Occurrent memory of color experience

Many people when occurrently remembering what a tomato looks like have a mental image, with a degree of vividness and precision differing from person to person, of a red round thing. But not everyone. Visual aphantasiacs don’t have visual images at all in their memories. Presumably, too, there are partial cases: some may have visual images of shapes but without color. Nonetheless, it seems correct to say that such people still know what red is like.

I conjecture that most people have some kinds of experience where they know what the experience is like, but when they remember what the experience is like their memory does not contain a phenomenal copy of the experience. Maybe for you it’s certain kinds of tastes, or smells, or feeling hot water on your body.

For definiteness, suppose that for Alice it’s redness. She has seen red tomatoes. She knows what it’s like to see red, and she remembers what a red tomato looks like, but when she makes her memory occurrent, it does not contain a phenomenal copy of the experience.

What’s going on? Here is one possibility. Even though the memory of a colored object has no visualized color in it, it has some other distinctive phenomenal quality that encodes the specific color. Thus, while neither remembering a red tomato nor a blue plum involves visualizing a color, remembering a red tomato involves a non-color phenomenal quality that encodes the redness, while remembering a blue plum involves a different non-color phenomenal quality that encodes the blueness. It is by having that encoding non-color quale that one knows what the encoded color quale is. The encoding non-color quale is presumably not a sound, or a smell, or any other sensory quale, but a distinctive memory-of-color quale.

(One might conjecture that this is so even for those aphantasiacs who deny any phenomenal quality to their memories, because perhaps it is possible to mistake not having sensory qualia in one’s memories for not having any qualia in them.)

(One might also wonder if it goes to meta levels. If you remember remembering a red tomato, do you have a memory-of-memory-of-red quale, rather than just a memory-of-red quale? I don’t think it needs to do that. If you’re capable of having a memory-of-red quale, that can just figure in your memory of remembering.)

It seems very plausible that on this suggestion, the memory-of-X qualia can differ from person to person, even if the X qualia do not. One reason to think this is that some people do visualize colors, and for them a memory-of-red quale will just be a red quale (or a visualized-red quale, which might not be exactly the same). But a more interesting question is this: Can two people be such that one person’s memory-of-X quale is just like the other person’s memory-of-Y quale? The answer could be negative even if the memory-of-X qualia differ from person to person, for it could be that nonetheless there is a person-independent way to recover the X quale from its encoding in the memory-of-X quale. There can be multiple ways of encoding the same thing while yet each one can be uniquely decoded.

Maybe. But what if it turns out that there is no person-independent mapping from a memory-of-X quale to an X quale? I think this endangers the idea that having a memory-of-red quale in conjunction with one’s remembering is what makes one count as occurrently knowing what a ripe tomato looks like.

Is there a different way to account for what happens when one occurrently remembers what it’s like to see a red tomato when one cannot visualize colors, without positing some kind of memory-of-X qualia?

Here’s a suggestion inspired by David Bernhardt’s comment (but perhaps with I misunderstood the comment). Our thoughts can make de re reference to objects and events and the like. Perhaps when I think “Ripe tomatoes look like this”, the “this” makes a de re reference to my past experience of red. But just as the word “this” does not reflect the specific character of its referent, and indeed sounds and looks the same regardless of what it refers to, neither do the intrinsic features of the thought reflect the specific character of the past experience of red. Imagine you’re an almost exact twin of mine, except that you always wore glasses that swapped red and blue. Then you could have an intrinsically exactly similar “Ripe tomatoes look like this” thought to mine, but in your case the “this” would refer to an experience of blue.

Could something like this be how we have occurrent memories of how tomatoes look, a mere demonstrative de re thought? If so, then the knowledge argument against materialism is in trouble. For Mary, raised in her black and white room, could have a de re thought that ripe tomatoes look like this, where her “this” refers de re not to her own experience but to mine! After all, if you and I are both pointing to the same horse, and you think “This animal is lovely” and I think “This animal is lovely”, we seem to be thinking the same thought, precisely because our “This” has the same referent. So if Mary thinks “Tomatoes look like this” and I think “Tomatoes look like this”, and the “this” in both cases refers to my experience of red, then we seem to be thinking the same thing.

This suggests to me that we have three options:

1. People who can’t visualize colors don’t know what colors are like when they aren’t currently perceiving colored things.

2. They know it by means of memory-of-color qualia, which have an unambiguous mapping onto color qualia.

3. They know by means of de re thoughts that get their content from past experiences that are not reflected in the intrinsic character of the thought.

I think (1) and (2) leave the knowledge argument against materialism in place, but (3) endangers the argument.

I don’t know what the right story is.