Oculomotor capture by colour singletons depends on intertrial priming

In visual search, an irrelevant colour singleton captures attention when the colour of the distractor changes across trials (e.g., from red to green), but not when the colour remains constant (Becker, 2007). The present study shows that intertrial changes of the distractor colour also modulate oculomotor capture: an irrelevant colour singleton distractor was only selected more frequently than the inconspicuous nontargets (1) when its features had switched (compared to the previous trial), or (2) when the distractor had been presented at the same position as the target on the previous trial. These results throw doubt on the notion that colour distractors capture attention and the eyes because of their high feature contrast, which is available at an earlier point in time than information about specific feature values. Instead, attention and eye movements are apparently controlled by a system that operates on feature-specific information, and gauges the informativity of nominally irrelevant features.

Research highlights
► Previously, it was believed that the ability of irrelevant objects to capture our attention and eyes depends on their feature contrast (saliency).
► Here, it is shown that involuntary capture depends more on the constancy of feature values assigned to the target and distractor.
► Specifically, an irrelevant distractor captures the eyes only when it inherits the features formerly associated with the target of search.
► This demonstrates that capture is not so much determined by saliency but rather by feature-specific carry-over effects.