An Initial Evaluation of a Direct Vestibular Display in a Virtual Environment

Abstract

The US Air Force Armstrong Laboratory's Human Interface Technology Branch is currently investigating the development and potential application of direct vestibular displays. The Electrical Vestibular Stimulus (EVS) technology described in this paper uses electrodes located behind the ears to deliver a low-level electrical current in the area of the eighth cranial nerve of the central nervous system to produce a compelling sensation of roll motion about the body's fore-aft axis. In this study, subjects experienced the EVS display while simultaneously observing a large field-of-view visual roll display, and were asked to rate various aspects of quality and magnitude of self-motion. The two displays were driven in a sinusoidal fashion at various phase relationships relative to one another. Results revealed that the fidelity of the motion experience depended upon the phase relationship between the two displays. Results also indicated that when an appropriate phase relationship was used, the vestibular display significantly improved the fidelity of the motion experience when compared to a visual-only display.