Moving visual scenes influence the apparent direction of gravity.

Abstract

It is shown that an observer viewing a wide-angled display rotating about its line of sight develops a feeling that his body is tilted and has the illusion that a vertical straight edge is tilted in a direction opposite to that of rotation. Experiments on subjects who monocularly viewed rotating disks with various settings within restricted fields of view are described to substantiate these findings. Displacement of the perceived vertical increased to a maximum of average 15 deg when the stimulus speed increased to 30 deg per sec.