Negative cues lead to more inefficient search than positive cues even at later stages of visual search.

Observers can focus their attention on task-relevant items in visual search when they have prior knowledge about the target's properties (i.e., positive cues). However, little is known about how negative cues, which specify the features of task-irrelevant items, can be used to guide attention away from distractors and how their effects differ from those of positive cues. It has been proposed that when a distractor color is cued, people would first select the to-be-ignored items early in search and then inhibit them later. The present study investigated how the effects of positive and negative cues differ throughout the visual search process. The results showed that positive cues sped up the early stage of visual search and that negative cues led to initial selection for inhibition. We further found that visual search with negative cues was more inefficient than that with positive cues even at later stages, suggesting that sustained inhibition is needed throughout the visual search process. Taken together, the results indicate that positive and negative cues have different functions: prior knowledge about target features can weight task-relevant information at early stages of visual search, and negative cues are used more inefficiently even at later stages of visual search.