Salience effects on attentional selection are enabled by task relevance

Attention is a limited resource that must be carefully controlled to prevent distraction. Much research has demonstrated that distraction can be prevented by proactively suppressing salient stimuli to prevent them from capturing attention. It has been suggested, however, that prior studies showing evidence of suppression may have used stimuli that were not truly salient. This claim has been difficult to test because there are currently no agreed-upon methods to demonstrate that an object is salient. The current study aims to help resolve this by introducing a new technique to test the role of salience in attentional capture. Low- and high-salience singletons were generated via a manipulation of color contrast. An initial experiment then verified the manipulation of salience using a search task where the color singleton was the target and could only be found via its bottom-up popout. High-salience singletons were found much more easily than low-salience singletons, suggesting that salience powerfully influenced attention when task relevant. A following experiment then used the same stimulus displays but adapted the task so that the singletons were task-irrelevant distractors. Both low- and high-salience singletons were suppressed, suggesting neither was able to capture attention. These results challenge purely stimulus-driven accounts by showing that improving salience only enhances attentional allocation in situations where the object is also task relevant. The results are instead consistent with the signal suppression hypothesis, which predicts that task-irrelevant singletons can be suppressed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).