Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD, 21218, USA.
Atten Percept Psychophys. 2021 Jan;83(1):260-269. doi: 10.3758/s13414-020-02207-8. Epub 2020 Nov 25.
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.
虽然人们通常认为，即使一个物理上显著的刺激与当前任务无关，它也会自动吸引注意力，但信号抑制假说提出，观察者可以主动抑制显著但不相关的干扰物。然而，目前尚不清楚仅仅抑制（即没有目标增强）是否足以克服在同质背景下显著的单一刺激对注意力的捕获。本研究解决了这个问题。在搜索试验（70%的试验）中，参与者在包含或不包含不相关颜色单一刺激的试验中搜索形状目标。在穿插的探测试验（30%的试验）中，检查了学习抑制单一刺激颜色的效果。在这些试验中，参与者搜索一个探测目标字母；这些字母出现在四个椭圆形上（一个彩色椭圆形和三个灰色椭圆形）。每个彩色椭圆形都是一种单一刺激，有三种类型：搜索试验中干扰物的颜色、搜索试验中目标的颜色或在搜索试验中未出现的中性颜色。与灰色椭圆形相比，探测目标在中性或目标颜色的项目上的反应更快；然而，与灰色椭圆形相比，探测目标在干扰物颜色的项目上的反应更慢。结果表明，一种强大的抑制机制可以克服单一刺激项目对注意力的捕获。
