The processing locus of interference from salient singleton distractors

Abstract

Numerous studies have demonstrated that target processing is slowed in the presence of an irrelevant singleton element. One hypothesis is that these slowed responses are due to disruptions in the early sensory processing of the targets. We replicated this effect in a resource-limited procedure. However, under data-limited conditions (e.g., brief exposure durations and backward masking), the same singleton distractor did not interfere with performance. Following previous suggestions that data-limited procedures should be sensitive to disruptions in early visual processing (Santee & Egeth, 1982), we conclude that slowed response times in the presence of salient singleton distractors may be due to disruptions in a postperceptual stage of processing such as response selection.

Acknowledgements

We thank Jan Theeuwes, Chris Olivers, and an anonymous reviewer for their helpful suggestions on an earlier version of this work.

Notes

In the present experiments, we adopt a perspective whereby attentional capture may modulate either perceptual or post-perceptual processing. This seems reasonable given that a variety of attention effects can be shown to occur during either stage (e.g., Awh, Vogel, & Oh, 2006).

²In Experiments 2a and 2b, we did not entirely remove the possibility that observers employed a feature search strategy. Observers could still adopt an attentional “set” for a gapped item. However, we note that the size of this gap was very small (0.17°), and therefore, it is unlikely that this strategy was useful to observers.