More information on Gestalt

The principles explained in the Underlying Theories page are not limited to static visuals they include motion and auditory Gestalt too.

There is some criticism of Gestalt principles being merely descriptive rather than  providing a model of perceptual processing. EG:

Koffka K. (192). Perception: An introduction to the Gestalt-theory. Psychological Bulletin 19 531-585. Multistabile perception is the tendency of ambiguous perceptual experiences to pop back and forth unstably between two or more alternative interpretations.

Gestalt does not explain how images appear multistable only that they do.

Movement and sound:

It was long known from the Gestaltists that two identical visual targets moving across each other can be perceived either to bounce off or to stream through each other (Metzger 1934). In 1997 Sekuler et al. demonstrated that a brief sound at the moment the targets coincide biases perception toward bouncing.

Sources

Metzger W (1934) Beobachtungen über phänomenale Identität. Psychologische Forschung 19:1–60

Sekuler R Sekuler AB R Lau (1997) Sound alters visual motion perception. Nature 385:308

This article from Scholarpedia: (http://www.scholarpedia.org/article/Gestalt_principles)

Unresolved issues:

As formulated by Wertheimer Gestalt principles involve a ceteris paribus (all other things being equal) clause (Palmer 1999). That is each principle is supposed to apply given that the other principles do not apply or are being held constant. In case two (or more) principles apply for the same input and they favor the same grouping it will tend to become strengthened; however if they disagree usually one wins or the organization of the percept is unclear. Several examples of the domination of one principle over another are presented above. However although it has been addressed to some extent in the literature (e.g. see Kubovy & van der Berg 2008) the significant theoretical problem of how to predict which principle will win in which circumstances remains to be worked out in much more detail.

Gestalt principles are usually illustrated with rather simple drawings. Ideally it should be possible to apply them to an arbitrarily complex image and as a result produce a hierarchical parsing of its content that corresponds to our perception of its wholes and sub-wholes. This ambitious goal is yet to be accomplished.

It has been suggested that most Gestalt principles are special instances of the overarching Good Gestalt principle in the sense that being continuous closed similar etc are ways of being maximally good ordered simple etc. However although this idea achieves some explanatory economy and unity it does so at the cost of clarity and operationalizability: whereas it May be relatively simple to point out the presence of continuity closure etc it is more difficult to establish what exactly makes a pattern visually good simple unified etc.

One important issue which was not discussed much in classical literature is the origin of Gestalt principles. Why is it that the perceptual input is organized in accord with proximity continuity closure etc? The gestaltists tended to favor the notion that these principles are among the fundamental properties of the perceptual system providing the basis of our ability to make sense of the sensory signals. An opposed view is that the Gestalt principles are heuristics derived from some general features of the external world based on our experience with things and their properties (Rock 1975): objects in the world are usually located in front of some background (figure-ground articulation) have an overall texture different from the texture of the background (similarity) consist of parts which are near each other (proximity) move as a whole (common fate) and have closed contours (closure) which are continuous (continuity). In sum although these principles have been discussed for more than 80 years and are presented in most perception textbooks there are still a number of issues about them that need to be resolved.

Wertheimer M. (192/1938). Untersuchungen zur Lehre von der Gestalt II. Psychologische Forschung 4 301-350. (Excerpts translated into English as Laws of organization in perceptual forms in W.D Ellis (Ed.) A source book of Gestalt psychology. New York: Hartcourt Brace and Co. and as Principle of perceptual organization in D.C. Beardslee & Michael Wertheimer (Eds.) Readings in Perception Princeton NJ: D. Van Nostrand Co. Inc.).