13 Abstraction and indeterminacy
The purpose of this section is to argue that the 6% difference between the attended 22% and unattended 28% patches underestimates the effect of attention. The reader who is willing to take that on faith can skip to the conclusion.
I argued that since the attended 22% and unattended 28% patches look the same when seen in peripheral vision but look determinately different from one another when seen foveally and attentively, we can conclude that the precision of the phenomenal and therefore representational content of the attended foveal percepts must be greater than that of the prior percepts—if representationism is true and all the mentioned percepts are veridical. The reader may not be convinced however that the 22% and 28% patches do look determinately different when seen foveally and attentively. Perhaps the sense that they look different is a matter of an ability to discriminate rather than an appreciation of appearances that are determinately different.
The Carrasco lab experiments reported so far use stimuli that are 4o from the fixation point. But you might have noticed that when you fixated the bottom left square in Figure 9, you could also see the 28% patch to the far right. And some of the Carrasco lab’s experiments have been done with 9o angle of separation.
Figure 15: If you fixate at the “+” sign and attend to the left patch, it should look approximately equal in contrast to the right patch. My thanks to Jared Abrams for help in constructing this figure.
If one combines the two different angles of separation as in Figure 15 an attended 16% patch looks the same in contrast as an unattended 28% patch, a larger difference than mentioned earlier for this absolute level of contrast. (The differences produced by attention increase with absolute level.) Of course the logic of the case is the same as before. I introduce it because I think it is easier to be sure that the patches in Figure 15 look determinately different when foveated and attended.
Of course there is a difference between the relations between the perceiver and the two patches—in the different angles of separation from the fixation point. Does that ruin the case for my purposes? Note that there was a difference in the relations between the perceiver and the two patches in the experiments of Figure 6 and Figure 7, namely one was on the left of fixation and the other was on the right. Why would there be a difference in relevance between left/right and number of degrees of peripherality?
Recall that imprecise contents were introduced in the first place via the following reasoning. An attended 22% patch looks the same as an unattended 28% patch. But both percepts with that same contrast phenomenology are veridical. In order for percepts with that phenomenology of contrast to be grounded in the representation of contrast, the imprecision of the representational content has to be at a minimum 22%-28% (inclusive of 22% and 28%). Suppose the representationist had said “No no, those phenomenologies are different since one is leftish and one is rightish so there can be no legitimate demand for a representational content in virtue of which they have the same phenomenology. That argument would look silly and be silly because we have an appreciation of how contrast looks independently of which side it is on. We can easily abstract the percept of contrast from a total percept of contrast on the left or contrast on the right. The sense of ‘abstract’ here is a question of appreciation of the phenomenology of contrast independently of perceived location: I speak of abstraction because location is abstracted away from.”
I suggest that the same reasoning applies to Figure 15 even though the difference in peripherality is causally implicated in producing the apparent contrast. The point is that we have an appreciation of that contrasty look independently of degree of peripherality and can appreciate that the two patches look the same in contrast when I am attending to the one on the left. The point is that a 16% patch can look the same in contrast as a 28% patch with the right distribution of attention and we need a representational account of what it is in virtue of which these apparent contrasts are the same. And with respect to that issue there is nothing illicit about comparing 4o with 9o.
The issue of abstraction I just mentioned comes up often in discussions of problem cases for representationism. Consider the phenomenal difference in seeing the round rim of a drinking glass and feeling it with one’s hand. Both are percepts of one property, circularity, but the phenomenology is different. How can representationists cope with this case? Michael Tye (1995, p. 157; 2000, p. 93-95) has noted that the “total” percepts involve representation of different properties. These “collateral” properties might be shininess for the visual percept of the circularity and temperature for the tactile experience. The difference between the percepts can be blamed on the perceptions of these different properties. That is, what we are visually representing is circularity-&-shininess and what one is tactually representing is circularity-&-coldness. Can one abstract the visual impression of circularity from the total visual percept? Can one abstract the tactile impression of circularity from the total tactile percept? Tye says he cannot make sense of such abstraction. However, our ability to abstract shape from location on the right vs the left suggests the Principle of Spatial Abstraction: perceptual placing of a feature at a location can be abstracted from the perception of the location. I have a visual appreciation of the color of an object even as it moves, changing location. To the extent that this principle is accepted it licenses the use of Figure 15 in the premise that the contrast percepts are determinately different.