The Target Prevalence Effect is Mitigated by Less Resource Demanding Stimuli

Although the effect of target prevalence on visual search performance is well documented, the impact of attention use in different search environments on the target prevalence effect is not well understood. Therefore, it is important to better understand what search tasks and environments are appropriate for generalizing the typical target prevalence effect. Low target prevalence typically leads to earlier search termination and increased distractor decisions. This pattern of results could vary due to the amount of attention resources needed or how attention is allocated in different search environments. For example, nature scenes require fewer resources to process and lead to a broader allocation of attention than urban scenes and, therefore, could have a different target prevalence effect than urban scenes. To examine how search environments with different attention use and allocation impact the target prevalence effect, participants detected a rotated nature or urban scene in a rapid serial visual presentation (RSVP) stream of upright scenes from the same category. The rotated scene was either rarely (10%) or often (90%) present. Nature scenes produced fewer misses and a smaller target prevalence effect for the miss rate than urban scenes. This difference could be due to a lower need for attentional resources or a broader allocation of attention for nature scenes. However, on a subset of trials, participants also detected peripheral items, and there was no difference in peripheral item accuracy between nature and urban scenes, suggesting no difference in attention allocation. Therefore, it is more likely that the need for fewer attentional resources to process nature scenes led to better performance and a smaller target prevalence effect. This conclusion supports the idea that visual search environments that require fewer attentional resources lead to a smaller target prevalence effect.