Abstract
Do physically salient stimuli—such as color singletons—have an automatic power to capture attention? This question has spurred a longstanding debate, but recent evidence has supported a hybrid model called the signal suppression hypothesis. According to this account, salient distractors automatically attract attention, but can be proactively suppressed via top-down control processes to prevent attentional capture. Importantly, many of the previous studies supporting this account have used singleton distractors with relatively low salience. That is, most studies indicating suppression of salient stimuli have used color singletons at relatively low set sizes (4 or 6 items). The current study adapted the capture-probe paradigm to assess capture by highly salient color singletons at exceptionally large set sizes (10 or 30 items). In three experiments, we observed no evidence that highly salient color singletons captured attention and instead found they were suppressed. Importantly, we did find clear evidence that suppression effects can sometimes be masked by floor effects in overall probe performance. We introduce a new methodology to remedy this problem: limiting the number of items that are simultaneously probed. Altogether, the results support the signal suppression hypothesis and refute bottom-up accounts of attentional capture.