Reproducing Reality: Multimodal Contributions in Natural Scene Discrimination

Most research on multisensory processing focuses on impoverished stimuli and simple tasks. In consequence, very little is known about the sensory contributions in the perception of real environments. Here, we presented 23 participants with paired comparison tasks, where natural scenes were discriminated in three perceptually meaningful attributes: movement, openness, and noisiness. The goal was to assess the auditory and visual modality contributions in scene discrimination with short (≤500ms) natural scene exposures. The scenes were reproduced in an immersive audiovisual environment with 3D sound and surrounding visuals. Movement and openness were found to be mainly visual attributes with some input from auditory information. In some scenes, the auditory system was able to derive information about movement and openness that was comparable with audiovisual condition already after 500ms stimulation. Noisiness was mainly auditory, but visual information was found to have a facilitatory role in a few scenes. The sensory weights were highly imbalanced in favor of the stronger modality, but the weaker modality was able to affect the bimodal estimate in some scenes.