Abstract

Some authors have explained the illusory shrinkage of a partially "occluded" figure as due to amodal completion. Two experiments were carried out by the method of adjustment to test this hypothesis. The first experiment exploited the properties of the so-called "Helmholtz-Ratoosh law" to test whether a figural shrinkage is also present in a pattern in which amodal completion should not occur. The second experiment was aimed at checking whether stereoscopical displacement of the "occluded" figure "behind" or "in front of" the "occluding" one is capable of affecting the amount of shrink-age. In both cases, results tend to show that the amount of shrinkage of the "occluded" figure is not affected significantly by the presence of amodal completion.