The impact of attentional set and situation awareness on dual tasking driving performance

•Dual taskers use enduring attentional sets when resources are shared between tasks.•Reliance on attentional set contributes to decreased detection of unexpected events.•Distraction leads to longer reaction times for unexpected events. The impact of attentional set and situation awareness on event detection and reaction times was investigated in 2 simulated driving experiments. Experiment 1: thirty participants viewed and reacted to thirty driving films containing unexpected items which were either driving congruent or incongruent. Group 1 completed the task without distraction; group 2 completed a concurrent conversation task. Experiment 2: thirty participants viewed and reacted to twenty driving films which contained unexpected yet driving relevant events. Half of the participants completed the task without distraction and half completed a concurrent conversation task. Measures of event detection and reaction time were recorded for both experiments. Compared to undistracted participants, dual-taskers reacted to fewer unexpected events; recorded longer reaction times; and reacted to fewer incongruent and peripheral events, suggesting an enduring attentional set for driving. Dual tasking drivers may adopt a strategy of over-reliance on schema-driven processing when attention is shared between tasks.