Kugler Günter, 't Hart Bernard Marius, Kohlbecher Stefan, Einhäuser Wolfgang, Schneider Erich
Institute of Clinical Neurosciences, University of Munich, Munich, Germany.
German Center for Vertigo and Balance Disorders, University of Munich, Munich, Germany.
PLoS One. 2015 Dec 30;10(12):e0145910. doi: 10.1371/journal.pone.0145910. eCollection 2015.
Visual search can be accelerated when properties of the target are known. Such knowledge allows the searcher to direct attention to items sharing these properties. Recent work indicates that information about properties of non-targets (i.e., negative cues) can also guide search. In the present study, we examine whether negative cues lead to different search behavior compared to positive cues. We asked observers to search for a target defined by a certain shape singleton (broken line among solid lines). Each line was embedded in a colored disk. In "positive cue" blocks, participants were informed about possible colors of the target item. In "negative cue" blocks, the participants were informed about colors that could not contain the target. Search displays were designed such that with both the positive and negative cues, the same number of items could potentially contain the broken line ("relevant items"). Thus, both cues were equally informative. We measured response times and eye movements. Participants exhibited longer response times when provided with negative cues compared to positive cues. Although negative cues did guide the eyes to relevant items, there were marked differences in eye movements. Negative cues resulted in smaller proportions of fixations on relevant items, longer duration of fixations and in higher rates of fixations per item as compared to positive cues. The effectiveness of both cue types, as measured by fixations on relevant items, increased over the course of each search. In sum, a negative color cue can guide attention to relevant items, but it is less efficient than a positive cue of the same informational value.
当目标的属性已知时，视觉搜索可以加快。这种知识使搜索者能够将注意力指向具有这些属性的项目。最近的研究表明，关于非目标属性的信息（即负面线索）也可以引导搜索。在本研究中，我们检验与正面线索相比，负面线索是否会导致不同的搜索行为。我们要求观察者搜索由特定形状的单独元素（实线中的虚线）定义的目标。每条线都嵌入在一个彩色圆盘中。在“正面线索”组中，参与者被告知目标项目可能的颜色。在“负面线索”组中，参与者被告知不可能包含目标的颜色。搜索显示的设计使得在正面和负面线索条件下，可能包含虚线（“相关项目”）的项目数量相同。因此，两种线索的信息量是相等的。我们测量了反应时间和眼动。与正面线索相比，参与者在收到负面线索时表现出更长的反应时间。虽然负面线索确实将眼睛引导到了相关项目上，但眼动存在明显差异。与正面线索相比，负面线索导致对相关项目的注视比例更小、注视持续时间更长且每个项目的注视率更高。通过对相关项目的注视来衡量，两种线索类型的有效性在每次搜索过程中都有所提高。总之，负面颜色线索可以将注意力引导到相关项目上，但它的效率低于具有相同信息价值的正面线索。
