Search for a distressed swimmer in a dynamic, real-world environment.

Visual search is increasingly being explored in dynamic, real-world environments. This includes swimming pools, where lifeguards have shown superior drowning detection in simulated environments. Here, we explored if lifeguard superiority is observed in real-life scenes of a busy swimming pool. Experiment 1 required participants to identify real-life distressed swimmers in clips of busy pool activity via a touchscreen interface. Experiment 2 sought to replicate the first study, with the inclusion of eye-movement measures. Experiment 3 varied the methodology, using an occlusion method where clips were frozen and blurred shortly after target onset. The results demonstrated an experience effect, with lifeguards detecting distressed swimmers more often and faster than nonlifeguards. No clear differences were found in the eye-movements between groups; thus, we cannot conclude that the lifeguards' faster responses are due to better scanning strategies. The different methodological approaches revealed the occlusion method to have the larger effect size, supporting the growing evidence that occlusion may be a better test for dynamic target detection than traditional response-time tests. This research demonstrates that the clear lifeguard experience effect generalizes to real-life pool environments with a large number of swimmers and real incidents. It could be used to inform lifeguard training tools and assessments. (PsycInfo Database Record (c) 2021 APA, all rights reserved).