Variations in the magnitude of attentional capture: testing a two-process model.

Although large variations in the magnitude of attentional capture have been evidenced across a wide range of studies and paradigms (see Burnham, 2007, for a review), the nature of these variations is unclear. In the present study, we used a modified spatial cuing task to address two related issues. In the first experiment, we explored the hypothesis that the magnitude of attentional capture varies systematically as a function of cue-target similarity. Targets of a particular color were preceded by uninformative peripheral cues carrying varying percentages of the target color. As was predicted, the magnitude of attentional capture varied directly with the similarity between cue and target. In the second experiment, we explored whether these similarity effects reflect a mixture of trials on which attention is fully captured and trials on which attention is not captured at all (i.e., a two-process model). A mixture analysis conducted on obtained reaction time distributions proved inconsistent with a two-process model.