A size singleton matching the target-distractor size relation cannot capture attention when it appears outside of attentional window

摘要

Recent studies have shown that an irrelevant size-singleton cue that matches target-distractor size relation captures attention, resulting in faster RT and a large N2pc to the target at that cued location. By using the spatial blink paradigm, the present study examined whether a peripheral size-singleton distractor that matches the target-distractor size relation can capture visual attention and disrupt central target identification. Three experiments consistently showed that a size singleton that matches a target-distractor size relation cannot capture attention when it appears outside of the attentional window. However, the same size singleton still produces a cuing effect. In addition, a color singleton that matches target color, instead of a size singleton that matches a target-distractor size relation, captures attention when it is outside of the attentional window. In conclusion, a size-relation-matched distractor is much weaker than a color-matched distractor in capturing visual attention and cannot capture attention when the distractor appears outside of the attentional window. Moreover, these results also suggest that a classical Cuing task might not be a sufficient test of contingent capture in the spatial domain. In a classical cuing task, there is no stringent spatial control because the target can appear at any location. In addition, N2pc can be induced by not only involuntary capture but also by voluntary selection of target. Thus a cuing effect along with N2pc is necessary yet insufficient to confirm the presence of contingent capture.