|
Gestalt psychology, a term derived from the German term 'gestalten' or organised wholes, is a theory of perception which enjoyed a time as the most popular theory during the early twentieth century. Perceptual psychology aims to find out how we attatch and derive meaningful symbols from the simple electrical impulses that make us aware of light, dark and colour in our visual systems. While vision goes on between the eye and the brain, percepion is a process entirely within the mind. Gestalt theory maintains that the mind has innate organisational abilities which allow us to deconstruct a whole image into various components without having to actively analyse them. The guiding principal of Gestalt psychology is that the larger picture will be seen before its component parts. This has particular relevance for the visual arts, and is effectively the psychological equivalent of the old saying 'the whole is bigger than the sum of its parts.' This was proved by Navon, who found that when people were briefly presented with large outlines of letters composed of smaller letters, the large letter was identified but not the small one.
The second guiding principle of Gestalt psychology is that, when there are a number of possible interpretations, we automatically choose the one for which the least additional information is required. The organisational process is an innate one that is not capable of being selective.
The principles which govern this organisational system are known as the 'laws of Pragnanz.' There are generally acknowledged to be six of these, although there are sub categories of each.
Proximity: Objects which are close together are likely to be seen as a group. For example, look at the following line.
III II IIII I
You are likely to percieve this as four separate groups, comprising three, two, four and one members respectively, rather than to view it as a line of ten I s. This doesn't only apply to visual perception, think for example of music, percieved as a melody rather than a procession of single notes.
Closure: This applies to drawings more than anything else. When the outline of an object is left unfinished, as long as the gap is less than half the total circumference then the object is identified and percieved as whole rather than as a different shape or assortment of shapes. Draw a set of concentric circles and then erase about a tenth of each one. You will still percieve it as a pattern of circles. The only exception is if you erase the circles in the same area, thus creating an apparent line of erasedness. This line is the result of the continuity principle.
Continuity: if two lines intersect then the two lines may realistically be any combination of four divergences from the meeting point, but they are percieved as being the combination of the two most similarly orientated of four smaller divergences. For example, a cross is percieved as two straight lines bisecting each other rather than two right angles positioned next to each other.
Similarity: When there are different sets of objects on view then they are percieved as groups rather than individual objects.
A A A A A
J J J J J
A A A A A
is percieved as three lines of similar letters rather than ablock of fiteen or five sets of AJAs.
Common Fate: If some identical objects move one way and others go a different way then they are percieved in trhe groups in which they move rather than as individuals. For example, if from a line of four which is percieved as a line of four two are rotated left and two are rotated right then they cease to be identical and are grouped as a result of their fate.
Figure-Ground: Probably the most important of the Gestalt concepts is the theory that in any visual array there is always one object which will be percieved as the object and everything else as a background to it. The object is usually defined by being in some way different, whereas the background will be undistinctive. We concentrate innately on the figure, and this means that illusions may be used to trick the senses. For example the Rubin vase can be seen either as a vase on a black background or two faces in profile on a white background. This ability to manipulate what the viewer focuses on has implications in the visual arts.
The Ambiguous 'Good Figure': The main problem with Gestallt is that it relies so heavily on the reversion of human perception to figures which are in some way acceptable to our perceptual system, but that it has no criteria as to how to create such a figure, or the diference between it and an unacceptable figure. For example, overlapping a square and a circle creates a new shape, but will generally still be percieved as being a sqaure overlapping a circle. The way we see shapes that we are more used to can be attributed either to our learning, which would imply that there is a development in perceptual ability, or just that they are more simple and easily recognisable, which would have little bearing.
Gestalt's fall from popularity is mainly attributable to this and other unresolved questions, most notably that it does not apply to 3D vision in the same way as to 2D drawings. However, it has still proved a useful base in the ongoing quest to explain perception in psychological terms.
| 
