide the most comprehensive assessment of normative rates of mind wandering during task performance reported to date.