Orientation search is mediated by distractor suppression: evidence from priming of pop-out

In search for a singleton target, performance is considerably improved when the target and distractors repeat than when they switch roles, an effect called priming of pop-out or PoP (Maljkovic & Nakayama, 1994). Although this phenomenon has been replicated across a variety of dimensions, orientation PoP has proved to be volatile. Recent research has shown that target activation and distractor inhibition mechanisms underlie PoP (Lamy, Antebi, et al., 2008). Relying on this finding, we show that unlike in color and shape search, only distractor inhibition processes contribute to PoP in orientation search, which resolves the apparent inconstancies in the literature. The implications of this finding for mechanisms underlying PoP and orientation singleton search are discussed.