Definition

The visual systems pattern perception and recognition capabilities can be capitalized upon in display design. There are simple shapes and colors that are very rapidly processed and recognized. This processing is termed "pre-attentive" because it occurs automatically prior to conscious attention. We can use knowledge of pre-attentive processing in the design of visual displays to organize information for rapid recognition. Pre-attentively processed items are those that "pop-out" in our perception. These are based on Gestalt principles, an early approach to psychophysics that has been supported by subsequent research findings in perception and neurophysiology. (Figures adapted from Colin Ware's web-posted lecture slides, Data Visualization Lab, University of New Hamphsire.)

Proximity - Objects near each other tend to be perceived as a unit.
Continuity - Objects arranged or connected by a smooth curve tend to be perceived as a unit.
Closure - Figures with gaps tend to be perceived as closed complete figures.
Similarity - Objects similar to each other tend to be perceived as a unit.