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A Brief Look Into Visual Perception

Legibility refers to the ease with which the elements, e. g. letters, numbers, symbols can be immediately detected, discriminated, identified from each other.

The information that is visually collected to achieve legibility, begins early in our visually perception process. In a parallel, bottom-up, top-down process, neural activity rides two information-driven waves concurrently. The first wave occurs within the bottom-up process. Information collected by the retinal image passes to the back of our brain along the optic nerve in a series of steps that begin pattern recognition.

Step 1. Features in our visual field, like size, orientation, color, and direction are processed by specific neurons. Millions of these features are processed and used to construct patterns.

Step 2. Patterns are formed from processed features depending on our attention demands. Here, visual space is divided up by color and texture. Feature chains become connected and form contours. Many of these cognitive pattern recognitions are described through Gestalt Principles.

Step 3. Objects most relevant to our current task, are formed after the pattern-processing stages filters them. These visually objects are stored in our working memory, which is limited in its capacity. Our working memory holds only about three visual objects in attention at one time. These visual objects are linked to other various kinds of information that we have previously stored.

While the first bottom-up wave is processing patterns, the second top-down wave is processing which information is relevant to us at that moment and is driven by a goal. In addition, we associate actions that are then primed for our behaviors. So through a series of associated visual and nonvisual information and action priming, we can perceive the complex world around us. For more information about how we perceive visual information, read Visual Thinking for Design.