A dual-stage account of inter-trial priming effects.

The study of inter-trial effects in visual search has generated an increasing amount of research in recent years. However, the mechanisms underlying these effects are still a matter of debate. Two rival accounts have been suggested. One view stipulates that inter-trial effects facilitate early perceptual/attentional processes, whereas the other proposes that it affects post-perceptual response-related processes. Here, we focused on the priming of pop-out effect (PoP, Maljkovic & Nakayama, 1994), which refers to the well-established finding that performance on singleton search is faster when the target and distractors features repeat on two consecutive trials than when they switch. We set out to resolve the current controversy surrounding PoP by suggesting a dual-stage account, according to which PoP speeds both an early perceptual stage and a later, response-related stage of visual search. We were able to dissociate the hypothesized components of PoP by tracking their time course. Copyright 2010 Elsevier Ltd. All rights reserved.