Evidence for a system in the auditory periphery that may contribute to linking sounds and images in space

Abstract

Eye movements alter the relationship between the visual and auditory spatial scenes. Signals related to eye movements affect the brains auditory pathways from the ear through auditory cortex and beyond, but how these signals might contribute to computing the locations of sounds with respect to the visual scene is poorly understood. Here, we evaluated the information contained in the signals observed at the earliest processing stage, eye movement-related eardrum oscillations (EMREOs). We report that human EMREOs carry information about both horizontal and vertical eye displacement as well as initial/final eye position. We conclude that all of the information necessary to contribute to a suitable coordinate transformation of auditory spatial cues into a common reference frame with visual information is present in this signal. We hypothesize that the underlying mechanism causing EMREOs could impose a transfer function on any incoming sound signal, which could permit subsequent processing stages to compute the positions of sounds in relation to the visual scene.