Thursday, May 27, 2010

Initial problems defending conceptualism

This is Part 5 of the serialization of the long version of my paper, "Color-Consciousness Conceptualism," the short version of which appeared in the Second Annual Conference of Consciousness Online. This post contains sections 6-6.5 of the paper.

6. The First Approximation and its problems
6.1. Problems facing the First Approximation

The gist of the First Approximation is to hold that the way blue1 appears in the diachronic presentation is different from the way blue1 appears in the synchronic presentation (blue1 seems the same as blue2 in the diachronic but different from blue2 in the synchronic presentation). This looks to be endorsed by Rosenthal (2005, pp. 188-189) and Gennaro (forthcoming).
One of the main problems immediately faced by the strategy under consideration is the following: Since, (1) by hypothesis, the phenomenal appearance of blue1 in the diachronic context is the same as the phenomenal appearance of blue2 in the diachronic context, and (2) it’s highly implausible that blue1 and blue2 give rise to the same phenomenal appearance when synchronically presented—they are synchronically distinguishable, after all—it seems to follow that (3) the phenomenal appearance of blue1 is different in the synchronic and diachronic contexts. And here is the problem: it needs to be made plausible that blue1 can give rise to different phenomenal appearances in these different contexts.

Now, the problem is not insurmountable, but spelling out just how to surmount it requires some care. And part of what will put pressure on the conceptualist is that the conceptualist will not only need to account for the data regarding diachronic indiscriminability so far described—data from what I’ll call the “Old Experiment”—but also data from a to-be-described “New Experiment”.

I turn now to discuss further these and other challenges that arise for the First Approximation, challenges with which the First Approximation will have varying degrees of success in meeting. They are:

(1) The problem of content: What are the contents of the different experiences in the synchronic and the diachronic presentations?
(2) The problem of mechanism: Why are the contents that way and not some other?
(3) The problem of plausibility: Can it really be made plausible that blue1 seems differently in the synchronic and diachronic contexts?
(4) The problem of the New Experiment: Diachronic indiscriminability can be shown to fail in experimental setups where it’s quite plausible (more plausible than in the Old Experiment) that there isn’t a difference between the way blue1 is experienced in the synchronic and diachronic tasks.

6.2. The problem of content
This looks to be an easy problem for the proponent of the First Approximation to meet. It doesn’t look like there’s any special reason to think that this version of conceptualism will be at a loss of giving an account of what the contents are. They can say, for example, that in the synchronic presentation of blue1 and blue2, the content of the experience is exhausted or matched by the conceptual content expressible as two shades of light blue, one darker than the other. And they can say that, in the diachronic context, the relevant content is expressible as light blue.

Alternately, there might be comparative concepts involved in the diachronic presentations, concepts that are involved in comparisons to the background.

Now, in saying that the proponent of the First Approximation can answer the problem of content is not to say that there aren’t other problems that may arise, but the problem of simply giving an answer to the question of what the contents are is met by the First Approximation.
It needs to be emphasized that, relative to the dialectic, the conceptualist need not give a very specific answer to this question as long as he/she rises to the challenge of making plausible that there are enough concepts for the colors experienced. For the purposes of simplifying discussion, I will take the First Approximation to be giving the following specific answer to the content question: in the diachronic presentation of the chips, the color content of experience is the noncomparative BLUE whereas in the synchronic presentation, the color content is the comparative DARKER BLUE THAN.

6.3. A problem with mechanism?
Given some answer to the question of what the relevant conceptual contents are in the different contexts, a further questions arises of why those contents, and not some other. One way to put a point on it is to consider that the proponent of the First Approximation holds that (1) in the synchronic context but not the diachronic context, a comparative concept, a concept of one shade’s being darker than another, is deployed and (2) in the diachronic context but not the synchronic context, only a noncomparative concept, a concept of being light blue, is deployed. The problem of mechanism might be stated as the problem of supplying some mechanism that explains why the concepts deployed are as described in (1) and (2) as opposed to (1’) comparative concepts deployed in both synchronic and diachronic contexts or (2’) noncomparative concepts deployed in both synchronic and diachronic contexts.

There are two questions that I will address in turn: Why not comparative concepts in both the synchronic and diachronic contexts? Why not noncomparative in both synchronic and diachronic contexts?

Why not comparative concepts in both synchronic and diachronic contexts? The portion of this question that is especially pressing is why not comparative in diachronic? One can put a point on this by saying that nothing seems to rule out, at least in thought, conceiving of the diachronically presented stimulus as not just light blue, but as a blue lighter than the blue on the Union Jack.

One sort of move the conceptualist can make at this point is to appeal to an independently motivated account of a mechanism that would serve to distinguish a perceptual deployment of a concept, in this case, light blue, from a deployment in an accompanying thought, in this case, lighter than the blue of the Union Jack. One might say that what's distinctive of perceptual deployments is that they are automatic and exogenous, and further, which concepts are automatically exogenously elicited by a stimulus reflects, in part, the learning history of the person (Mandik, 2006).

An additional move is to note that it wouldn't really be damaging to the conceptualist to allow comparative contents in the diachronic context, for there's no reason to believe that the comparative concepts would have much effect on the patterns of success and failure in the Old Experiment. So, to go back to questions along the lines of “Why can’t a subject apply a comparative concept in the diachronic case?” the advocate of the First Approximation may offer a response that will be along the lines of “They can, but these will just be guesses or flights of fancy with no real hope of being accurate.” So, suppose a comparative concept were deployed during the diachronic case. Which one? And, when? At time t1 the subject can make some wild guess prediction that the current color is darker than the one coming up next. But there’s no reason to suppose the existence of a reliable mechanism for deploying the right concept. That would be clairvoyance. At time t2 the subject can make some wild guess that the previous color was darker, but it is implausible to suppose there to be a memory trace of what was present at time t1 and thus the subject would be no more reliable about the past than the future.

I turn now to the second question that constitutes the problem of mechanism. Why not noncomparative concepts in both synchronic and diachronic contexts?

The portion of this question that is especially pressing is why not noncomparative concepts in synchronic contexts? Why not two noncomparative concepts, BLUE1 and BLUE2? On the face of it, the hypothesis that the subject possesses these two concepts is tantamount to the hypothesis that the subject possesses individual concepts (lexical, non-phrasal concepts) for each property the subject is able to perceptually discriminate. And the question needing consideration here can be considered as the question of what basis the conceptualist has for rejecting this hypothesis. It strikes me that the remarks made earlier about memory can serve as this basis. Noncontroversial examples of experienced colors we do have concepts for are such that, as a matter of empirical generalization, differently conceptualized colors are diachronically discriminable. It seems reasonable, and in keeping with empirical generalization (M) for the advocate of the First Approximation to deny the possession of fine-grained noncomparative concepts by subjects to whom the relevant colors are diachronically indiscriminable.

6.4. The problem of plausibility
The defender of the First Approximation needs to make it plausible that blue1 can seem different in the diachronic and synchronic contexts. Here the conceptualist can make a plausible case that such differences would be a species of already well known and widespread effects of context on color appearance. Context effects are well known in the literature on color perception.[10] In normal lighting conditions, one and the same paint chip may seem gray or bright yellow depending on what else is present in the visual field. Further, manipulations of context can make distinct chips look the same in color. Such context effects need not involve a difference in what light arrives at the eye from the paint chip in question. Nor are they explained by interactions between retinal cells. The perceptual effects of context depend on higher levels of the visual processing hierarchy than the retina.

It is open to the conceptualist, then, to offer as plausible that different conscious perceptions arise from the same chips presented in different contexts. Presenting a chip by itself on one occasion and with another chip on another occasion is to present the chip in two different contexts, contexts that give rise to differences in the perception of the color of one and the same chip.

6.5. The “New Experiment”
Where the first three problems seemed met by the First Approximation with relative ease, this fourth problem will show some real weaknesses.

We can view the New Experiment as designed to control for the sorts of context effects discussed above. The sort of redesign I here have in mind might go as follows. The stimuli presented in each distinct presentation in the diachronic discrimination case would be one of figures 1 and 2.

figure 1.

figure 2.

The task put to the subject is to make a “same as before, yes or no?” judgment about colors appearing on the right side of each display. Synchronic discrimination tasks could use just one of figures 1 and 2 and ask, say of figure 1, if the left and right regions contain the same color.
Such an experimental design is aimed at avoiding the accusation that the colors presented in the synchronic and diachronic contexts are colors presented in different color contexts and thus may not be assumed that there is a color appearance that is constant across contexts. In this new experiment, the color context of the right-hand color in figure 1 is arguably the same as the color context of the left-hand color in figure 2 since figures 1 and 2 are just spatial rotations of each other.

The New Experiment seems to pose a serious difficulty to the First Approximation. Recall what the core of the First Approximation’s explanation of the data in the Old Experiment is: blue1 and blue2 are synchronically but not diachronically distinguishable because the conscious experience of blue1 involves different concepts in the synchronic and diachronic contexts. But in the New Experiment, the synchronic and diachronic discrimination tasks do not involve presenting blue1 in different contexts, so the First Approximation’s central explanatory strategy looks to gain no purchase.

Now, I am optimistic that there is a version of conceptualism that will be able to handle the data from the New Experiment, but it looks like the explanatory strategy the First Approximation will not suffice.

[10] See (Lotto & Purves, 2002)