Onset of background dynamic noise attenuates preview benefit in inefficient visual search.

When certain distractors (old items) appear before others (new items) during an inefficient visual search task, observers exclude the old items from the search (preview benefit), possibly because their locations are deprioritized relative to the locations of the new items. We examined whether participants were able to ignore task-irrelevant changes in a scene (i.e., the onset of repetitive changes, continual repetitive changes, and the cessation of repetitive changes in the background), while performing a preview search task. The results indicated that, when the noise continually changed position throughout each trial, or when dynamic noise was changed to static noise simultaneous with the appearance of the search display, the preview benefit remained. In contrast, when the static background noise was changed to dynamic background noise, simultaneous with the appearance of the search display, this task-irrelevant background event abolished the preview benefit on search efficiency. Therefore, we conclude that the onset of task-irrelevant repetitive changes in the background disrupts the process of inhibitory marking of old items.