Intertrial priming of popout search on visual prior entry

When the features of a visual target and of nontargets are repeated between successive search displays, responding to a subsequent target is faster than when the features of the target and the nontargets switch between trials. This intertrial priming effect can influence perceptual processes, postperceptual processes (e.g., episodic retrieval), or both. Previous studies have shown that repeating irrelevant visual features that do not define the target or the response can influence postperceptual processes. The present study examined whether intertrial priming by irrelevant features also influences perceptual processes. Subjects completed a temporal order judgment task that appeared within a popout visual search display containing a color singleton among nonsingletons, all of which served as placeholders for two probes. Intertrial priming by the placeholder colors shifted the psychometric function. Specifically, the probes appearing at the color singleton in the switch condition needed to appear earlier than the probes at the color singleton in the repeat condition to be perceived simultaneous with the probes on a nonsingleton. This suggests there was an influence of intertrial priming by the irrelevant colors on visual prior entry; hence, repeating irrelevant features between trials can influence perpetual processes.