Visual Attention in Driving: The Effects of Cognitive Load and Visual Disruption

OBJECTIVE This study investigates the effect of cognitive load on guidance of visual attention. BACKGROUND Previous studies have shown that cognitive load can undermine driving performance, particularly drivers' ability to detect safety-critical events. Cognitive load combined with the loss of exogenous cues, which can occur when the driver briefly glances away from the roadway, may be particularly detrimental. METHOD In each of two experiments, twelve 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 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 road-way, 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. CONCLUSION Cognitive load and short glances away from the road are additive in their tendency to increase the likelihood of drivers missing safety-critical events. APPLICATION This study demonstrates the need to consider the combined consequence of cognitive load and brief glances away from the road in the design of emerging in-vehicle devices and the need to provide drivers with better feedback regarding these consequences.