The pattern of shading across an image can provide a rich sense of object shape. Our ability to use shading information is remarkable given the infinite possible combinations of illumination, shape and reflectance that could have produced any given image. Illumination can change dramatically across environments (e.g. indoor vs. outdoor) and times…

Maljkovic and Nakayama have demonstrated memory influences in singleton search from one trial to the next, an effect they termed "priming of pop-out" (PoP). This effect was described as resulting from the persistence of an implicit memory trace, the influence of which could be observed for around 5-8 subsequent trials. Thomson and…

Three experiments examined memory-based guidance of visual search using a modified version of the contextual-cueing paradigm (Jiang & Chun, 2001). The target, if present, was a conjunction of color and orientation, with target (and distractor) features randomly varying across trials (multiconjunction search). Under these conditions, reaction times…

People categorized pairs of perceptual stimuli that varied in both category membership and pairwise similarity. Experiments 1 and 2 showed categorization of 1 color of a pair to be reliably contrasted from that of the other. This similarity-based contrast effect occurred only when the context stimulus was relevant for the categorization of the…