Wednesday, September 13, 2006

Black and Black

When I close my eyes, and I'm not looking toward a bright light, I'm tempted to say I see black -- or, more accurately, an assortment of colors (afterimages?) on a largely black background. (See this post for a broader discussion of what we experience when our eyes are closed.)

But here's something that shakes my confidence: When I put my hands over my eyes (without pressing), it seems to get considerably darker. When I then remove my hands, I'm inclined to think (a.) that I'm having pretty much the same visual experience as when I originally closed my eyes, and (b.) that experience is one of middle gray, or -- since that doesn't seem quite right, either -- at least something too bright to be black.

Now it seems to me that either I was wrong in my first judgment that I was seeing (largely) black, or I'm wrong in (a) or (b).

The fact that the experience gets blacker with the hands over the eyes does not, it seems to me, compel the conclusion that it wasn't black in the first instance. My jeans are black, but my desk is definitely quite a bit blacker. Does this necessarily imply that my jeans are really only gray? And my desk is shiny. It reflects the beige floor tiles, in places, in a way that really is rather bright. That doesn't seem incompatible with its also being a perceivably black object; but is my visual experience as I look at that patch of the black desk also a visual experience of blackness? -- not just an experience of a black object, but involving "black(-ish) phenomenology" itself? Hm! I worry that there's something objectionably simplistic in that question, though I can't quite put my finger on it.

Coming back to my visual experience with my eyes closed, some of these same questions and confusions arise.

But -- you might have thought -- what could be simpler than recognizing an experience of blackness? Aren't judgments about one's current visual phenomenology of a field of color exactly the kind of thing that many philosophers have thought it's impossible to be mistaken about?

7 comments:

Brad C said...

Hi Eric,

I have some (!) doubt that it is the same experience before and after. Consider, first, the simutaneous contrast effects (e.g. http://www.yorku.ca/eye/simcont2.htm). I have a painting that has grey, white and black squares (solid colors) but which looks shaded where the squares meet.

Next, consider the claim that many color-based sorieties paradoxes trade on a similar effect that occurs when we look at squares next to each other or in close temporal sequence. I seem to remember Williamson using that argument in his book on Vagueness, but am not sure where.

In any case, I think this could be tested empirically for color squares. I bet it has been tested....well, just a worry.

check this cool example out:

http://www.michaelbach.de/ot/
lum_dynsimcontrast/index.html

Tanasije Gjorgoski said...

Hi Eric,
I don't see a problem there.
We use "green" also to refer to all kinds of green.
The color expert can distinguish spring green and scarab green. And he can do that only because there is phenomenal difference based on which he can learn those colors.
What is needed to be distinguished is concreteness of the color seen, from the color as abstraction.
If you are interested, I wrote some time ago on my blog on this difference between concrete and abstract here.

Eric Schwitzgebel said...

Thanks for the links, Brad and Tanasije! That second demonstration Brad mentions is quite especially cool!

I agree completely that it could be black first and then not-black later, due to contrast effects, even if (say) the amount of light penetrating the eyelids is exactly the same. Maybe, indeed, that's the most likely possibility.

My suggestion that the experience in the first instant and the experience after removing the hands are the same is, however, not based on anything theoretical that would be undermined by Brad's and Tanasije's theoretical counterpoints above, but rather on my own subjective impression that the two experiences are the same. This is a subjective impression that I don't have about the gray dots in Brad's second luminance demonstration. So that's at least one reason to think something different is going on here.

My subjective impression of the sameness of the "before" and "after" experiences could be completely mistaken of course; but it's hard for me just to comfortably accept that without probing the other possibilities a little farther, too.

I find Tanasije's distinction between the concrete color and the color as an abstraction to be a useful one -- though it doesn't entirely settle my worries about the shiny desk -- this is no subtle difference in shading!

Jennifer M said...

I do not know what your theory of introspection is but some may explain the experience of the first 'light-blackness' as seeming black only because in that instance you apply a black-concept, or recognize it as falling into that category- in the process of introspecting. You may also apply the concept when you introspect after covering your eyes- despite the fact that the second experience differs qualitatively (different qualia). I'm not sure I'd advocate this myself- as it leans in the direction of a higher-order theory of introspection- though it could be that we introspect in different ways at different times, or that different people introspect differently. So maybe then in this case you introspect in a way that affects the content of the experience by adding something conceptual. Bome to think of it though, I don't see any reason why this explanation couldn't apply to what is going on pre-introspection...

Eric Schwitzgebel said...

Thanks for the comment, Jennifer! It's interesting to conjecture that maybe the application of the "black" concept affects the experience itself. I don't see why not -- but then also I wonder why we're tempted to apply that concept in the first place. Something pre-introspection, probably! And I agree with you here that something conceptual might be driving this -- e.g., an analogy between seeing something black and a lack of visual input...?

Jennifer M said...

I guess the problem for someone advocating a two-component explanation like this is to provide an account of how the sensory component gets hooked up with the conceptual component- you suggest a very interesting causal hypothesis- receiving no sensory input is like perceiving black (or probably the other way around)- and so the lack of visual input when your eyes are closed causes you to apply the black concept- did I get you right?

Eric Schwitzgebel said...

Yes, Jennifer, that's the thought. But I remain undecided on the extent to which the lack-of-input/black similarity is phenomenally or sensorily real, as opposed to a culturally contingent hypothesis or analogy!