Distortion of auditory space during visually induced self-acceleration

Abstract

Perception of self-motion is based on integration of multiple sensory inputs, especially from the vestibular and visual systems. Our previous study demonstrated that vestibular information on linear acceleration distorted auditory space perception (Teramoto et al., 2012, PLoS ONE, 7(6), e39402). However, it is unclear whether this phenomenon is contingent on vestibular signals or can be caused by inputs from the other sensory modalities involving self-motion perception. Here, we investigated whether visual information on linear self-acceleration can also alter auditory space perception. Large-field visual motion which simulated either forward or backward self-motion was presented on a screen without vestibular information. During the visual motion stimulation, a short noise burst was delivered from one of loudspeakers that were aligned parallel to the simulated self-motion direction along a wall to the left of participants. The participants indicated in which direction the noise burst was presented, forward or backward relative to their subjective coronal plane. The noise burst was delivered after participants reported self-motion (Experiment 1) or irrespective of the participants’ experience of self-motion (Experiment 2). Results showed that the sound position aligned with the subjective coronal plane was displaced in the traveling direction for self-acceleration conditions only when the sound was delivered after the participants reported self-motion perception. These results suggest that self-motion information, irrespective of its origin, is crucial for this distortion of auditory space perception.