Abstract
Priming in pop-out search reduces reaction time when the target’s feature is repeated in successive trials (Maljkovic & Nakayama, VR 1994). The level at which this effect occurs has been a long-standing debate (e.g., Kristjánsson, VR 2006; Huang et al., M&C 2004). In the double-drift stimulus, a target patch moves in one direction while its internal 1/f noise drifts in the orthogonal direction, causing the perceived path to deviate dramatically from the physical path. Previous studies showed that the perceived and physical paths are represented at different stages of the visual hierarchy (Liu et al., 2020); moreover, pop-out is seen for a perceived oddball in the presence of conflicting physical paths, but not for a physical oddball in the presence of conflicting perceived paths (Özkan et al., AP&P, 2020). Thus, double-drift trajectories provide a critical test for the level of processing and the mechanism underlying priming in visual search by examining whether repeated physical and/or perceived paths induced priming. In each trial, we presented two arrays of 8 moving patches, separated by 200 ms. Each array included a target that is both a perceived and a physical oddball. The oddballs in the first and the second arrays could either share perceived or physical directions or both or none. Each item had a red or green dot superimposed on its center. Participants reported the color of the target's dot (50% probability). Repetition of a perceived pop-out feature produced significant priming that transferred to all locations. Repetition of a physical pop-out feature also produced significant priming, although of a lesser magnitude, but, importantly, only to positions within the same hemifield (left vs right). Our findings suggest that priming occurs in multiple stages of the visual hierarchy while the spatially global effects arise only for late representations.