Both von Ehrenfels and Edmund Husserl seem to have been inspired by Mach's work Beiträge zur Analyse der Empfindungen (Contributions to the Analysis of the Sensations, 1886), in formulating their very similar concepts of Gestalt and Figural Moment, respectively.
Early 20th century theorists, such as Kurt Koffka, Max Wertheimer, and Wolfgang Köhler (students of Carl Stumpf) saw objects as perceived within an environment according to all of their elements taken together as a global construct. This 'gestalt' or 'whole form' approach sought to define principles of perception -- seemingly innate mental laws which determined the way in which objects were perceived.
These laws took several forms, such as the grouping of similar, or proximate, objects together, within this global process. Although Gestalt has been criticized for being merely descriptive, it has formed the basis of much further research into the perception of patterns and objects (ref: Carlson, Buskist & Martin, 2000), and of research into behavior, thinking, problem solving and psychopathology.
The theoretical principles are the following:
Based on the principles above the following methodological principles are defined:
Emergence is demonstrated by the perception of the Dog Picture, which depicts a Dalmatian dog sniffing the ground in the shade of overhanging trees. The dog is not recognized by first identifying its parts (feet, ears, nose, tail, etc.), and then inferring the dog from those component parts. Instead, the dog is perceived as a whole, all at once. However, this is a description of what occurs in vision and not an explanation. Gestalt theory does not explain how the percept of a dog emerges.
Reification is the constructive or generative aspect of perception, by which the experienced percept contains more explicit spatial information than the sensory stimulus on which it is based.
For instance, a triangle will be perceived in picture A, although no triangle has actually been drawn. In pictures B and D the eye will recognize disparate shapes as "belonging" to a single shape, in C a complete three-dimensional shape is seen, where in actuality no such thing is drawn.
Reification can be explained by progress in the study of illusory contours, which are treated by the visual system as "real" contours.
See also: Reification (fallacy)
Multistability (or multistable perception) is the tendency of ambiguous perceptual experiences to pop back and forth unstably between two or more alternative interpretations. This is seen for example in the Necker cube, and in Rubin's Figure / Vase illusion shown to the right. Other examples include the 'three-pronged widget' and artist M. C. Escher's artwork and the appearance of flashing marquee lights moving first one direction and then suddenly the other. Again, Gestalt does not explain how images appear multistable, only that they do.
Invariance is the property of perception whereby simple geometrical objects are recognized independent of rotation, translation, and scale; as well as several other variations such as elastic deformations, different lighting, and different component features. For example, the objects in A in the figure are all immediately recognized as the same basic shape, which are immediately distinguishable from the forms in B. They are even recognized despite perspective and elastic deformations as in C, and when depicted using different graphic elements as in D. Computational theories of vision, such as those by David Marr, have had more success in explaining how objects are classified.
Emergence, reification, multistability, and invariance are not separable modules to be modeled individually, but they are different aspects of a single unified dynamic mechanism.
The fundamental principle of gestalt perception is the law of prägnanz (German for conciseness) which says that we tend to order our experience in a manner that is regular, orderly, symmetric, and simple. Gestalt psychologists attempt to discover refinements of the law of prägnanz, and this involves writing down laws which hypothetically allow us to predict the interpretation of sensation, what are often called "gestalt laws". These include:
Productive thinking- is solving a problem with insight.
This is a quick insightful unplanned response to situations and environmental interaction.
Reproductive thinking-is solving a problem with previous experiences and what is already known. (1945/1959).
This is a very common thinking. For example, when a person is given several segments of information, he/she deliberately examines the relationships among its parts, analyzes their purpose, concept, and totality, he/she reaches the "aha!" moment, using what is already known. Understanding in this case happens intentionally by reproductive thinking.
Other Gestalts psychologist Perkins believes insight deals with three processes:
1) Unconscious leap in thinking. .
2) The increased amount of speed in mental processing.
3) The amount of short-circuiting which occurs in normal reasoning.
Other views going against the Gestalt psychology are:
1) Nothing-Special View
2) Neo-Gestalts View
3) The Three-Process View
Gestalt laws continue to play an important role in current psychological research on vision. For example, the object-based attention hypothesis states that elements in a visual scene are first grouped according to Gestalt principles; consequently, further attentional resources can be allocated to particular objects.
Gestalt psychology should not be confused with the Gestalt therapy of Fritz Perls, which is only peripherally linked to Gestalt psychology. A strictly Gestalt psychology-based therapeutic method is Gestalt Theoretical Psychotherapy, developed by the German Gestalt psychologist and psychotherapist Hans-Jürgen Walter.