Abstract
Attention has consistently been shown to be biased toward threatening objects in experimental settings, leading to distraction in a goal-directed attention task. In real-world environments, automobile drivers perceive close encounters with bicyclists as threatening, permitting an examination of the implications of threat-related attentional biases with respect to real-world behavior. Here, we examined whether participants in a high-fidelity driving simulator perceived encounters with bicyclists as threatening and how this modulated driving behavior. Participants (n = 101) with a valid driver’s license and at least 1.5 years of driving experience completed two simulated drives, one with a 40 miles-per-hour (mph) posted speed limit and another with a 25 mph posted speed limit. Each drive consisted of four interactions with a bicyclist. For the first interaction, participants encountered a bicyclist riding inside the lane in front of their vehicle and were forced to decide when to overtake the bicyclist or to continue trailing behind the bicyclist. The other three interactions included a right turn, a left turn, and a stop at a 4-way intersection in which the participant and a bicyclist arrived at the intersection at approximately the same time, requiring the participant to decide whether to yield to the bicyclist. We hypothesized that bicyclists would evoke a robust threat and orienting response, the strength of which would be associated with safer driving behavior. The results revealed increased physiological responses of heart rate and electrodermal activity when the bicyclist is in the driver’s field of view. In addition, drivers made increased eye movements toward the bicyclist, which were collectively associated with safer driving (measured from distance between driver and bicyclist, decisions whether and when to pass a bicyclist, and consistency of lane position during bicyclist interaction). Our findings offer a real-world demonstration of how threat-related attentional biases can be adaptive.