Perceived distance and the perceived speed of self-motion: Linear vs. angular velocity?

Abstract

Experiments are reported in which it was found that, with the angular speed of a visual surround held constant, the perceived speed of rotary self-motion increased linearly with increasing perceived distance of this surround. This finding was in agreement with a motion constancy equation derived from a consideration of object-referred motion perception. Since information concerning distance is necessary for the perception of linear but not angular speed, this finding supports the conclusion that visually perceived rotary self-motion perception is dependent upon perceived linear surround motion at least in the horizontal plane. The visual motion constancy mechanism which operates for object-referred motion can apparently not be switched off for the special case of self-motion perception. © 1975 Psychonomic Society, Inc.