Audio-visual peripheral localization disparity
Last modified: 2011-09-02
Abstract
In localizing simultaneous auditory and visual events, the brain should map the audiovisual events onto a unified perceptual space in a subsequent spatial process for integrating and/or comparing multisensory information. However, there is little qualitative and quantitative psychological data for estimating multisensory localization in peripheral visual fields. We measured the relative perceptual direction of a sound to a flash when they were simultaneously presented in peripheral visual fields. The results demonstrated that the sound and flash were perceptually located at the same position when the sound was presented in 5°-periphery from the flash. This phenomenon occurred, even excluding the trial in which the participants’ eyes moved. The measurement of the location of each sound and flash in a pointing task showed that the perceptual location of the sound shifted toward the frontal direction and conversely the perceptual location of the flash shifted toward the periphery. Our findings suggest that unisensory perceptual spaces of audition and vision have deviations in peripheral visual fields and when the brain remaps unisensory locations of auditory and visual events into unified perceptual space, the unisensory spatial information of the events can be suitably maintained.