The present experiment examined the effect of independently varying central, vertical, and horizontal visual angles (CVVA, CHVA) on proportion of perceived oscillations with rotating trapezoids. Twenty-five female undergraduates served as Ss. Diminution of the CHVA proved most effective in increasing oscillatory perception (p less than .01), although perceived oscillation was found to be inversely proportional to CVVA and CHVA (p less than .001). The data indicate that Os primarily rely on perceptual cues determined by the horizontal dimension of a trapezoid. When cue discriminability is reduced, the results suggest that O's perceptual response may be a function on individual differences in cue thresholds, and/or response criteria.