Mind-wandering while driving: The impact of fatigue, task length, and sustained attention abilities

Mind-wandering involves a lapse in attention due to preoccupation with one's own thoughts, the experience of which may interfere with performance on a primary task. The goal of this study was to investigate how task length and fatigue influenced the tendency to mind-wander while driving. We were also interested in whether the propensity to mind-wander could be predicted by individual differences in sustained attention, as measured by the Sustained Attention to Response Task (SART). Participants completed three 20-25 min drives, during which time pre-recorded thought-probes prompted participants to answer whether they were thinking of driving. Mind-wandering was measured both during the drive (in terms of the percentage of thought-probe trials where drivers reported that they were not thinking of driving), as well post-task (in terms of self-rated difficulty in focusing attention). Driving speed, steering variability and hazard response time were measured by the driving simulator, and drivers also rated their performance post-task. There were significant increases in self-rated difficulty focusing with time on task, and non-significant increases in reported mind-wandering. Driving speeds and steering variability also increased with time on task, but individual differences in sustained attention as measured by the SART did not predict these changes. Overall, the best advance predictor of mind-wandering was the number of hours of sleep the previous night. Mind-wandering and difficulty focusing were correlated with negative emotional rumination (e.g., worries, guilt, anger), though it is unclear whether negative emotionality causes mind-wandering or vice versa. This research has implications for both basic and applied research on individual differences and cognitive distraction, as well as practical safety implications in areas of driver training and autonomous vehicle development.