Abrupt onsets cannot be ignored.

Participants identified target letters at cued locations in the presence of occasional abrupt onsets of new distractor letters. The onsets distracted the participants and impaired their letter identification performance despite confirmation that they were using the information provided by the cue. This result contrasts with earlier results found by other researchers that revealed an ability of participants to ignore abrupt onsets in some cases. Our results, however, were obtained under conditions that prevented anticipatory eye movements to the target. In a subsequent experiment when participants were permitted to look at the target in advance, the distracting effect of the onsets was eliminated, suggesting that participants may have looked at the target in the earlier studies. We conclude that abrupt onsets cannot be ignored unless the target element receives a substantial advantage via fixation.