The Formation and Development of Perceptual Activity

Considerable data are available in the field of perception to demonstrate that a given object, shown repeatedly to a subject, induces non-identical cognitive effects. This is manifested in the fact that the given object is reproduced in differing ways by the subject or that the manner in which it governs his acts varies. These differences cannot be explained in terms of properties of stimulation, nor are they directly explainable by the morpho-physiological mechanisms of perception, inasmuch as both may be relatively invariable. Nor can we be fully satisfied with the exceedingly general explanation of these facts by the assertion that repeated presentations of an object cause ever newer aspects to be discovered. Finally, to fall back upon the concept of "set" merely postpones solution of the problem, for sets themselves and the mechanism of their appearance and operation are themselves in need of clarification. It goes without saying that, in analyzing these facts, it is important to take into considerati...