Velocity not acceleration of self-motion mediates vestibular-visual interaction

Scene-Motion Thresholds During Head Yaw for Immersive Virtual Environments

In order to better understand how scene motion is perceived in immersive virtual environments, we measured scene-motion thresholds under different conditions across three experiments. Thresholds were measured during quasi-sinusoidal head yaw, single left-to-right or right-to-left head yaw, different phases of head yaw, slow to fast head yaw, scene motion relative to head yaw, and two scene illumination levels. We found that across various conditions 1) thresholds are greater when the scene moves with head yaw (corresponding to gain < 1:0) than when the scene moves against head yaw (corresponding to gain > 1:0), and 2) thresholds increase as head motion increases.

Scene-Motion Thresholds Correlate with Angular Head Motions for Immersive Virtual Environments

To better understand motion perception in immersive virtual environments, we conducted a user study to quantify perception of scene motion as subjects yawed their heads. We measured psychometric functions of scene-velocity thresholds for different head motions and then extracted 75% thresholds, creating scene-velocity thresholds as functions of three measures of head motion: 1) Angular Range, 2) Peak Angular Velocity, 3) and Peak Angular Acceleration. We also measured scene-velocity thresholds for four phases of head motion: 1) the Start of the head turn, 2) the Center of the head turn, 3) the End of the head turn, 4) and All of the head turn. Scene-velocity thresholds increased as head motion increased for all tested conditions.