Commentary on O'Regan, J. Kevin and Noë, Alva (2001) A Sensorimotor Account of Vision and Visual Consciousness

Abstract word count: 35 words
Main text word count: 990 words
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Entire text word count: 1025

Whither Visual Representations? Whither Qualia?

Jonathan Cohen
Department of Philosophy
University of California, San Diego
9500 Gilman Drive
La Jolla, CA 92093-0119
joncohenREMOVETHIS@aardvark.ucsd.edu (omit text in caps, which reduces automated spam)
http://ruccs.rutgers.edu/~joncohen/cohen.html


Abstract: This paper makes two rejoinders to O'Regan and Noë. It clarifies the status of visual representations in their account, and argues that their explanation of the (according to them, illusory) appeal of qualia is unsatisfying.


Main text:

Whither Visual Representations?

O'Regan and Noë argue against conceiving of vision in terms of pictorial internal representations. They urge that "there is no 're'-presentation of the world inside the brain: the only pictorial or 3D version required is the real outside version" (12). While their arguments against the existence of pictorial representations in the brain are persuasive, they are unsuccessful in showing that there are no internal visual representations.1

There are a number of traditional, if quotidian, reasons for positing internal, visual representations, and O'Regan and Noë say nothing that would undermine these. For example, you can remember the color of the coffee cup you used yesterday morning, even though it is now hidden in a cabinet (because the cup is hidden, your ability can't be explained by the "outside memory" of section 4). Although the details might vary, the standard explanation of this ability seems to require appeal to a persisting mental state that is (i) selectively sensitive to the coffee cup and its properties (e.g., its color), (ii) causally efficacious with respect to later processing, and (iii) generated in part by past visual interaction with the cup. Such a state is traditionally counted a representation because of feature (i) --- it represents the coffee cup. It is traditionally counted as internal/mental because of feature (ii) --- it can be recalled and manipulated by later mental processes, and can survive radical alteration or even destruction of its object (the cup). And it is traditionally counted visual because of feature (iii) --- it is generated and maintained by the visual system.2

There are many other standard motivations for visual representations, most of which take the form of phenomena for which explanations are possible if there are visual representations, but not possible otherwise. To take a few examples almost at random, it is hard to explain perceptual priming, perceptual learning, or the dependence of recall time for visually presented items on their number, without supposing that the visual system forms representations of the world, and that these representations are operated on by mental processes with certain properties (e.g., effects on recall, chronometric properties). Significantly, there is no reason to suppose that the visual representations required by these explanations must be pictorial, that they are retinal projections, or that they otherwise exemplify geometric properties. On the contrary, accepting the standard explanations commits one only to the existence of internal, causally efficacious states that represent the world and are generated by the visual system.

I see no reason that O'Regan and Noë should deny the existence or significance of such states; consequently, I see no reason for them to deny the existence or significance of internal visual representations.

Whither Qualia?

Although O'Regan's and Noë's position on the nature of qualia amounts to a familiar brand of eliminativism, they supplement this position with a novel proposal about the source of the widespread belief in qualia (section 6.4).3 O'Regan and Noë propose that subjects' belief in qualia has two main sources. First, subjects "overlook the complexity and heterogeneity of experience and this makes it seem as if in experience there are unified sensation-like occurrences" (35). Second, the continuous availability of features of the visual scene to our attention gives subjects the false impression that they "continuously represent those features in consciousness" (35).

Unfortunately, I don't see how these points explain subjects' belief in qualia. Grant that subjects make the errors O'Regan and Noë attribute to them; if these errors explain the illusion of qualia, then removing them should make that illusion disappear. Suppose, then, that subjects came to appreciate the complexity underlying visual experience --- they learn about inhomogeneities in retinal photoreceptor densities, eye movements, color constancy mechanisms, and so on. I don't see how knowing about the complex structure of events that causally sustain our visual experiences would impugn subjects' belief that experiences have a certain qualitative character: belief in qualia seems to derive from subjects' phenomenological impressions about their own experiences, not from naive speculation about the simplicity of visual mechanisms. Now consider the other purported source of the illusion --- subject's erroneous impression that they continuously and consciously represent visual features that are in fact unrepresented. Again, grant that subjects hold this erroneous belief. Why should this make them susceptible to a belief in qualia? Once again, correcting this erroneous belief seems not to affect a subject's belief in qualia: even a subject convinced she did not maintain continuous conscious representations of features in the visual scene might hold that her experience of looking at the scene has a qualitative character.4

Because a subject could believe in qualia without holding either of the two other beliefs O'Regan and Noë mention, it is hard to see these beliefs as the sources of the widespread appeal of qualia. If qualia are an illusion, they must have their source elsewhere.


Footnotes:

1I am unsure whether O'Regan and Noë mean to show this, or whether they intend to show only that, if there are such representations, they cannot be pictorial. Unfortunately, many of the formulations in the text are ambiguous on this point.

2 It is not counted visual because it can be seen, or because it exemplifies geometric or color properties.

3 O'Regan and Noë also argue that belief in qualia is not widespread because naive subjects don't understand the question "what is it like to look at the piece?" as a request for elucidation of the qualitative aspects of their experiences (section 6.5). I find this response unconvincing: surely the supposition that subjects have phenomenal access to qualia is compatible with their understanding the above question as not soliciting commentary about qualia. Putting this aside, it seems strange that O'Regan and Noë argue in section 6.5 that the illusion is not widespread among ordinary subjects when they attempt to explain its source in ordinary subjects in section 6.4: if the illusion is not widespread, there should be nothing to explain.

4 So it seems to me. Presumably these issues are empirically testable.