Sound increases the saliency of visual events

We show that concurrent auditory stimuli can enhance the visual system's ability to detect brief visual events. Participants indicated which of two visual stimuli was briefly blinked off. A spatially non-aligned auditory cue - simultaneous with the blink - significantly enhanced subjects' detection ability, while a visual cue decreased detection ability relative to a no-cue condition. Control experiments indicate that the auditory-driven enhancement was not attributable to a warning effect. Also, the enhancement did not depend on an exact temporal alignment of cue-target onsets or offsets. In combination, our results provide evidence that the sound-induced enhancement is not due to a sharpening of visual temporal responses or apparent prolongation of the visual event. Rather, this enhancement seems to reflect an increase in phenomenal visual saliency. (C) 2008 Elsevier B.V. All rights reserved.