Audio-visual integration in temporal perception.

In situations of audio-visual interaction, research has generally found that audition prevails over vision in temporal perception, while vision is dominant over audition for spatial perception. Modality appropriateness to a given task generally determines the direction of this inter-modality effect. However, we found a reverse effect in some situations where a change in the frequency of visual stimuli was associated with a perceived change in the frequency of auditory stimuli. In our experiment, 12 participants were asked to judge the change in the frequency of visual and auditory stimuli using a visual flicker and auditory flutter stimuli. In some conditions either the auditory or the visual information was ambiguous. In addition to confirming the expected finding that a change in the frequency of the auditory stimuli induced a perceived change in the frequency of the visual stimuli, we found a new phenomenon. When ambiguous auditory temporal cues were presented, the change in the frequency of the visual stimuli was associated with a perceived change in the frequency of the auditory stimuli. This suggests that cross-modal asymmetry effects are influenced by the reliability of visual and auditory information as well as modality appropriateness.