Color singletons are suppressed under serial search, but not abrupt onsets.

In the fields of cognitive psychology, two types of stimuli are well known to powerfully capture one's attention: salient, singleton stimuli standing out from its surroundings and abruptly appearing stimuli. The present study compared how these two kinds of attention-capturing stimuli affect visual search tasks. Specifically, we investigated whether the effects of singleton stimuli and abrupt onsets would differ, depending on how visual searches proceed. As a result, significant attentional capture by a singleton stimulus was found when multiple stimuli were processed in parallel within a large attentional window. However, when the degree of serial processing increased, the singleton stimulus was suppressed. By contrast, abrupt onsets consistently captured attention, regardless of how searches proceed. The present study demonstrates distinct mechanisms mediating attentional capture by salient singletons and abrupt onsets and pinpoints the importance of attentional window and search modes on attentional capture.