Theoretical Approaches

Theories serve as frameworks to organize facts and as springboards to launch new hypotheses. Some theories in perception are loose collections of assumptions, often unexamined by empirical researchers, and some are well developed and carefully constructed explanatory systems. All empirical research is conducted in the context of some type of theory. The questions asked, the research methodology employed, and the interpretation of the findings are all deeply colored by the theoretical approach taken. Thus, it is important to understand the variety of theoretical approaches that have driven research in perception if one is to be an informed consumer of that research. Many of the facts of perception are familiar features of our everyday experience. Other facts are sometimes surprising laboratory findings. All are dependent on a theory for an explanation of how that fact came to be, and what it tells us about the workings of our perceptual systems.

Consider a sample of facts that a theory must explain: The perceptual world (what we see, hear, smell, taste, and feel) seems to be closely related to what is actually there. Aspects of the three-dimensional (3-D) structure of the world can be known: moving objects appear to move; surfaces appear stable; the perceived attributes of the contents of the visual world (size, shape, color, etc.) remain constant, even as our viewing position changes; the perceptual world is characterized by a high degree of organization and structure; it is a reasonably reliable guide to successful action. Some readers will greet this list with bemusement. Why, they may wonder, is any of this problematic? We see moving objects because objects do move; objects appear to have constant size and shape because these qualities are, in fact, constant. We see, hear, smell, taste, and feel the world as we do because the world is what it is. This stance is sometimes called naïve realism.

There is a flaw in the naïve realist position: The naïve realist conflates the facts of the world and the facts of perception. Some qualities of the world are not perceptible to us (the distance to the moon, the freshness of a flower), whereas other qualities may be perceived but inaccurately (the distance to the next mountain, the brightness of one surface in contrast to another). The perceptual world of the honeybee is different from ours. A freshly opened (and thus nectar laden) flower reflects more ultraviolet light than a day old bloom, a beacon to the foraging bee, but undistinguished from its neighbors to us. The qualities of a glass of wine are the same before and after we take a wine-tasting class, but the qualities of our experience surely change. It is how the facts of the world become the facts of perception that is the problem for any theory of perception. Naïve realism has been soundly rejected by the scientific community. The major modern theoretical approaches to the explanation of visual perception are reviewed in this entry, with particular attention to the characterization of the problem and the research questions the approach has motivated.

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