Vestibular cues and virtual environments: choosing the magnitude of the vestibular cue

The design of virtual environments usually concentrates on constructing a realistic visual simulation and ignores the non-visual cues normally associated with moving through an environment. The lack of the normal complement of cues may contribute to cybersickness and may affect operator performance. Previously (1998) we described the effect of adding vestibular cues during passive linear motion and showed an unexpected dominance of the vestibular cue in determining the magnitude of the perceived motion. Here we vary the relative magnitude of the visual and vestibular cues and describe a simple linear summation model that predicts the resulting perceived magnitude of motion. The model suggests that designers of virtual reality displays should add vestibular information in a ratio of one to four with the visual motion to obtain convincing and accurate performance.