Inhibitory tagging in an interrupted visual search.

Inhibition of return facilitates visual search, biasing attention away from previously examined locations. Prior research has shown that, as a result of inhibitory tags associated with rejected distractor items, observers are slower to detect small probes presented at these tagged locations than they are to detect probes presented at locations that were unoccupied during visual search, but only when the search stimuli remain visible during the probe-detection task. Using an interrupted visual search task, in which search displays alternated with blank displays, we found that inhibitory tagging occurred in the absence of the search array when probes were presented during these blank displays. Furthermore, by manipulating participants' attentional set, we showed that these inhibitory tags were associated only with items that the participants actively searched. Finally, by probing before the search was completed, we also showed that, early in search, processing at distractor locations was actually facilitated, and only as the search progressed did evidence for inhibitory tagging arise at those locations. These results suggest that the context of a visual search determines the presence or absence of inhibitory tagging, as well as demonstrating for the first time the temporal dynamics of location prioritization while search is ongoing.