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Norimichi Kitagawa

Publications and source records attributed to Norimichi Kitagawa.

2 recordsLinked to original sources

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.

Acoustic Stimulation↗

Hearing visual motion in depth.

Auditory spatial perception is strongly affected by visual cues. For example, if auditory and visual stimuli are presented synchronously but from different positions, the auditory event is mislocated towards the locus of the visual stimulus-the ventriloquism effect. This 'visual capture' also occurs in motion perception in which a static auditory stimulus appears to move with the visual moving object. We investigated how the human perceptual system coordinates complementary inputs from auditory and visual senses. Here we show that an auditory aftereffect occurs from adaptation to visual motion in depth. After a few minutes of viewing a square moving in depth, a steady sound was perceived as changing loudness in the opposite direction. Adaptation to a combination of auditory and visual stimuli changing in a compatible direction increased the aftereffect and the effect of visual adaptation almost disappeared when the directions were opposite. On the other hand, listening to a sound changing in intensity did not affect the visual changing-size aftereffect. The results provide psychophysical evidence that, for processing of motion in depth, the auditory system responds to both auditory changing intensity and visual motion in depth.

Acoustic Stimulation↗