Gestalt effects in psychology of cognition refer to the form-forming capability of our senses. Examples are mostly taken from the visual sense and the cognition of two-dimensional forms, because this is easiest to present. The same rules are responsible for form-forming in other senses as well as in relation to three dimensions and time. For example, nearby lights that are switched on / off can be seen as a running dot gestalt. Gestalt refers to the perception of wholeness formed by the human brain.

Examples

A simple example for the gestalt processing capacies of the brain is the following:

	 *************
	
	 *************
	
	 *************

Probably, the first thing you see is three lines (of stars), and not single stars or a rectangle.

Another simple example would be:

	 + - - - - - +   
	 :           :   +---+
	 :           :   |   |
	 + - - - - - +   +---+

Characters? Dots? Lines? The most likely thing you'll see will be two rectangles in this case.

And a last example:

	  + - - - - - - - - +
	  :                 :
	  :  /\ /\   +---+  :
	  :  \/ \/   |   |  :
	  :          +---+  :
	  + - - - - - - - - +

Three geometrical forms lying on a tablet, grouped into two groups, consisting of the two rhombi left and the square right? Or alphanumerical characters?

Gestalt laws in two-dimensional visual cognition

Given the example of two-dimensional drawings, there are at least three principal gestalt laws at work guiding us to see figures and whole forms instead of simple lines and curves.

Figure and Background

Human cognition arranges surfaces in forms which are recognized as the actual figure, and in forms which are recognized as background to the figure. In some geometrical arrangements the relation between figure and background isn't clear. In that case we see one part of the image as figure and the other part as background, until they change.

Responsible for recognizing surfaces as figure are amongst others a closed outline and a small area relating to the seen background.

Internal Arrangement

If there are lines forming overlaying figures, we see this as overlay of those figures whose outline has the least changes of direction. In generalisation, this is known as as pregnance principle: if there are alternative figures that could be seen, we see the figure or gestalt which is based on the most simple, uniform, closed, symmetrical form.

Deepness

The pregnance principle is seen best in the cognition of three dimensions or deepness in two-dimensional pictures or drawings. A simple drawing of a cube is seen as a cube -- and not as flat arrangement of surfaces.

The word Gestalt

Gestalt itself is a German word meaning something like form, whole figure. It was probably first used in psychology by the German psychologists Max Wertheimer, Wolfgang Köhler and especially Kurt Koffka of the Berlin school of psycho-physics (1890-1920).

Usage

Gestalt psychology is used in the fields of usability studies and industrial design. For example, the best arrangement of buttons (in functional groups, the single buttons of equal size) in an interface is related to gestalt effects.

Gestalt therapy is a psychological school that transfers the gestalt effects from optical perception to the cognition of figures, forms and wholes in social groups. "Its theory provides a system of concepts describing the structure and organization of living in terms of aware relations."