Are colors causally effacious in non-conscious interactions?

Great Debates
21

Light exists as a continuous spectrum of wavelengths. “Color” is a function of the intensity values from three narrow frequency bands within the spectrum that correspond to the sensitivity of the three types of color receptors in the average human eye. You can build a mechanical detector that will look at the relative intensities in these three bands and print out the message “red”, “blue”, “yellow”, “pink” or whatever. No consciousness is required.

“Color” is defined by the properties of the human retina. But it doesn’t depend upon human consciousness to exist.

22

I don’t quite understand the question, and as a physicalist I think the colour realism debate is IMO rather a storm in a teacup (as that article indeed argues). Human visual cognition uses all kinds of mechanisms to arrive at the output “the colour I reckon that thing there is”, some of which can yield mutually exclusive outputs (such as in the clever creations you mentioned). Let us put these “optical illusions” (a phrase I might question in the course of the thread) to one side for the moment, to return to them later.

For now, let’s talk wavelengths. If EM radiation of 520-570 nm is incident on my retina, I will say “I can see the colour green”. Again, note that there are other ways to get me to say this which I’m not addressing yet. But in this specific experiment, this wavelength is directly causative: turn the wavelength on, I see green. Turn it off (again, let’s wait for the cells to return to their default state so I’m not merely seeing the ghost image from their decaying activity after switch-off), I don’t see green. In this instance, EM radiation of 520-570 nm is causing me to see green: it is not “coincidence” if it makes me see green every single time and makes the green disappear every time it is turned off.

Now, is this to say that the radiation is the colour green? I wouldn’t be particularly interested in mounting that semantic carousel, really. I’d suggest it’s perfectly useful shorthand, which only the most obtuse of pedants would object to, to say that those wavelengths are green (while acknowledging that there are other ways to get my visual cognitive modules to output “green” even when those wavelengths are absent).

So, sticking with the wavelengths, let us wander back through the timeline of evolution. Those wavelengths of 520-570 nm are useful to all kinds of organisms (and, again, many of them might also guess it was seeing those wavelengths when viewing other wavelengths in a clever experiment designed to target other aspects of visual cognition such as relative instensity as in the checkerboard). The premise has been set forth that bees are conscious, which I’ll accept for the time being, so let’s wander further back.

The wavelengths 520-570 nm are amongst the ones not used by an important chemical, so it reflects them instead of absorbing them, while other parts do absorb these wavelengths. So is the colour green anything to do with trees and their fruit, even when there’s nobody around? The leaves are still reflecting their 520-570 nm, so if I or a bee were to enter its vicinity on a sunny day, we would indeed see the colour green. Again, I would find it rather tiresome to debate the difference between “the trees are green” and “the trees cause me to see green” since we all understand what the former means.

So when those wavelengths from the leaf are absorbed by the fruit, is the “fruit seeing green”? The wavelengths in this case are involved in a simple chemical reaction, rather like if they were incident on the silver halide emulsion on the film in a camera (or the CMOS sensor in a digicam). But the same can be said about the retinal glial cells in my (or the bee’s) retina.

Why do we say that I can “see”, and the bee can “see”, but the fruit (or the earthworm, or Stevie Wonder) can’t? I’d suggest a definition based on consequences: Both I and the bee can carry out alternative actions based on the electrochemical signals from the cells those wavelengths were incident on being processed in working memory. The fruit, worm and Stevie cannot. And, of course, a camera could be attached to a robot, yielding an ability to act upon the wavelengths upon its sensors, and thus become as conscious as a bee (if such they are).

So, back to the question: is the colour green “causally efficacious” on the interaction between the sunlight, leaf and fruit? The 520-570 nm certainly cause chemical reactions in the cells of the fruit just as they do in the cells of my retina, or the bee’s, and I’d suggest that calling fruit conscious is bananas (OK, I know it’s really a herb).

And that’s why I don’t understand the question. It appears to define “consciousness” as being indispensable to “colour”, in which case there’s no such thing by definition as colour causation in a non-conscious interaction like the sunlight, leaf and fruit. A physical explanation of consciousness will necessarily make references to wavelengths. That does not mean that everything those wavelengths hit is conscious. (It sometimes amazes me that I have to make these kinds of points at all, but that’s philosophy for you I guess).

So finally, what about “optical illusions” like the checkerboard? Well, if our actions were based solely on the wavelengths and nothing else, we’d come a cropper pretty early on in our evolution since we would literally be jumping at shadows throughout our panic-stricken lives. Our visual cognitive modules are evolutionarily adapted to ignore shadow information so as to be better able to identify real threats. And it is that “ignoring” mechanism which leads to the strange differential output for the two identical wavelengths from each square. Interesting, certainly, but it doesn’t impugn the premise that the brain is a computer any more than a speed camera being foiled by a highly reflective license plate. And in the “green” flashing lights example, those 520-570 nm wavelengths just aren’t there. However, one simply could not say that the green lights were nothing to do with wavelengths, because the pink lights which are there are the “burnt in” inverted spectrum of the green lights. Again, just because I can cleverly be made to see the colour I usually get from 520-570 nm even when those wavelengths aren;t being reflected doesn’t mean that colour is nothing to do with wavelentghs - there is still a physical explanation of my seeing “green”.

So, if we wanted to design a computer which saw colour exactly like homo sapiens (although what the point of that endeavour would be escapes me), we’d have to include “shadow ignoring” subprocesses and use light sensors which produce afterimages like the cones in our retina, so that the computer made the same “mistakes” as us.

23

The thing I like about you, Sentient, is that you know how to kick a party into high gear. You’re the philosophical equivalent of the guy that brings the beer.

Here is where I’d ask you the same question I asked ll Gyan ll: What is the cutoff point for having consciousness or not having consciousness?

The fruit or worm might well carry out “alternative actions” depending on the relative moisture or temperature of their environment, the stage of development in their life cycle, etc.

In other words, “alternative actions” might simply be more complex “alternative re-actions”, in which case, the “actions and consequences” of bees and humans could also be merely reactions: equivalent to the fruit’s only much more complex. Consciousness then becomes entirely superfluous.

Also, having consciousness hinge on an ability to act seems a bit shaky… if I was injected with a paralytic or otherwise immobilized, I would still be conscious.

24

How kind! But note that it is often that same guy who ends up puking on someone’s sister.

My suggestion is that the basis of consciousness is the processing of sensory input in working memory. So if something hasn’t got “memory” (like the fruit or earthworm), or if that memory is static, ie. not working as such (like a cliff face or corpse), then consciousness is foiled. Stevie Wonder has visual memories to be reactivated (as well as other senses still incoming). And the bee has among the simplest examples of what I’d call working memory in which processing occurs in order to yield one of a range of actions, as opposed to the singular inevitability of the thermostat or amoeba.

Now of course, you can reject this suggestion of mine at the drop of a hat, but note that definitions for all kinds of things are ultimately as debatable. I prefer Francisco Varela’s definition of life while others reject it, but that does not impugn the physical explanation for life.

Again, these cannot be said to be acts of computation or correlation as in the bee’s case. I consider that correlation with past memories yielding outputs above or below a given threshold (which can be affected by noise) is the basis of “acting upon one’s senses” (I haven’t yet read Dennett’s Freedom Evolves, but it’s on my long, long list).

Agreed: it would be a threshold we used to label things. Guess what? All words are like this. Language is a scheme whereby we arbitrate things into sets labelled by a sound or sequence of shapes. We might have different thresholds for which gets labelled what. That phenomenon itself is called “disagreement”.

Only as superfluous as saying that 550nm looks “green” while 700 nm looks “red”. Why quantize the continuum of the EM spectrum so arbitrarily?

Well, I was talking specifically about seeing in order to answer the question “why do we (including you, presumably) say that I and the bee can see but Stevie and fruit can’t?”. We say that because the former entities demonstrably act (or not) upon that configuration of wavelengths while the latter don’t: show Stevie or the fruit a photo of a flower and there is no difference in their behaviour. And in your vegetative state, there are various tests used by medical personnel to establish whether any potential to ever ‘act’ again, or whether you are “brain dead”, and thus able only to absorb or reflect wavelengths like the fruit.

So, here I am making some suggestions, like I do for the definition of life. Reject them or accept them as you will - I can’t really say I’m much bothered either way (although convincing someone else is always a nice achievement). What I definitely will steer clear of here is endlessly supplying definition upon definition in support of those general suggestions (which don’t really matter anyway: the explanations are the important things). I’ll also insist upon only answering questions in return for explicitly hearing my questioner actually take a position on something I ask about in order to identify the crucial point upon which we might disagree - I’ve wasted too much time in trying to ascertain the position of others only to find they didn’t have any except a desire not to have mine. Hope you understand.

25

I think we agree, for the purposes of this discussion, that a piece of fruit, an earthworm and a human all can be said to acquire “sensory input”, although to different degrees and through different modalities.

So whether something is conscious or not seems to hinge on whether that input is processed in working memory.

From the rest of your post I get the impression that labels like “computation”, “processing”, and the “working” in “working memory”, are in the eye of the beholder; whether a given sequence of events can be considered “processing”, or a memory-record “working”, depends on whether you say po-tay-to, or po-tah-to. Labeling something as a “computation” is tantamount to saying: “Hey, it works for me as a computation, so I’m going to suggest we label it “computation”, but YMMV.”

In short, you seem to be saying that determining whether or not something is conscious is more a matter of preference than knowledge (not that I disagree). Is this your stance?

Again, for clarification, I understand that these entities demonstrably act to the satisfaction of your explanatory criteria, but it is also your stance that one’s “explanatory criteria” is an inherently arbitrary call, yes?

Which brings me to…

If my characterization of your stance is correct (and if it’s not, by all means, set me straight), I’m somewhat baffled by your insistence that I cleave to one position when all positions are inherently arbitrary. If the playing field is level, does it really matter where I stand?

For what it’s worth, I’m taking the position that there is currently no reasonable way to determine whether or not a given example of information processing is accompanied by (or gives rise to, or is the result of,) consciousness. Hence, the OP’s question can only be answered tentatively and/or arbitrarily; not definitively.

26

To go back to the evolutionary angle, I’d say there is a physical basis for the color green.

Human’s tend to segregate colors based on a physically hard-wired breakpoints, otherwise we’d see a rainbow as a continuous spectrum, rather than several bands. There are some cultural factors in play here, but it’s hard to argue that with 3 (or 4 or 5 depending on what you count,) distinct receptors, that our observations are not quantized to a degree.

It is likely that our conceptualization of “green” comes from the grouping that evolved in order to recognize plants. Therefore, the property “green” is valid just as surely as the property “star” is valid. In my opinion, not much, as I don’t think any properties at all achieve ontological rigor, but it would be silly to let “warm” or “hot” be a property and not “green”.

27

What if there’s an illusion where that range doesn’t correspond to green, as in the checkerboard example.

You miss the point which is whether the colours are out there or a (almost) consistently covariant representation of the mind. I don’t think anyone’s claimed that wavelengths have nothing to do with color.

No, it asserts that it appears to be the case. You can show otherwise.

And that’s the crux. With shapes we don’t need to refer to other proxies. With colors and aural timbre, we have to switch the elements we talk about, exposing a duality. The reason for that is what this question’s about. It’s not a semantic carousel.

28

Yeah you do: the medium which they are imprinted on. There’s no such thing as a perfectly thin line: that’s a construction of consciousness, too. If you’re pointing at something and calling it a sphere, it’s not really a sphere, but your mind tells you it is.

29

From the OP:

One reason that seems to be is because shapes interact with, and hence constrained by, each other, so the only way to be a skeptic there is if one’s a skeptic about representationism in general.

I’m actually an idealist so I agree with your conclusion. But in this thread, I’m playing a folk physicalist:

assuming the commonsense framework that consciousness is a veridical naive representation of the physical environment with some detectable anomalies(i.e. illusions), colors still seem bereft of a place in the framework of physicalism.

30

In that case, I disagree. They seem bereft to the same extent that other conscious constructions seem bereft.

31

Here’s why not: Color is a surface property. In order for it to be causally efficacious among non-conscious entities, the transaction must involve communication about surface properties among the parties. But surfaces are a perceptual entity. Per folk physicalism, what exists in ‘space’ is matter-energy at various positions and the fundamental forces that apply. Their grouping and differentiation into objects based on sharp divergences is a conscious activity.

32

I don’t understand what you are saying about folk physicalism. How is color different from other observable properties? Hearing and motion and temperature sense can be deceived in the same way as vision, both through physical and perceptual illusions.

When light from the sun hits a plant, it communicates information about the surface properties of the sun. Namely, that the farthest out part of the Sun that generates light and is not obscured by other parts is releasing light of a wavelength suitable for photosynthesis.

Light also involves communication of wavelengths when a certain molecule can successfully absorb certain wavelengths and not others.

Now, certainly, what molecules and plants and humans “do” with this information may or may not be fundamentally different, but I don’t see how, according to a physicalist perspective, we are interacting differently with regards to simple communication of information.

I still don’t see why this should be true of objects and not light. I agree with the purported first sentence of their beliefs (i.e. lack of evidence for the existence of anything but matter-energy). I disagree with their viewpoint when you say that you believe they differentiate objects based on sharp divergences. I don’t assign ontological status to anything other than the universe. Everything else is just information interacting with other information, with varying degrees of definiteness, cohesion, and predictability.

33

We assign a quale, which is color, to the information, which plants don’t do.

How do you know where the keyboard ends and the desk begins?

34

Ahhhh, qualia. I don’t believe in it. Next question.

35

Yes. Indeed, my stance is that there’s no such thing as absolute knowledge - the ‘k’ word is just shorthand for very very strong belief, since there’s a possibility that we don’t “know” anything at all. Even by using the word “unconscious”, “dead” or “green” you demonstrate your position that some things are “conscious”, “living” or “red”. I propose that your threshold for these things is as much a matter of preference as mine.

Yes, or at least as arbitrary as calling 550 nm “green” but 700 nm “red”, like you do so so arbitrarily.

For useful dialogue, yes. Our choice of English here is inherently arbitrary. That’s not to say that it wouldn’t matter if you started jabbering away in Flemmish or I in Welsh. As the Monty Python sketch says, “An argument is a connected series of statements intended to establish a proposition … Argument is an intellectual process. Contradiction is just the automatic gainsaying of any statement the other person makes.” I have to find what statements you are prepared to agree with in order to find the precise point at which we diverge - that is what a Great Debate is, and has been since Socrates.

Well, that’s rather a leap from us talking about colour - perhaps another thread might be in order? In that thread, I’d ask you whether there was any reasonable way to determine if I’m conscious (by, say, asking me or something), or whether solipsism is the position you arbitrarily take.

Again, I would argue there’s no such thing as a truly ‘definitive’ answer.

36

I think you mean the flashing lights example? The shadow-ignoring visual cognitive mechanism doesn’t make me see green in either check, it makes one look darker than the other. In the flashing lights, as I say, even though 520-570 nm isn’t there, guess what is: the complementary wavelengths, such that the signal sent down the optic nerve, chiasm and tract is the same as if 520-570 nm had been incident on the retinal glial cells. This is explained, like other ‘ghost’ images, by the non-zero relaxation time of the cells themselves: consider a sensor whose needle pointed at the incident wavelength. When the light was turned off, the needle would oscillate slightly before returning to the zero default.

OK, I claim that wavelengths ultimately have everything to do with colour, in that there is a physical explanation for why certain wavelengths yield “the colour I say that thing there is” even if they aren’t present. I’ve explained the ‘pure’ case (which I’d like you to address in a moment, if you’d be so kind), and the checkerboard case, and the pink flashing lights case, and could explain the neon colour spreading case as well if you like. If you find them unsatisfactory, well, there’s no pleasing some people.

OK. The fruit absorbs the colour green while the leaves reflect it, because the primary causal mechanism of green in green-seers is those green wavelengths. QED.

Yes we do, still.

We dualise all over the place (for example, by using the very words “green” and “red”, as I’d like you to explore with me in a moment). Of course we’ll use different words for visual-range EM radiation (colour) to audible-range longitudinal vibration (timbre) to configuration of visible wavelengths (shape).

Hmm, I have my doubts. Perhaps you can help allay them with me …

I’d like to discuss with you the very simplest of colour perception experiments, to see just how or where we disagree. I know you might be keen to explore colour in “optical illusions”, hallucinations or dreams (ie. visual memories and their permutation) and the like, but if we could just leave them aside for the moment I promise to return to them later.

Consider a simple prism splitting white light. It’s bright light and a large prism, so I can position you such that you can only see a very tiny fraction of the angle across which the light is spread, ie. Wavelengths of a very small range - down to the nearest nanometre, say (entirely possible using a sensitive collimator, of course). So, by rotating the prism, I am changing only the wavelength of the light and leaving everything else equal. Let’s say I showed you 550 nm, and then 700 nm. Now, of course, the spectrum is a continuum.

I’d like you, Gyan, to tell me how you explain your calling 550 nm “green” and 700 nm “red”.

I realise I’ve asked a rather vague favour of you here which is counter to your usual modus operandi, but I assure you I’m just trying to find out as effectively as possible where we might disagree on this subject. If I can beg you please not to simply reel off a single sentence, but try as best you can to put together a couple of paragraphs as I always try to do for you. You might think your one-liners are as instructive as zen koans, but I rather think they’re as obstructive as traffic cones.

(I also beg your forgiveness for that terrible pun :).)

37

Well, Sentient, if all is arbitrary, it seems to me that the precise point where two positions diverge will always come down to po-tay-to vs. po-tah-to; and I don’t see how that conclusion is particularly useful since it’s what’s driving the debate in the first place. I mean, when you, Sentient, find the precise point at which someone’s position diverges from your own, you’ve gained… what? (Not trying to be snarky; I’m genuinely trying to understand your viewpoint.)

Also, I have a bit of a problem with the self-negation inherent in statements like “there’s no such thing as a truly ‘definitive’ answer”.

I’m going to try and answer the question you asked ll Gyan ll by disagreeing precisely and explicitly; let me know if that’s the kind of input you’re looking for:

I don’t call 550nm “green” and 700nm “red”. I call prism-light “red” or “green”, and I call the readings displayed on a spectroradiometer “nanometers”. I do not, nor have I ever, seen nanometers; I see red and green. “550nm” is not identical to “green” anymore than Star Wars is identical to a long, thin, strip of silver gelatin on a polyester base.

38

The location at which to work to effect a change of their mind - like I said, it’s always nice to convince another of the validity or veracity of your position, to “spread your memes” as it were. So many philosophy threads here and elsewhere are made inane and tedious by people’s reluctance to actually say what they think. Whither the cut and thrust of debate if one is too cowardly to even enter the arena?

Don’t misquote me. I said I would argue there’s no such thing as a truly ‘definitve’ answer. That admits the possibility that I might be wrong and there actually is such a thing - hence the statement doesn’t negate itself. (In fact, I’d hope you’d realise that everything I said had such a qualifying precursor, even if I didn’t make it explicit: I might always be wrong, even in that very sentence since I suppose it’s possible that I am always right!)

Apologies (and also to Gyan), my wording was sloppy.

Correction: I would like you, Gyan and other-wise, to explain why you call *light of wavelength * 550 nm “green” and *light of wavelength * 700 nm “red”.

39

Damn… I understand what you’re saying, but it still looks to me like you’re trying to have your cake, and eat it too: i.e., you’re trying to convince someone of the veracity of your position while maintaining that no position conforms to fact; a position can only to conform to belief.

I apologize; it was not my intention to misquote you. Since the statement was in response to my argument, I read the sentence as: “ Well, that would be your argument, but this would be mine…”. An understandable mistake, I would think, given that in the same post you stated flatly: “Yes. Indeed, my stance is that there’s no such thing as absolute knowledge.”

However, after your clarification your statement becomes: “There may or may not be any such thing as a truly ‘definitive’ answer”, which doesn’t seem to meet your own insisted-upon criteria that participants take a position on something they’ve been asked about while contradicting your previous claim that there’s no such thing as absolute knowledge.

Corrected Answer: I don’t call light of wavelength 550nm “green” and 700nm “red”. I call some of the electromagnetic radiation detected by spectroradiometer “light”, and I call the readings displayed on a spectroradiometer “nanometers”. I do not, nor have I ever, seen wavelengths or nanometers; I see red and green. “Light of wavelength 550nm” is not identical to “green” anymore than Star Wars is identical to a long, thin, strip of silver gelatin on a polyester base.

40

My position is that “facts” are strong beliefs (or, at least, that the phrase “it is a fact that…” is shorthand for “I and many others strongly believe that…”)

The position I take is that there is no such thing as a ‘definitve’ answer. This is different from an outright claim that there is no such thing as a ‘definitive’ answer.

If I shone 550nm light at you, you’d say “that light’s green”.

I didn’t say “identical to”. I said you call it green (and you do - don’t be silly). Why?