Talk:Inverted spectrum

Controversy Section
Not a regular wiki contributor but I stumbled on this page. The controversy section doesn't have any citations and reads like it was written by someone with an axe to grind. The central point is also broached in the main article I.e. the thought experiment is precluded by a full scientific understanding of colour perception. There seems to be some good points in there but I would suggest incorporating them into the main text (with citations) rather than a separate section. Right now it reads like someone scoffing at silly philosophers while they stand above them, proudly holding aloft the glorious torch of hard science. Just saying like.

- Chris — Preceding unsigned comment added by 86.150.42.22 (talk) 06:43, 25 March 2016 (UTC)


 * I'm inclined to agree, and I've tagged the offending material for clarification. RunasSudo (talk) 10:58, 5 June 2016 (UTC)

Introverted Spectrum
I think that this article can be improved significantly by identifying studies that were conducted on the introverted spectrum. In addition to this, I think that you could elaborate on what introverted spectrum consists of. — Preceding unsigned comment added by Lilroses2 (talk • contribs) 23:26, 26 September 2013 (UTC)

Anglocentric argument?
"Dark yellow is brown (qualitatively different from yellow), whereas dark blue is blue"

Is it true that "dark blue is blue" among speakers of languages other than English? Dark blue is Navy blue; light blue is azure. --Damian Yerrick (serious | business) 17:28, 21 November 2007 (UTC)
 * It Russian there are different words for light blue and dark blue.--MathFacts (talk) 21:16, 25 June 2009 (UTC)

The existance of inverted spectrum
Does the existence of color blind people not convince us that "inverted spectrum" is possible? I think the article can be a little more explicit about how exactly the claim of its existence is contested.

Musically ut (talk) 06:39, 25 November 2007 (UTC)


 * Not to mention tetяachromats. --Damian Yerrick (talk | stalk) 16:01, 25 November 2007 (UTC)

Speaking of colorblind people, couldn't the picture of the strawberry be replaced by a banana? I'm colorblind and see no difference between the left and right strawberry (red and green). Most colorblind people would have no trouble distinguishing yellow and blue. Han van der Heide 21:44, 30 Oktober 2011 UTC — Preceding unsigned comment added by 87.211.115.30 (talk)


 * A counter-argument runs thus: Colour is not perceived in a one-dimensional spectrum, but in Munsell colour system. Moreover, it is known that this shape is not symmetric. We are able to make finer distinctions of shades of yellow, red and green than of blue. It is conceivable that this shape could be "rotated" to be an inversion, but it would necessarily be detectable, because a person with a "rotated" colour space would be abnormally good at differentiating hues of blue, whereas she would perceive colours that others call different shades of red as the same shade. Also, the boundaries between, say, blue and green, or yellow and brown, would then be in different places, because some colours have larger shares of the space than others. So she would not distinguish two totally different colours for white and yellow. This last bit is what was meant by the "dark yellow is brown" stuff. This experimental psychological assignment of colours to a 3D-space is supported by neurological findings, because the neurons in the lateral geniculate nucleus receive stimuli from the cone cells, and react to them in a fashion which is exactly corresponding to the colour space. I won't go into it here (because I haven't got the book source here), but a plausible explanation of colour blindness and a range of other colour-associated visual sensory phenomena can be easily derived from this argument.


 * As an aside, the sense of "possible" required for the argument to work is a very weak one. Just because I can imagine that there i a place on the Earth where there is no gravity means (in this sense of possible) that it is possible. It does not mean that science has to seriously consider the possibility of such a place.


 * See Churchland, P. S. (2002) Brain-Wise: Studies in Neurophilosophy. Cambridge: MIT Press;
 * Lehky, S. R. and Lejnowski, T. J. (1999) Seeing White: Qualia in the Context of Decoding Population Codes. Neuronal Computation 11, 1261-80; and
 * Palmer, S. E. (1999) Vision Science: Photons to Phenomenology. Cambridge: MIT Press.


 * Hinakana (talk) 10:12, 29 July 2008 (UTC)


 * I would like to point out that physical consideration breaks that sort of argument. The properties mentioned are all related to the physical properties of the neurons that detect light and the overlaping of spectra detected. Unfortunately the argument is flawed be the fact that it mentions inversion of the spectrum. That means that colors would become their spectral opposite or in other words each cone would map to the combination of the remaining two cones; when broken down into color components it makes much more sense that each type of cone would have an independent qualia, making the translation take on a number of extraneous quirks. If, however, one considered that a switch took place between two or all three of the color-receptive channels such that reds resembled blues or otherwise the color-space would not change. A few things are notable in that case: the new color where green once was would be brighter because of the rod cells; the new blue would be just as difficult to distinguish because the S type cone (blue) will be no more perceptive to minute changes in light intensity; no color information would be lost or gained it would only have a different perception associated with it. This still does not prove that qualia exist nor don't exist. It could simply be that the experience of color is simply the addition of different amounts of mental aliases of color components, thus making the inversion of colors analogous to calling the number one by the name two. Two plus two would then be one but the numbers didn't change their properties so the difference is only lexical. Thatoneguy (talk) 06:32, 21 November 2008 (UTC)

Inverted spectrum arguments aren't particularly meant to be 'taken seriously by science'. Many philosophers believe that possibility conceivability is enought to establish their case. 1Z (talk) 17:18, 29 July 2008 (UTC)


 * Fascinating; I had no idea that this idea is so old: this exact scenario bothered me a lot when I was a teenager. Is it possible that other people perceive colours radically differently from me? Apart from not being able to differentiate some of them at all, as in colour-blind people, of course. The decisive argument to me at the time was that the primary colours are not really exchangeable: pure green is inherently brighter than pure red, which in turn is inherently brighter than blue, while green is not nearly as bright as white and blue not nearly as dark as black. Only a fully inverted spectrum remains a possibility given this consideration. But is it conceivable that the spectrum is inverted for others? What settled it for me is that black and white are asymmetric in their properties, as well: a blindingly bright black and a deep dark white representing complete darkness struck me as absurd, also because to me, darkness is associated with pronounced visual snow, like TV noise, and it always reminds me of those infrared night vision devices, which, judging from TV images, also produce pronounced noise.
 * However, it seems that that is a peculiar property of my individual perception again, even though it made sense to me back then (and still does), considering that it cannot be expected that this huge number of retina cells will always work perfectly and send the exact same shade back to the brain (and the nerves may not work this perfectly, either, and keep firing randomly instead, to some extent), and small deviances are bound to result in such visual snow, while the statistical averaging out still furnishes the darkness I intuitively understand is really there. It seems that other people just automatically filter this snow out – only my brain somehow doesn't.
 * In any case, that line of reasoning calmed me at the time, and I still think that people who perceive certain colours at all, perceive them basically alike, though not everyone may perceive them in an equally fine-grained manner, whether because of biological or cultural reasons; but it is true that the possibility of the scenario described in the article seems hard to exclude. --Florian Blaschke (talk) 09:43, 20 November 2011 (UTC)

Physically Nonsensical
It should be stated that the argument is a physical impossibility, due to the nature of electromagnetic frequency. —Preceding unsigned comment added by SpunkySkunk347 (talk • contribs) 07:27, 21 March 2009 (UTC)
 * Another way to state the argument: Are the signals from cones sensitive to long, medium, and short wavelengths carried on the same "pins" of the optic nerve in everyone's brain? If I were to swap the red and blue "wires", how much would qualitative experiences differ? --Damian Yerrick (talk | stalk) 17:12, 22 March 2009 (UTC)
 * Imagine that you performed this massively complex brain surgery. Firstly, you can't actually swap the red or blue wires without taking, respectively the green and yellow ones with (see colour oponency).  Now red/green is blue/yellow, the relations between red and green and between red/green-blue/yellow and blue-yellow are in a sense, 'switched' (an actual inversion would be impossible).  All the proporties previously pinned to blue-yellow cells now apply to green/red cells, these proporties are different and would result in a massive differences detectable in the same way colour-blindness is (e.g. some aspects of depth perception).  So to answer your question yes the signals are carried on the same "pins".Talonx84.152.181.136 (talk) 15:58, 3 July 2009 (UTC)
 * I imagine swapping the wires in someone's brain is a "physical change in brain or body", so this must be some other argument. — Preceding unsigned comment added by 83.27.249.158 (talk) 21:50, 23 March 2012 (UTC)

If it is conceivable, then it is possible
I smell an equivocation of the word "possible" in premise 4: "If it is conceivable, then it is possible." Premise 5 appears to use "possible" in the sense of "physically possible"; otherwise, the whole argument is a tautology. This would make premise 4 false because some things that are conceivable are physically impossible. --Damian Yerrick (talk | stalk) 17:20, 22 March 2009 (UTC)

Inconceivable
Seeing as the average person has absolutely no idea what physical changes would cause an inverted spectrum, it is impossible to imagine. Human imagination is not prepared to imagine what we cannot piece together from experience. We can no more envision brain chemistry than we can imagine a penteract. 75.118.170.35 (talk) 22:12, 22 June 2009 (UTC)
 * Try this: A mutation similar to those for color blindness swaps the pigments in the red and green cone cells. So the green sensors are "wired" to red, and the red sensors are "wired" to green. So the argument becomes the following: "Because prot- and deuteranomaly exist, qualia exist." --Damian Yerrick (talk | stalk) 19:37, 26 June 2009 (UTC)
 * It doesn't work that way, the signal a cone cell put's out is actually dependent on the protein's absorption of light, the cells themselves are identical otherwise. If, however it were possible, the person would likely simply be blind as the proper signals would not reach the proper assemblies of cells for colour perception, those cells would atrophy.Talonx84.152.181.136 (talk) 16:06, 3 July 2009 (UTC)
 * So if the S, M, and L cone cells send qualitatively different kinds of signals, your expertise in explaining these details of color vision would be appreciated. So can we use the analogy of R-Y and B-Y in a YPbPr component connection? --Damian Yerrick (talk | stalk) 01:01, 10 March 2010 (UTC)

Illustration
If you look at the picture with the strawberries in the smallest version (320 x 184 pixels), you can easily view it as an autostereogram ("Magic Eye"). The strawberry seems to flash red and green alternately. This is of no help to understanding color perception, but it is pretty cool. Kejo13 (talk) 04:08, 1 July 2013 (UTC)

"Supporters of the existence of qualia" or "supporters of the immateriality of qualia"?
"Qualia" isn't a very consistently defined concept, one of the definitions, AFAIK, is just "subjective experience", "the way things look", contrasted to the physical stimuli or the resulting neural activity pattern ("neural correlate"). In other words, the non-inverted spectrum would already be qualia, and therefore it's nonsensical to "not exist". Also, supporters of a physical basis don't need to accept a 1:1 correspondence of external physical stimulus and quale. It's only required that the ultimate neuronal activity/synaptic correspondence would be constant, but there's room for developing individual variation in response to stimuli (which is perhaps exemplified by the Himba people and other cases of shifts in the range of color discrimination without anomalies in photoreceptors or in the brain).--Extremophile (talk) 04:33, 16 January 2014 (UTC)

Counter example to Douglas Hofstadter's?
Depending of one's premises, the "absurd" of inverted spectrum could be just as "absurd" as one language having an "inverted vocabulary" in comparison to another language; or, to something without the etymological-historical improbability, different languages actually existing at all, with different words for the same things in the world outside. It's not a matter of "concepts", but "percepts"; the phenomenal "redness" isn't necessarily intrinsically, meaningfully linked with the light frequency (that's nothing but naive realism, even though it's hardly disputably inherently linked with a neural correlate), unlike the concept of tyranny and its very definition -- but not so much the sound of the word itself, there are plenty of examples of false cognates. I don't know of any succinct counter-argument to that, but perhaps Edmond Wright's "The defence of qualia" may have. I'll take a look someday. --Extremophile (talk) 05:11, 16 January 2014 (UTC)