Talk:Color vision
From Academic Kids
There is really no such thing as color vision kept separate from the rest of visual perception and cognition. This article should merge into those. There is already more in visual perception about the real issues here, than there is covered in this article. 142.177
- I disagree that this should be moved. I think the information currently at visual perception should be moved here. I agree that colour vision is not separate from the area of visual perception, but that doesn't mean they need to be in the same article. There is a lot more to be written about colour perception so the visual perception article would end up too large anyway. Angela 21:25, Sep 17, 2003 (UTC)
- Since I created this article, I feel I should give some explanation: I didn't want to try and fit everything into visual perception, which would have become enormous and incredibly complex, given the complexity of the subject. I thought it best to break up the various aspects of vision, even given that there is so much overlap in different aspects of vision.
- Incidentally the section on color in visual perception is, frankly, a load of crap. I'm beginning to understand why 142 was banned in the first place, pardon my brusqueness. Graft 01:14, 18 Sep 2003 (UTC)
- Pointing out specific problems with the article on the appropriate talk page would be more useful than global criticisms and personal attacks. I don't think the current stuff on colour in the visual perception article fits in particularly well with the rest of the topic and would perhaps be better on a separate page but I can't see why you're writing the whole thing off as crap. Angela 01:19, Sep 18, 2003 (UTC)
- The article (visual perception) seems to have been reconstructed as a history of the meaning of the term "colour", rather than a discussion of how perception works. Sorry for the personal attacks, I'm just rather put off by 142 tonight. Graft 01:22, 18 Sep 2003 (UTC)
- Those two things need to be separated. History of colour? Meaning of colour? Or something like that. I'd like the visual perception article to be more focused on the scientific/psychological aspects rather than the history. Angela 01:27, Sep 18, 2003 (UTC)
- I moved it all here as it is more relevant to the Color vision page than the Visual perception page. If someone thinks what is below is rescuable, they could try putting in this article. Angela 13:01, Oct 31, 2003 (UTC)
- Is there any place in this article for an alternative theory, ie Gerald Huth's (http://ghuth.com) website? --68.169.226.44 21:22, 21 Mar 2005 (UTC)
- No. That site doesn't make any sense. Graft 22:03, 21 Mar 2005 (UTC)
- Sorry that wasn't the link I meant to give, this (http://ghuth.com/A%20new%20Model.htm) is the actual paper. 68.169
Contents Colour
In these first stages, luminosity or black-white content is distinguished from red-green hue and saturation, and from blue-yellow hue and saturation. Differences in sensitivity of these causes the perception of distinct colours, such as the bands in the rainbow, which appear to have seven distinct colours to most people. Failures to tell red from green are common in men. More shades of green can be distinguished than that of any other colour.
According to John Gage of Cambridge University, figuring out what a colour word means is just as difficult as figuring out what they were thinking: the words assigned to colour represent typically associations made in cultures, and not actual frequencies.
The word "purple", for instance, referred to a dye and dye preparation technique, not the colour that resulted, in its English origins. According to Eleanor Irwin, the word referred to the shifts in colour, rather than to the colour itself - a concept we might call glamour or shimmer. Xenophenes refers to three kinds of purple, but there are in most Greek accounts only four colours (Aristotle saw just three) in the rainbow - thus he cannot mean by it what we mean. When they do refer to it as a colour, it is a much redder colour than that we would associate.
Colour words, historically, also had many other associations. The Greek chloros for instance, could mean "fresh" or "appealing" rather than "green". Other words could be either "blue" or "dark" in either the colour or foreboding sense. Not until Plato was there any clear statement that colour was a visual quality. Aristotle was concerned with iridescence but less about differing colours, and was perhaps colourblind.
By the 5th century there was some agreement on what colour was, and that it generally represented some scale between white (all colours) and black (no colours) - building perhaps on older Greek ideas about 'men as black, women as white' although these had no implications of morality. To distinguish dark from light was far more important than to distinguish any particular hue. Irwin suggests that the bright stark light of the Mediterranean influenced this view.
The painter's way of looking at colour, pigment, was also well established by this time and developed through the Renaissance.
[edit]Visual elements of cognition
Isaac Newton's work on optics was the basis of most Western notions of colour, as it was accepted as an "objective" phenomenon. But not by everyone - George Berkeley attacked Newton's work and that of Johannes Kepler as having no defensible ontology and suffering from a serious subject-object problem. Modern views tend rather more to Berkeley's than to Newton's or Kepler's in some respects - see morphogenetic field for a related issue regarding cognition in general.
Fred Brooks, in his research in the 1980s into user interfaces for complex molecular engineering problems, determined that there were no fewer than eleven distinctions in visual cognition. These included the ability to discern about two and a half degrees of freedom in colour alone, a full degree in luminosity on its own, a full degree each of albedo, one and a half of vibrato or rhythm of undulation, three spatially (height, length and width) presumably intuited by some higher cognition - he was able to use all eleven in design of user interfaces, along with two more of force feedback, and some in audio (which according to Sara Bly, Bill Gaver and Bill Buxton's work at Xerox Europarc had six degrees).
Differentiating visual from non-visual perception is sometimes quite difficult. People usually report seeing a better picture, for instance, if they hear more robust richer sound.
Newton saw a strong relation between colour and music, and was the first to divide purple into violent and indigo as a basic colour, yielding seven that matched the five whole tones (red, yellow, blue, green, violet) and two semitons (orange and indigo). Kepler had argued that musical harmony was the basis of the universe. By the 19th century music was widely considered the highest and unifying art, in effect replacing theology and philosophy and neatly managing to sidestep much ethical tradition.
[edit]Aboriginal visual perception
Studies of aboriginal languages reveal a very wide variety of names for lights and colours, which hints at highly honed ideas of the relationship between colours and survival-critical communication. Anthropological linguistics, a branch of linguistic anthropology, is concerned with this association of culture, language, and the way sensory perception is shared.
Brent Berlin and Paul Kay in their World Colour Survey claimed that all colour vocabularies were reducible to eleven terms: red and green, blue and yellow, black and white, orange, pink, brown, purple, and grey. These are the basic colour terms, and are monosyllabic, applicable to any item, highly salient, widely shared, and not included in the range of another term. But there were as few as two such distinctions made in some languages, presumably those where there was little need to make the distinctions.
Furthermore, in every single one of the six thousand languages studied, they appear in a fixed order, black and white first, then red, then either yellow or green, then the other, and then blue. Also all have the same center - that is, we all point to the same colour chit to mean the 'best example' of say red or blue.
Munsell colours are one basis of this list of centers, but brightness sometimes merges into hues, according to Robert McClury. In effect, the distinctions we make are first brightness distinctions, which is reflected in language, and then start to divide things up.
Another proposal is that the fovia, the pit in the eye where most hue receptors are located, gets opened up through a physiological response and may only become activated when there is a need to make certain distinctions.
John Gage however refutes this view, and offers historical counterexamples - including 40 of the languages studied by Berlin and Kay where there appeared to be overrides of cultural distinctions over sensory ones - such as using one word for all of yellow and orange. Homeric Greeks, Medieval Europeans, Creek Indians, and ourselves may all receive frequencies identical to each other, but describe them in different ways based upon the cultural distinctions different lifeways force on them, and this is not separable from other linguistic or sensory distinctions, just as Japanese difficulty to say or hear "L" is fixed in early life, by lack of necessity to distinguish it from "R".
[edit]Non-human visual perception
Humans have good visual perception, apparently greater than hominids in general, as great apes appear not to be able to distinguish most colours. However, it is unclear, as the view from evolutionary psychology is incomplete and poorly tested even in humans, and apes have no languages of their own which can be investigated for colour distinctions.
Many birds are drastically more visually acute, being able to spot prey at vast distances and track it as they swoop in on it.
(moved from Visual perception, originally written by User:142.177.etc)
Regarding this passage:
- Other animals enjoying three-color vision include tropical fish and birds. In the latter case multicolor perception is achieved through a single cone type. Brightly colored oil-droplets inside the cones are used to shift the perceived wavelength. Still other species have less effective two-receptor color perception systems, or simple monochromatic, single-receptor systems.
I'm slightly confused - how can birds have three-color vision with a single cone type? Is it actually "three-color" or is it a completely different non-analagous mechanism? Graft 18:25, 20 Nov 2003 (UTC)
- From what I've heard, they have both different kinds of cones and different colors of oil droplets. Of course, birds differ from each other as mammals do. -phma
See also
While the first word of the article provides a link to the article Color, I felt it desirable to mark that link in a "See also" section, because there is substantial information on color vision at that article to assist those wanting an accurate summary in the general context of theory of color. Is there any principled objection to this? It seems to me, as a relative newcomer to this whole color-and-vision domain in Wikipedia, that the domain needs considerable careful work, and disciplined re-organization. --Noetica 23:48, 5 Mar 2005 (UTC)
