Wallace B, Cramer D E
Percept Mot Skills. 1975 Feb;40(1):215-9. doi: 10.2466/pms.1975.40.1.215.
Number of apparent reversals for various patterned ellipses and circles was investigated. Ellipses produced significantly more reversals than circles. Patterned stimuli produced a number of reversals dependent upon pattern orientation and corroborated predictions consistent with Power and Day's (1973) general constancy theory for apparent reversals.