Abstract
What scientific framework can capture what we might mean by "visual appearance" or "the way things look"? The study of appearance can be operationalized in specific situations, but a general definition is difficult. Some visually guided behaviors, such as changing one's pupil size, maintaining one's upright posture, ducking a projectile, or catching an object when it rolls off the kitchen counter, are not mediated by consciously apprehended appearances. These behaviors use vision in a fast, stereotyped, and automatic way. Compare them to assessing which side of a mountain to hike up, or whether a currently stationary object is at risk of rolling off the counter. These are behaviors probably are mediated by appearance, in the sense of a general-purpose representation that makes manifest to consciousness various estimated scene parameters. One can reason using appearances, and talk about them with other people. Over the years various strategies have been employed to study or exploit appearance: recording unprompted verbal responses from naïve observers; using novel stimuli that cannot be related to previous experience; or using of stimuli that force a dichotomous perceptual decision. We will review these ideas and try to identify additional criteria that might be used. An important realization for this effort is that conscious awareness need not be all-or-none; just as visual sense data are best known at the fovea, appearance is best known at the site of attentional focus.
Meeting abstract presented at VSS 2013