Abstract
In a color-oddball search task, when a target's color in the current search display has been passively viewed in a preceding target-absent display, the response time (RT) to the target is slower than when, instead, the distractor's color in the current search display was passively viewed. This phenomenon is known as distractor previewing effect (DPE). Goolsby et al. (2005) proposed that the color of items in target-absent displays is perceptually suppressed in the subsequent target-present display. Lleras et al. (submitted), however, proposed that the DPE reflects inhibition of focused attention to items containing the target-absent feature in the previous display. We tested these two hypotheses using event-related brain potentials (ERPs). Sixteen young adults were presented with target-absent displays, comprising four identically colored items (one per quadrant), followed by target-present displays, containing one color-oddball item. Participants made a choice response based on the shape (triangle/circle) of the color-oddball in the search display. We found: (1) faster RT and higher accuracy in the distractor-color preview (DCP) than in the target-color preview (TCP) condition; (2) an earlier peak and larger N2pc component in the DCP than in the TCP at posterior recording locations with a latency of 200–400 ms after the search display onset; (3) no differences in early sensory ERP effects (e.g., N1 or P1) between the DCP and TCP conditions. These results support the idea that the DPE is driven by inhibition of focused attention to a failed feature rather than by perceptual suppression of a previewed feature.