Detecting and Quantifying Mind Wandering during Simulated Driving

Abstract

Mind wandering is a pervasive threat to transportation safety, potentially accounting for a substantial number of crashes and fatalities. In the current study, mind wandering was induced through completion of the same task for 5 days, consisting of a 20-min monotonous freeway-driving scenario, a cognitive depletion task, and a repetition of the 20-min driving scenario driven in the reverse direction. Participants were periodically probed with auditory tones to self-report whether they were mind wandering or focused on the driving task. Self-reported mind wandering frequency was high, and did not statistically change over days of participation. For measures of driving performance, participant labeled periods of mind wandering were associated with reduced speed and reduced lane variability, in comparison to periods of on task performance. For measures of electrophysiology, periods of mind wandering were associated with increased power in the alpha band of the electroencephalogram (EEG), as well as a reduction in the magnitude of the P3a component of the event related potential (ERP) in response to the auditory probe. Results support that mind wandering has an impact on driving performance and the associated change in driver's attentional state is detectable in underlying brain physiology. Further, results suggest that detecting the internal cognitive state of humans is possible in a continuous task such as automobile driving. Identifying periods of likely mind wandering could serve as a useful research tool for assessment of driver attention, and could potentially lead to future in-vehicle safety countermeasures.

Keywords: EEG; alpha; driving; inattention; mind wandering.

Figure 1

Schematic of the simulated drive (A), and a screen shot of the simulated drive environment (B).

Figure 2

Labeling of data for analysis.

Figure 3

The percentage of attentional probes in which participants responded “mind wandering” (top), and the percentage of “mind wandering” responses that were subsequently categorized as “aware” (bottom), over days and drives.

Figure 4

Linear mixed model interaction between attentional state (“mind wandering”, “on task”) and days (1–5) as predictors of speed variability, p = 0.009.

Figure 5

Means and standard errors of lane deviation for “mind wandering” and “on task” attentional states.

Figure 6

Means and standard errors of the standard deviation of lateral position (SDLP) for “mind wandering” and “on task” attentional states.

Figure 7

Means and standard errors of steering reversal rate (SRR; per second) for “mind wandering” and “on task” attentional states.

Figure 8

Electroencephalography (EEG) power spectrum at parietal electrode site Pz, preceding “mind wandering” vs. “on task” responses. The shaded gray region represents the width of the frequency bin defined as alpha, identified via inspection of the grand mean of both “mind wandering” and “on task” conditions.

Figure 9

Topography of alpha power preceding “mind wandering” vs. “on task” responses. The right-most panel represents the topography of the difference between “mind wandering” and “on task” responses.

Figure 10

Event related potential (ERP) at electrode Fz to auditory probe tones, separated by participant response and the drive number in which the probe tone occurred. The shaded gray region represents the time-window used to evaluate P3a amplitude. Probe tones presented during periods in which participants responded “on task” have a greater magnitude of P3a relative to probes presented during periods in which participants responded “mind wandering”. In addition, probe tones presented during the first drive of the day have a greater magnitude of P3a relative to probes presented during the second drive of the day.

Figure 11

Topography of the ERP to the auditory probe tone, for “mind wandering” vs. “on task” responses, averaged within the 200–400 ms P3a window following probe onset, collapsed across all days and drives. The right-most panel represents the topography of the difference between “mind wandering” and “on task” responses.