Article
Improvement of sound localization after spatially congruent audiovisual exposure: A special case of crossmodal recalibration or higher-order visual location learning? (en)
* Presenting author
Abstract:
Auditory spatial representations are constantly recalibrated by visual input. A prominent example is the ventriloquism aftereffect (VAE), in which brief passive exposure to audiovisual stimuli with a consistent spatial disparity causes a corresponding shift in subsequent auditory localization. Similarly, exposure to spatially congruent audiovisual stimuli has been found to elicit multisensory enhancement (ME) in subsequent sound localization performance. Recent research has indicated that these two effects might involve partially distinct neural mechanisms. Nevertheless, both VAE and ME have been thought to critically depend on multisensory integration of the audiovisual stimuli during the exposure phase. However, prior studies have not tested the possibility that participants might simply acquire knowledge about the locations of sound sources from the visual stimulus positions alone, independently of multisensory integration. To test this alternative account, we conducted an experiment in which participants localized sounds before and after exposure to unimodal visual stimuli presented at the same locations as the sound sources used in the pre- and posttest. No significant reduction of auditory localization errors was found after unimodal visual exposure, suggesting that higher-order visual location learning cannot adequately explain the ME. Instead, our findings support the notion that ME represents a unique instance of crossmodal recalibration.