According to the Gestaltists, the most basic perception is that of a figure–ground relationship. Perceptual principles that cause the elements of perception to be organized into configurations include continuity, by which stimuli following some pat- tern are seen as a perceptual unit; proximity, by which stimuli that are close together form a perceptual unit; similarity, by which similar stimuli form a perceptual unit; inclusiveness, by which a larger perceptual configuration masks smaller ones; and closure, by which incomplete physical objects are experienced psychologically as complete. The Gestaltists distinguished the geographical (physical) environment from the behavioral (subjective) environment. They believed that the behavioral environment governs behavior. The Gestaltists viewed learning as a perceptual phenomenon. For them, the existence of a problem creates a psychological disequilibrium, or tension, that persists until the problem is solved. As long as there is tension, the person engages in cognitive trial and error in an effort to find the solution to the problem. Problems remain in an unsolved state until insight into the solution is gained. Insightful learning is sudden and complete; it allows performance that is smooth and free of errors. Also, the person retains the information gained by insight for a long time and can easily transfer that information to similar problems. The application of a principle learned in one problem-solving situation to other similar situations is called transposition. Productive thinking involves the understanding of principles rather than the memorization of facts or the utilization of formal logic. The Gestaltists believed that reinforcement for productive thinking comes from personal satisfaction, not from events outside oneself. They thought that memory, like other psychological phenomena, is governed by
the law of Prägnanz. Experience activates a brain activity called a memory process, which lasts as long as an experience lasts. After the memory process terminates, a trace of it remains, and that memory trace influences subsequent memories of similar objects or events. Eventually, a trace system develops that records the features that memories of a certain type have in common. After a memory trace—and to a larger extent, a trace system—is established, the memory of a specific event is deter- mined by the memory trace and by the trace system of similar experiences, as well as by one’s immediate experience.