Abstract
People process visual information more efficiently when visual experience provides regularities even when these regularities are processed by the brain in the absence of awareness (i.e., implicit memory). However, theories of attentional control propose that visual attention is only guided by a special explicit memory representation held in visual working memory. Here we had human observers perform a visual search task for a set of target shapes. We varied the percentage of target shapes that happened to appear in each color, despite the color being task irrelevant. Our results show that observers found the target shapes faster when they appeared in the colors with the higher target probability associations. This effect emerged within the first block of trials, and appears to be dissociable from priming of pop-out. Debriefing questionnaires revealed no explicit use of the color as a cue to target identity. Altogether, these results suggest that implicit memory for previously searched for targets may be constantly guiding attention, taking advantage of the unlimited unconscious resource to guide attention instead of relying on the limited-capacity conscious processes.