Gestalt Perception Effects
This ability to make sense of the visual world around us by creating a map of what things are rather than what they look like can be described through the theories of Gestalt psychology. This particular psychological perspective stems from the now-familiar idea that “the whole is greater than the sum of its parts.” In fact, the German word “Gestalten” can be translated to mean “configuration,” and it follows that Gestalt theorists believe that our perceptive abilities are based not on the individual elements in our surroundings but on the way they are arranged and how they interact |Walker, 1966|. For instance, if there was a tall fence in our field of view and just above that fence was the head of our neighbor, moving from left to right, we would likely interpret it to be our neighbor walking across their lawn rather than our neighbor’s head mysteriously floating around. But why? We cannot see all of our neighbor’s body and thus cannot be sure that they are “all there,” however we make the connection that heads do not usually float around on their own and should therefore be attached to a body that causes the movement. In short, we do not need all of the visual information about an object to know what that object is if that object creates the same experience as that of something that we have encountered before. A simpler example can be seen in the following image, where six unconnected lines are arranged in an open contour. What do you see?
fig. 9. example of the Gestalt principle of closure.
Did you see a cube? Why? There is no cube in that figure except the one that your mind assumes exists because the lines describe what could be interpreted as the edges of such a cube. Gestalt perceptual theory provides principles of how our visual and cognitive systems work in conjunction to make meaning of the visual world, most of which relate most directly to two-dimensional images (i.e. drawings). The line-cube figure above is an example of closure, in which our minds complete or “fill in” an incomplete image to make it have meaning. Other principles include good continuation, similarity, and apparent motion |Walker, 1966|. Figures 10, 11, and 12 include examples and explanations of these principles.
fig. 10. example of the Gestalt principle of good continuation. when looking at a), do you see two lines crossing — as in b), or two lines such as in c)? Image b) represents the typically assumed paths of the series of dots, encouraging good continuation.
fig. 11. example of the Gestalt principle of apparent motion. in this particular array of dots, do the like-colored dots visually produce a zig-zag or back-and-forth motion? This example is similar to the effect of a traffic light warning sign with lights on either side of the sign that flash in sequence; the lights themselves do not move, however the visible light moves back and forth from one side to the other.
fig. 12. example of the Gestalt principle of similarity. do you see rows or columns of like-colored dots? We tend to group like items together even if other possible ordering systems are visually available.
These principles could be considered as subcategories of the Gestalt Law of Prägnanz; this “law” is predicated on the belief that we organize our perception of our environment so that it becomes as simple and orderly as possible (i.e. so that it “makes sense”). Typically shortened to an understanding that “good figures” — those that are simple, symmetric, and balanced — aid in determining this organization.
fig. 13. example of the Law of Prägnanz. when looking at a), do you see the intersection of two shapes — as in b), or three nestled shapes such as in c)?
Figure 13 presents a situation in which a pair of intersecting lines create closed contours. Do you see the overlapping of a circle and a square (b)? Or three closely-nestled irregular shapes (c)? At first glance we perceive the image as two simple geometric shapes overlapping — our minds make this assumption almost immediately; to see the three irregular shapes, we must make a conscious effort to intentionally focus our attention to the area of overlap to determine if, in fact, three shapes exist in the image.