Multisensory enhancement of attentional capture in visual search.

Multisensory integration increases the salience of sensory events and, therefore, possibly also their ability to capture attention in visual search. This was investigated in two experiments where spatially uninformative color change cues preceded visual search arrays with color-defined targets. Tones were presented synchronously with these cues on half of all trials. Spatial-cuing effects indicative of cue-triggered capture of attention were larger on tone-present than on tone-absent trials, demonstrating multisensory enhancements of attentional capture. Larger capture effects for audiovisual events were found when cues were color singletons, and also when they appeared among heterogeneous color distractors. Tone-induced increases of attentional capture were independent of color-specific top-down task sets, suggesting that this multisensory effect is a stimulus-driven bottom-up phenomenon.