What parts does experience have?

Here’s a kind of naturalistic mistake about what’s “really” in experience that seems to turn up in a lot of places: It’s the idea that some thing like 2-D “frames” of vision are “present” (and maybe all that’s really present) in visual phenomena. (This seems to show up not only in “naive” assessments, but in some parts of pretty serious writing on the phenomenological structure of experience.) But in the end, it seems like a pretty basic and fundamental mistake, where theorizing about the production of experiences gets run together with analyzing their character or content as experiences.

This mistake comes in two forms — both the “there are only frames as real parts of experience” form and the “frames are real parts of the experience (along with other things)”. Both are wrong; and it’s more interesting to take on the latter (weaker) version, since if you nail that, you nail the whole thing.

The most straightforward attack on this is really a phenomenological one. Consider carefully the perceptual presentation of a rectangular surface which is oriented in some way in space other than directly perpendicular to the line of sight of the subject — a table top, or the cover of a book resting on a flat surface, for example, where the subject is standing some small distance away. This is, of course, a common and natural situation that we encounter in everyday life.

And although this is definitely a bit of visual presentation that’s much more vivid and compelling in the real world, a picture here will at least help us talk about it. So, here’s a couple of simple real-world tables.

What shape does the top of the table in the foreground appear to be? Surely, at first glance, there’s no doubt that it appears to be rectangular, with the rectangle having an obvious oblique orientation in 3-D space — its closest edge is lower in the visual field, and the visible surface is facing upwards.

Of course, since I know a few utterly mundane things about geometry, optics, perspective, and projection (ones most everyone knows), I realize that what is literally projected to the eye at any given instant is some 2-D projection or image of the current scene, and in that 2-D projection, the part of the image that corresponds to the rectangular surface in the world is some odd not-quite-parallelogram quadrilateral.

This shape’s bottom edge is longer than its top edge; and none of the angles at the corners of the figure are identical with any other, or very close to right angles.

It takes a special act of focusing to bring out this shape, and to answer the most mundane of questions about it (e.g., which angle sharper — the one at the top of the figure, or the one at the bottom?). And often — especially in the real world case — it’s pretty close to impossible for most of us. People learn to do it better when they learn to draw well; but for most of us ordinary folks, the 2-D shapes optically projected by the 3-D layout onto, say, the retinal image, are pretty deeply unavailable to conscious introspection.

Given that, what possible reason is there to think that these shapes are “really” part of the stream of experience? Unless you think that all synthesis of incoming data must be done in experience, even a naturalistic assessment that somewhere in the perceptual system, this 2-D quadrilateral must be represented (and in my more radical moods, I’ll even question that) shouldn’t lead you to thinking that this representation is in any way a part of our conscious experience.

Other examples aren’t hard to find. Here’s a mundane one: Lightness (and color) constancy across different apparent illuminations is a very robust visual phenomenon. Again, the real world is best; but here’s a decent picture for illustration. The two squares with red dots are actually the same local shade, but look very difference because of some implicit information about their illumination. But there’s no reason to think that there’s any part of our experience such that the two squares are really experienced as the same, even though we might believe they shine the same level of light on the eyes.

Or in speech perception, think about the kind of refocus of attention from our normal listening to speech as meaningful utterance, to something like the focus on the stream of phonemes that we do when we try to do phonological transcription of utterances in our own native tongue. That fact that we can (with practice and training) do the refocus doesn’t mean that the phonological stream is “already there” at all, and especially doesn’t entail that it was already there as a part of the content of the experience. Whether that stream is there or not in pre-conscious processing is an empirical matter of human psycholinguistics. But the idea that it’s not there already in experience seems, if not conclusively proven, at least pretty strongly argued by the sort of considerations raised above.

As Merleau-Ponty famously points out, conscious analysis of the structure of experience should not be expected to retrace a path by which it was consciously synthesized. As we think about the structure of the experience and analyze, alter (by tracing shapes, intentionally blurring, or the like), and attempt to explain it, we shouldn’t expect that we’re necessarily unearthing the real already-present experiential structure, but more likely conjecturing aspects of what might go into a naturalistic and explanatory account of the mechanisms by which we — or better, our brains and sensory apparatuses — manage to cause such experiences to occur.

08. January 2006 by Ron
Categories: perception, phenomenology, philosophy | Leave a comment

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