PP1306 - Body Representation Drives Auditory Spatial Perception

Abstract:
Sound localization is the result of computational processes anchored in binaural cues but which also includes the integration of information originating from the different senses. Notably, for the sounds to be localized, they must be perceived in relation to the body, suggesting a strong interaction between the auditory system and the systems mapping the representation of the body in space. Participants performed the Fukuda-Unterberger test while using a sound as a reference in space. The degree of error in localization was significantly larger after the task. This illusory shift confirms the strong connections between sound localization processes and body representation.

Summary:
In this study, we aim to determine if a change in body representation in space has an impact on sound localization. Sound localization is the result of computational processes anchored in binaural cues but which also includes the integration of information originating from the different senses. Notably, for the sounds to be localized, they must be perceived in relation to the body. This suggests strong interactions between the auditory system and the systems mapping the representation of the body in space, which include the somatosensory, vestibular and proprioceptive systems. The influence of auditory cues on postural stability and body orientation has been explored at length. However, the reverse interaction, namely the influence of body representation on sound localization, has never been investigated. Twenty participants with normal auditory and vestibular function were asked to remain still while performing the Fukuda-Unterberger test, known to disrupt the spatial representation of the body in space. Participants performed the task in the presence of a constant auditory signal and were asked to locate the sound before and after performing the task. Before the task, all participants were able to locate the sound source with precision. However, the degree of error in localization (23.67 degrees; SD = 17.60) was significantly larger after the task (t(20)=-4.626; p< .001). This illusory shift confirms the strong connections between sound localization processes and body representation in space, with the latter being shown, for the first time, to affect the former.