Perception, narrowly defined, is awareness. Most of what we perceive is perceived visually— perhaps three quarters or more (Barry, 1994; Hansen, 1987). Perception is sensing, and visual perception is seeing. Studies of perception at that level are beyond the scope of this chapter. Still, the relevance to visual literacy of perception more broadly defined is obvious. Barry (1994) defines perception as “the process by which we derive meaning from what we see, hear, taste, and smell” (p. 114, emphasis added). Seeing images and deriving meaning from them is both an act of perception and a necessary condition of visual literacy.
In his book on visual information, Pettersson (1993) includes a chapter on perception that assumes the broadest kind of definition of the term. Included in his chapter is a section on the physiological aspects of vision, including reference to studies of his own and of others about eye movements, fixations, and scanning as physical attributes of seeing-to perceive. There is also a section on picture perception, again supported by reports of his own and others’ research. In the smorgasbord of topics that he includes are subliminal reception, illusions, visual imagery, and a cognitive model of perception. From the mass of research that Pettersson reviews and describes, he reached the following eclectic conclusions (among others):
• All visual experience is subject to individual interpretation.
• Perceived image content is different from intended image content.
• Even simple pictures may cause many different associations.
• A given set of basic elements can be combined to form completely different images.
• The design of a picture can be changed a great deal without any major impact on the perception of the image contents.
• Content is more important than execution or form.
• Picture readability is positively correlated with both aesthetic ratings and assessed usefulness in teaching.
• Legends should be written with great care. They heavily influence our interpretation of image content.
• To a large degree, readers see what they are told to see in an image.
• There seems to be no major difference between genders in interpretation of image contents.
• Students display poor pictorial capabilities.
• We must learn to read image content.
Barry (1994) has written an elaborate piece on perceptual aesthetics and visual language. Although most of her chapter is expository and theoretical, she makes some interesting connections. For example, she brings together meaning and feeling and explains how the perceptual process serves as a link. She provides a useful conception of Gestalt psychology as a basis for aesthetic theory. Others who have concerned themselves with visual aesthetics are Arnheim (1979) and Curtiss (1987).
Winn (1993) has written a new two-part chapter on perception for the revised Fleming and Levie (1993) book of principles from the behavioral and cognitive sciences. In the Winn chapter, conclusions from the research are stated as principles, and each principle is then briefly explained. Many of the explanations cite the underlying research. In Part I, most of the 31 perception principles are generalized, but a few address visual perception directly. For example, these four research-based principles relate directly to visualization and visual literacy:
1.3. Distinguishing between figure and ground is one of the most basic perceptual processes. Early perceptual processes are active in figure-ground organization.
1.5 b. Whether people see the “big picture” or details first depends primarily, in vision perception, on the size of the visual angle, that is, on the size of the image relative to the whole visual field.
1.6. A horizontal-vertical reference system seems to be fundamental to perceptual organization. There is also a natural tendency for people to partition images into left and right fields.
2.5. If none of these factors [sequence, organization, or composition] comes into play, there is a tendency for literate viewers to “read” visual messages in the same way they read text—for English speakers, that means from left to right and top to bottom.
Roberts A. Braden
California State University at Chico