Functional Aesthetics for Data Visualization

CHAPTER 1The Science Behind Perception

The human visual system is quite intricate and remarkable. Cameras often serve as a common reference point when first starting to understand the mechanics of the eye itself. Like the lens on a camera, the cornea serves as the outermost lens and window to the world, protecting the viscous eye but letting light enter. The colorful iris acts as a shutter mechanism to control light. Similar to the camera metaphor, the eye can expand and contract to focus properly. While there are optical similarities between a camera and the eye in the way they capture an image, a camera does not have perceptual or cognitive abilities and the metaphor starts to break down when we get to how the brain interprets this information.

Seeing and Understanding Imagery

Beyond a picture that we perceive, our brains take this visual information and perform calculations on it. Think about it as you drive. You are analyzing in real time the placement of your car against the other cars as well as how fast the other cars are moving. When you buy a new car, your perception has to adjust from that vantage point: your new car might be smaller or larger, affecting all of your calculations and processes. Vision is an information processing phenomenon where neurons in our brain perform calculations on the signals so that we reason about what is in the imagery we see and how we act on it. In other words, it's not a simple picture or movie that we perceive.

Long before Isaac ...