Does the attentional window shed light on the attentional capture debate?

Belopolsky et al. (2007) provided evidence that capture occurs only when objects fall within the attentional window. This attentional window hypothesis was subsequently used to explain how salient stimuli can be powerful yet often have little or no observable effect. In the present study, we attempted to replicate their findings. Participants made a go/no-go decision based on the shape of the overall search array (diffuse attention) or based on the central fixation point (focused attention). Whereas Belopolsky et al. found larger capture effects from a color singleton distractor in the diffuse condition than the focused condition (where the color singleton is assumed to fall outside the attentional window), we found no such effect (Experiment 1). When we changed the task from a feature search task in Experiment 1 to a singleton search task in Experiment 2, capture effects increased overall but were once again similar for the diffuse and focused conditions. This pattern persisted even when we closely replicated Belopolsky et al.'s original design (Experiment 3). Our findings call into question the attentional window account and support an alternative account of why capture sometimes occurs: singleton search mode makes color singletons capture attention because participants are looking for singletons.