Content Matters: Visual (Alert) Messages as Primes for Guiding Driver Attention in a Visual Search Task

To travel safely, drivers must attend to various elements in their driving environment. When visually scanning for these elements, attention can be guided by a prime that provides target information. In a vehicle, this prime could be shown as a visual (alert) message to alert the driver in various situations. In an online experiment (N = 72), four primes (text warning, symbol warning, scene picture, target picture) were used in a visual search for five targets (pedestrian, cyclist, car, traffic sign, roadway). Reaction time until finding the target was measured via a button press. All primes led to a decrease in search time compared to the control condition. The text warning and scene picture did not differ significantly and were the least effective in improving reaction time. The symbol warning was the next more effective prime. Finally, the target picture resulted in the quickest visual search. The effectiveness of a prime depends on its characteristics. To reduce cognitive processing time, the prime should be visual rather than semantic (i.e., text). Also, it should share as many visual features with the target as possible to provide optimal attentional guidance.