THE PLANE OF APPARENT REVERSAL (PAR) OF THE ROTATING TRAPEZOID ILLUSION WAS OBTAINED FOR MALE SS, WHO MONOCULARLY OBSERVED WHITE, UNPATTERNED ROTATING TRAPEZOIDS OF VARIOUS SHAPES AND AT SEVERAL DISTANCES. THE PAR WAS AFFECTED BY BOTH THE AMOUNT OF LINEAR PERSPECTIVE AND THE HORIZONTAL VISUAL ANGLE SUBTENSE OF THE ROTATING TRAPEZOID. THE CUE TO PAR WHICH WAS DOMINANT DEPENDED UPON THE NATURE OF THE REQUIRED JUDGMENTAL TASK. (PsycINFO Database Record (c) 2006 APA, all rights reserved)