Abstract
Humans perceive outer environments by integrating information from multiple senses. Auditory information often alters visual perception, and many audio-visual interactions have been reported. For example, auditory stimuli alter the motion trajectory from "stream" to "bounce," or changing pitch induces the visual motion illusion. However, these studies utilized compound visual stimuli producing ambiguous perceptions relatively easily. Therefore, we examined whether changing pitch could alter the motion trajectory using simple apparent motion stimuli. The results indicated that downward trajectory was perceived dominantly when descending pitch tone was presented simultaneously. When ascending pitch tone was presented, on the other hand, upward trajectory tended to perceive, while this effect small not significant.
