Plato's Cave: Implications

Implications of Plato's Cave

The implications of plato's cave are that we can view the world around us not only as a scientist observing the physical world, but also as a perceptual scientist exploring a rich and complex internal representation. Whatever features or properties are manifest preattentively in this apparently external world must be properties encoded in the internal representation. As such, it becomes immediately apparent by inspection, that this internal percept contradicts some of the most basic assumptions upon which most of our understanding of visual processing are based.

What is Wrong with the Conventional View of Visual Processing?

The conventional view explains the fact that an image of a cup evokes the word "cup" as a symbolic abstraction of that image. Nowhere in any of these schemes however is there a high resolution fully spatial rendition of the actual object being viewed, and yet the most vivid conscious experience of a cup is of a solid three-dimensional presence at the highest perceptual resolution, complete in color, texture and form.

A cup that is held in the hand is clearly not a retinal image, for the retinal image is only a two-dimensional edge representation. Neither can it be the actual physical cup, because that is out beyond the retina, and therefore we can have no conscious awareness of it directly. The difficulty with the conventional view of perception is that it completely ignores this vivid spatial manifestation as if it did not exist. Indeed, the conventional view would predict a consciousness akin to the phenomenon of blindsight.

The Alternative Suggested by Plato's Cave

The implications of Plato's Cave are that the visual system generates a full three-dimensional spatial representation at the highest possible resolution based on the evidence from the senses, in the manner of the [spatial robot analogy] discussed above. The operation of constructing a full three-dimensional model from a two-dimensional image cannot be described as abstraction, but is actually the inverse of abstraction, or reification, a filling-in or extrapolation of a more explicit, specific representation from a less explicit, more compressed one.

It is this function, the construction of a full spatial model of the world, which I believe constitutes the primary function of visual perception. The existence of this internal model, I propose, is identically equivalent to the perception of the object being modeled, whether that model represents a veridical facsimile of the external object, as in true perception, or a distorted misrepresentation, as in the case of illusory or hallucinatory perception. That other function of visual abstraction is, I believe, a secondary function of perception, by no means as essential for practical interaction with the world as the construction of the spatial model. Furthermore, I propose that what abstraction does occur, is an abstraction of that full spatial model, rather than of the impoverished two-dimensional retinal image on which it is based.

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