Mind-Wandering and Driving: Comparing Thought Report and Individual Difference Measures

Mind-wandering is a cognitive state in which attention is diverted from the main task and towards more personal thoughts, which can interfere with performance. This study investigated differences in patterns of mind-wandering and driving performance measured during thought-probe versus post-task selfreport conditions, and further differentiated based on individual differences in working memory—as measured by the Operation Span (OSPAN) and Sustained Attention to Response Task (SART). Participants completed two 30-minute drives. Those in the thought-probe condition were asked whether they were thinking of driving; the proportion of trials where they answered “no” was used as the index of mind-wandering. In the post-task condition participants estimated the percentage of time they had mind-wandered during each drive. Speed, steering variability, headway distance, and hazard response time to a lead vehicle braking were also measured. Results showed that the magnitude of mind-wandering captured in the thought-probe condition was greater than in the post-task condition, though hazard response times were also faster despite greater mindwandering reports. Higher OSPAN scores were associated with greater reports of mind-wandering, but only in the post-task condition. Conversely, in the post-task condition those with low SART scores responded slower to hazards than those with high scores; in the thought-probe condition these groups did not differ. Findings indicate a differential impact of report-type on participant experience, emphasizing the need for more covert measures of mind-wandering—e.g., eyetracking or electroencephalography—that provide accurate estimates of task engagement but don’t interfere with task flow.