Feature-based attentional set as a cause of traffic accidents

Voluntary and relatively involuntary subsystems of attention often compete. On one hand, people can intentionally "tune" attention for features that then receive visual priority; on the other hand, more reflexive attentional shifts can "short-circuit" top-down control in the face of urgent, behaviourally relevant stimuli. Thus, it is questionable whether voluntary attentional tuning (i.e., attentional set) can affect one's ability to respond to unexpected, urgent information in the real world. We show that the consequences of such tuning extend to a realistic, safety-relevant scenario. Participants drove in a first-person driving simulation where they searched at every intersection for either a yellow or blue arrow indicating which way to turn. At a critical intersection, a yellow or blue motorcycle - either matching or not matching drivers' attentional set-suddenly veered into drivers' paths and stopped in their way. Collision rates with the motorcycle were substantially greater when the motorcycle did not match drivers' attentional sets.