Although it is often assumed that a physically salient stimulus automatically captures attention even when it is irrelevant to a current task, the signal-suppression hypothesis proposes that observers can actively suppress a salient-but-irrelevant distractor. However, it is still unknown whether suppression alone (i.e., without target enhancement) is potent enough to override attentional capture by a salient singleton in an otherwise-homogeneous background. The current study addressed this issue. On search trials (70% of trials), participants searched for a shape target on trials that either did or did not contain an irrelevant color singleton. The effects of learning to suppress the color of the singleton were examined on interleaved probe trials (30% of trials). On these trials, participants searched for a probe target letter; those letters were presented on four ovals (one colored oval and three gray ovals). Each colored oval was a singleton that was one of three types: the color of the distractor on search trials, the color of the target on search trials, or a neutral color that had not appeared on search trials. Responses were faster for the probe target on a neutral-colored or target-colored item than on a gray-colored item; however, responses were slower for the probe target on a distractor-colored item than on a gray-colored item. The results demonstrate a powerful suppression mechanism overriding attentional capture by a singleton item.

尽管通常认为即使与当前任务无关时，物理上的显着刺激也会自动引起注意，但信号抑制假设提出，观察者可以主动抑制显着但无关的干扰物。然而，仍然未知的是，单独的抑制（即没有目标增强）是否足以有效地克服同质背景中显着的单例的注意力捕获。当前的研究解决了这个问题。在搜索试验中（占试验的70％），参与者在包含或不包含无关颜色单例的试验中搜索形状目标。在交错探针试验中（30％的试验）检查了学习抑制单例颜色的效果。在这些试验中，参与者搜索了一个探测目标字母。这些字母出现在四个椭圆形（一个彩色的椭圆形和三个灰色的椭圆形）上。每个彩色的椭圆都是一个单例，是以下三种类型之一：搜索试验中的干扰物颜色，搜索试验中目标物的颜色或搜索试验中未出现的中性色。对于中性色或目标色项目，探测目标的响应要快于对灰色目标的响应。但是，对于干扰目标颜色的项目，探测目标的响应要慢于对灰色目标的响应。结果表明，强大的抑制机制可以克服单项引起的注意力捕获。或搜索试验中未出现的中性色。对于中性色或目标色项目，探测目标的响应要快于对灰色目标的响应。但是，对于干扰目标颜色的项目，探测目标的响应要慢于对灰色目标的响应。结果表明，强大的抑制机制可以克服单项引起的注意力捕获。或搜索试验中未出现的中性色。对于中性色或目标色项目，探测目标的响应要快于对灰色目标的响应。但是，对于干扰目标颜色的项目，探测目标的响应要慢于对灰色目标的响应。结果表明，强大的抑制机制可以克服单项引起的注意力捕获。