Effect of Field Size,Head Motion,and Rotational Velocity on Roll Vection and Illusory Self-Tilt in a Tumbling Room

The effect of field size, velocity, and visual fixation upon the perception of self-body rotation and tilt was examined in a rotating furnished room. Subjects sat in a stationary chair in the furnished room which could be rotated about the body roll axis. For full-field conditions, complete 360° body rotation (tumbling) was the most common sensation (felt by 80% of subjects). Constant tilt or partial tumbling (less than 360° rotation) occurred more frequently with a small field of view (20 deg). The number of subjects who experienced complete tumbling increased with increases in field of view and room velocity (for velocities between 15 and 30° s⁻¹). The speed of perceived self-rotation relative to room rotation also increased with increasing field of view.