Distractor size matters: Distractors may, or may not, speed target-absent searches

Years of research have dissected the effects of salient distractors on visual search efficiency, typically finding that distractors slow visual search and increase error rates when detecting targets. Nonetheless, Moher (2020) recently demonstrated that the effects of salient distractors on visual search depend on target presence/absence. Specifically, when targets were present, Moher found that distractors slowed search speeds and increased error rates. However, when targets were absent, search speeds decreased, suggesting a strategy change in observers that lowered the quitting thresholds for target-absent visual search. This counterintuitive finding appears to depend on the salience of the distractor. Replicating Moher (2020), we found that when the distractor was much larger than the other items, search speeds for target-absent trials were faster compared to when there was no distractor. In contrast, when a smaller but still salient distractor was used, search speeds for target-absent trials were slower compared to when the distractor was absent. Note that in both experiments the distractor was a different color than the other items. Potential reasons for these qualitatively divergent findings include the distance between the salient distractor and other search items or a shift in search strategy, which only emerges with very high salience distractors.