Cognitive load combined with the loss of exogenous cues, which can occur when the driver briefly glances away from the roadway, may undermine driving performance, particularly drivers' ability to detect safety-critical events. This study investigates the effect of cognitive load on guidance of visual attention. In each of two experiments, 12 participants engaged in an auditory task while performing a change detection task. A change blindness paradigm was implemented to mask exogenous cues by periodically blanking the screen in a driving simulator while a change occurred. Performance measures included participants' sensitivity to vehicle changes and confidence in detecting them. Results showed that cognitive load uniformly diminished participants' sensitivity and confidence, independent of safety relevance or lack of exogenous cues. Periodic blanking, which simulated glances away from the roadway, undermined change detection to a greater degree than did cognitive load; however, drivers' confidence in their ability to detect changes was diminished more by cognitive load than by periodic blanking. The findings indicate that cognitive load and short glances away from the road are additive in their tendency to increase the likelihood of drivers missing safety-critical events. These results have implications for the design and use of in-vehicle information devices.
Samenvatting