Also reports by Johansson and by Reynolds. These invariants under transformation will only exist if there is transformation, not in a silhouette as a single projection. The perception of motion should not be confused with perception of the depth-shape of the object moved. Results with the shadow-apparatus yielding approach of an apparent object. Gibson in Brit.
Perceptual constancy is supposed to depend on stimulus-invariants.
Event-perception is supposed to depend on certain local transformations of the ambient array. Other types of perceptual constancy occur, of course, and the theory of stimulus-invariants may also be applied to them.