Probability cueing of singleton-distractor regions in visual search: the locus of spatial distractor suppression is determined by colour swapping

Abstract

ABSTRACTObservers can learn the likely locations of salient distractors in visual search, reducing their potential to cause interference. While there is agreement that this involves suppression of frequent distractor locations, the results are mixed regarding the stage of suppression: the search-guiding priority map or, respectively, the distractor-defining dimension. Critical for deciding this question is whether or not a distractor-position effect (reduced interference by distractors at frequent locations) is accompanied by a target-position effect (slowed response times to targets at frequent locations) when the distractor is defined in a different dimension to the target: priority-map based suppression would impact target as well as distractor signals; distractor-dimension-based suppression only distractor signals. To identify the factors that are critical for observing one or the other effect pattern, the present study adopted a paradigm in which the distractor was likely to appear in a larger region of the display and orthogonally varied display density (singleton saliency) and random swapping of the distractor and non-distractor colours. Both effect patterns were found consistently, with the critical factor being colour swapping/consistency: with swapping colours, observers tend to adopt a priority-map-based suppression strategy; with consistent colours, a dimension-based strategy.