Positional priming of pop-out: A relational-encoding account

Three experiments examined whether positional priming of pop-out is modulated by target salience. In Experiment 1, the singleton target appeared among variable numbers of distractors (2, 3, 5, 7; blocked presentation). While facilitation of target locations was not influenced by distractor number, inhibition of distractor locations was evident only with two distractors in the display. In Experiment 2, 3- and 6-item displays, with 2 and 5 distractors, respectively, were intermixed rather than blocked. It was found that, when the majority (but not the minority) of trials contained 3-item displays, there was carryover of distractor location inhibition from 3- to 6-item displays (but not vice versa). In Experiment 3 (1 target, 2 distractors), inhibitory priming of distractor locations could even be evoked when the current target was presented at an empty but merely expected distractor location in the previous trial. These findings argue that target salience is not an adequate account of positional priming. Instead they suggest that the relational encoding of the regular (triangle) stimulus arrangement contributes to positional priming.