Exploring Mind Wandering While Driving
Authors: Barragán Daniela , Roberts Daniel M. , Chong Steven D. , Baldwin Carryl L. 
Published: September 2016

Mind wandering while performing various tasks has been shown to increase errors and impair task performance (Smallwood, McSpadden, & Schooler, 2008). Performance decrements elicited by mind wandering occur when attention necessary for the primary task is diverted to task-unrelated thoughts. While these results remain consistent in various domains, it is less understood how driving performance is affected by mind wandering. He Becic, Lee, and McCarley (2011) used a self-caught method to detect mind wandering, finding that variability in vehicle velocity decreased during states of mind wandering compared to attentive states. Other studies using a probe method to detect mind wandering have found that speed was greater during mind wandering (Yanko & Spalek, 2014), or that speed and speed variability were lower during mind wandering (Bencich, Gamboz, Coluccia, & Brandimonte, 2014) compared to attentive states. Although these studies provide some insight about the performance decrements and associated consequences of engaging in mind wandering while driving, the extent that mind wandering affects driving performance is not fully understood. The goal for this research was to further investigate differences in driving performance during mind wandering and attentive states. Participants performed two simulated driving scenarios and were instructed to indicate when they noticed they were just mind wandering (He et al., 2011; Smallwood & Schooler, 2015) by pressing a button on the steering wheel. Episodes of mind wandering were classified as 10 seconds before a button press with a three second buffer and, for comparison, instances of attentiveness relative to mind wandering episodes were classified as 10 seconds after a button press with a three second buffer (He et al., 2011). The results from linear mixed effects models showed that steering reversal rate, lane deviation, and lateral position were significantly greater during attentive states compared to states of mind wandering. These results may best be explained by Michon’s (1985) proposal that driving is a hierarchical task consisting of three levels. The first level includes basic operational control (e.g., speed and lane maintenance), while the higher-order levels are tactical (e.g., interacting with other vehicles, lane changing, etc.) and strategic (e.g., navigation, planning, and decision making). Our data suggest that mind wandering affected but did not necessarily disrupt driving performance. However, the present study only investigated basic operational-level metrics. Mind wandering may be more likely to negatively influence the detection of critical events and hazards–deviations from routine behaviors associated with higher level components of the driving task (i.e., tactical and strategic). For example, Yanko and Spalek (2014) reported that when participants were mind wandering they responded more slowly to critical events while driving. Further research is needed to determine whether the negative effects of mind wandering are more likely to occur within these higher order components of the driving tasks.