Does a salient distractor capture attention early in processing?

Abstract

Kim and Cave (1999) used spatial probes in order to measure the effects of bottom-up and top-down factors on the allocation of spatial attention over time. Subjects searched for a target with a unique shape, with a uniquely colored distractor present on each trial. The singleton distractor captured attention early in processing, whereas attention homed in on the target's location later on. Kim and Cave (1999) concluded that top-down factors cannot prevent the presence of a salient distractor from delaying target selection. The present study tested the idea that such results were obtained only because subjects adopted the strategy of searching for the most salient item. Kim and Cave's (1999) finding was replicated in Experiment 1. In Experiment 2, instead of a feature search, subjects performed a conjunction search-that is, a task that could not be performed using a salience-based strategy. Probe response times were longest at the salient distractor's location at both the short and the long stimulus onset asynchronies. These results suggest that, early in processing, top-down factors can exert their influence and prevent the capture of attention by a salient distractor.