DavidMcC wrote:Before intermarraige with the Herero tribe, they were likely all tritanopes, (insensitive to blue light, because the refractive index of the human lens starts to change in the blue, and this would slightly blur their distance vision - an important issue for a tribe that has to spot tiny dots on the (blue) horizon. I wrote a thread on this a few years ago. It's mainly biology, not learning, that affects their vision.

After reading the actual paper it seams tritanopia was ruled out by testing children before language bias had set in. So this would falsify your hypothesis.

Roberson et al. (2004) addressed these questions in a study that included a
group of young English children, who were tested initially before they entered
pre-school and, subsequently, through three years of formal education, and a
group of Himba children from northern Namibia, few of whom received any
formal education during the period of the study. Himba has five BCTs
according to the criteria of Kay et al. (1991). Children’s colour term knowledge
and memory for colours were tested at six-month intervals over three years. At
the first test, 32 English three-year-olds and 36 four-year-olds were tested,
along with 42 Himba three-year-olds and 27 Himba four-year-olds. In the
longitudinal sample, 28 of the English three-year-olds and 63 of the Himba
children completed all six tests. All had normal colour vision.

https://www.researchgate.net/publicatio ... nd_English

laklak wrote:Mrs. Lak can see all sorts of imaginary colors. I see beige, she sees cream, Tuscan, buff, Desert Sand, ecru, khaki, taupe, camel, and probably a few others.

Beige. It's all beige.

This reminds my of the GREEN trousers I had which turned out to be BROWN.

CdesignProponentsist wrote:

DavidMcC wrote:Before intermarraige with the Herero tribe, they were likely all tritanopes, (insensitive to blue light, because the refractive index of the human lens starts to change in the blue, and this would slightly blur their distance vision - an important issue for a tribe that has to spot tiny dots on the (blue) horizon. I wrote a thread on this a few years ago. It's mainly biology, not learning, that affects their vision.

After reading the actual paper it seams tritanopia was ruled out by testing children before language bias had set in. So this would falsify your hypothesis.

...

There is no correspondence between Himba words for colour and English words for colour, so that a Himba might use the same word when an English person would use different ones for different actual colours. (Eg, yellow is described by the same Himba word as is used for white.) The likely reasonfor this is that the ancient Himba were likely tritanopes and modern Himba have lost the tritanopia, but retain the liguistic characteristics of it. (Eg, the sun is described as being the Himba version of "white")
Also, you have not answered the point that, if this was a real vision effect of language, why does it only affect the Himba? This does not make sense, except as a linguistic ambiguity in Himba words for colours, due to the shortage of those words.
Another example of Himba colour words is that they are taught that black is the colour of the daytime sky, but this is again cultural linguistic baggage, because, as you rightly say, they are no longer tritanopes, because of centuries of interbreeding with trichromats.

... I apologise for forgetting to include the above point earlier in this thread.

As for romansh's point about yellow being an illusion when it is due to the combination of red and green, without any monochromatic yellow. Thus, the crux of this is what is meant by the word, "illusion". What the two forms of yellow have in common is that both excite the red and green cone cell types equally (when integrated over sufficient time and/or space), while not exciting the blue cones significantly. Why call one an illusion, yet not the other, when they essentially have the same cause, differing only in the detail?

Romanish

The photons themselves are not red!

I think you have a fundamental misunderstanding of photons and wavelengths. See Cali's references,

........

Someone earlier said it "happens in the eye not the brain"....

Unnecessary complication ...the eye is part of the neural net ....stick with that.

,,,,,,,,

This is pretty good walk through

http://www.workwithcolor.com/colors-of- ... w-6987.htm

including colour vision

http://www.workwithcolor.com/color-vision-1089.htm

There certainly ARE colour illusions that involve yellow. When I worked in a yellow room (in which the lightlng has blue light filtered out to avoid exposing photoresists prematurely) I noticed that not only did surfaces that look white in "normal lighting" look yellow when the yelow room lighting is on, but also, yellow surfaces looked white! I guess it was the overall colour balance in the room being distorted.

Macdoc wrote:Romanish

The photons themselves are not red!

I think you have a fundamental misunderstanding of photons and wavelengths. See Cali's references,

Is the statement wrong?
Or do you think the photons at ~600 nm are red ... I certainly don't.

DavidMcC wrote:There certainly ARE colour illusions that involve yellow. When I worked in a yellow room (in which the lightlng has blue light filtered out to avoid exposing photoresists prematurely) I noticed that not only did surfaces that look white in "normal lighting" look yellow when the yelow room lighting is on, but also, yellow surfaces looked white! I guess it was the overall colour balance in the room being distorted.

Yep ... a yellow bullrail in the snow at night under sodium vapour illumination.

romansh wrote:

DavidMcC wrote:There certainly ARE colour illusions that involve yellow. When I worked in a yellow room (in which the lightlng has blue light filtered out to avoid exposing photoresists prematurely) I noticed that not only did surfaces that look white in "normal lighting" look yellow when the yelow room lighting is on, but also, yellow surfaces looked white! I guess it was the overall colour balance in the room being distorted.

Yep ... a yellow bullrail in the snow at night under sodium vapour illumination.

Sure, but none of this makes colour perception inherently illusory, just more complicated than we might at first think.

EDIT: If vertebrates had evolved with sodium lamps around, we might have evolved a slightly different colour vision system - one that sees through this effect. As it is, the visual system is fooled, but not also the mind.

DavidMcC wrote:

romansh wrote:

DavidMcC wrote:There certainly ARE colour illusions that involve yellow. When I worked in a yellow room (in which the lightlng has blue light filtered out to avoid exposing photoresists prematurely) I noticed that not only did surfaces that look white in "normal lighting" look yellow when the yelow room lighting is on, but also, yellow surfaces looked white! I guess it was the overall colour balance in the room being distorted.

Yep ... a yellow bullrail in the snow at night under sodium vapour illumination.

Sure, but none of this makes colour perception inherently illusory, just more complicated than we might at first think.

EDIT: If vertebrates had evolved with sodium lamps around, we might have evolved a slightly different colour vision system - one that sees through this effect. As it is, the visual system is fooled, but not also the mind.

While I don't disagree with this or any of general descriptions of the science behind colour.

But ultimately, the redness that I experience, is a product of my brain. The bus itself is not actually red.

romansh wrote:

DavidMcC wrote:

romansh wrote:

DavidMcC wrote:There certainly ARE colour illusions that involve yellow. When I worked in a yellow room (in which the lightlng has blue light filtered out to avoid exposing photoresists prematurely) I noticed that not only did surfaces that look white in "normal lighting" look yellow when the yelow room lighting is on, but also, yellow surfaces looked white! I guess it was the overall colour balance in the room being distorted.

Yep ... a yellow bullrail in the snow at night under sodium vapour illumination.

Sure, but none of this makes colour perception inherently illusory, just more complicated than we might at first think.

EDIT: If vertebrates had evolved with sodium lamps around, we might have evolved a slightly different colour vision system - one that sees through this effect. As it is, the visual system is fooled, but not also the mind.

While I don't disagree with this or any of general descriptions of the science behind colour.

But ultimately, the redness that I experience, is a product of my brain. The bus itself is not actually red.

You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

DavidMcC wrote:
You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

So you actually believe the (London double decker) bus is physically red ... ie the same colour as you experience in your mind's eye?

DavidMcC wrote:
You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

Science makes a mockery of your naive realism.
Colour is a quale of experience. What you are experiencing subjectively, is differences in the wavelength of light in objective terms.
This is obvious enough since we can demonstrate that humans have at least three different modes of colour perception due to genetic differences; and the colour perceptions of animals varies also from human colour perceptions.

romansh wrote:

DavidMcC wrote:
You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

So you actually believe the (London double decker) bus is physically red ... ie the same colour as you experience in your mind's eye?

I don't need my mind's eye to see the colour red, as I have normal, trichromatic vision with my actual eyes. I'm guessing that you don't, perhaps due to (protanopia), so that you have to imagine red, right? That's the only explanation I can think of for your strange posts.

Hobbes Choice wrote:

DavidMcC wrote:
You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

Science makes a mockery of your naive realism.
Colour is a quale of experience. What you are experiencing subjectively, is differences in the wavelength of light in objective terms.

Yes, sure, which is exactly why the experience of red when you see a London bus is down to the paint on it and not just people's imaginations.

This is obvious enough since we can demonstrate that humans have at least three different modes of colour perception due to genetic differences; and the colour perceptions of animals varies also from human colour perceptions.

That is misleading, because the genetic variants on the LW and MW opsins differ in peak wavelength by only about 5nm, so the red is still red and the green still green. And of course different species have different kinds of cone receptors (if any) with different kinds of cone opsins, so they see colour differently from us (if at all).That is well known, and has nothing to do with this discussion.
Perhaps you though my reference to physical colour meant that I thought that we directly sense colour, or something daft like that. Or, more likely, you are trying to paint me in stupid colours.
I thought it was well known that "physical colour" refers to the spectral reflectance of a surface. If you didn't know that, what are you doing here - trolling?

PS, like most scientists, I'm an indirect realist, not a naive direct realist.

DavidMcC wrote:

Hobbes Choice wrote:

DavidMcC wrote:
You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

Science makes a mockery of your naive realism.
Colour is a quale of experience. What you are experiencing subjectively, is differences in the wavelength of light in objective terms.

Yes, sure, which is exactly why the experience of red when you see a London bus is down to the paint on it and not just people's imaginations.

This is obvious enough since we can demonstrate that humans have at least three different modes of colour perception due to genetic differences; and the colour perceptions of animals varies also from human colour perceptions.

That is misleading, because the genetic variants on the LW and MW opsin genes differ in peak wavelength by only about 5nm, so the red is still red and the green still green. And of course different species have different kinds of cone receptors (if any) with different kinds of cone opsins, so they see colour differently from us (if at all).That is well known, and has nothing to do with this discussion.
Perhaps you though my reference to physical colour meant that I thought that we directly sense colour, or something daft like that. Or, more likely, you are trying to paint me in stupid colours.

PS, like most scientists, I'm an indirect realist, not a naive direct realist.

A bus painted "red" appears so because the light it reflects has a different wavelength. When we perceive redness that is something wholly different. We can never even tell if one person's experience of red is anything like another's, we can only assume that. In fact given what is laughingly called "colour blindness" we can be sure that our experiences are different.
The internationally celebrated dress that appears to some gold and blue, and to others black and blue, should be enough for you to understand that not only can we not be sure out experience is the same as others but that the human brain is in a constant state of interpretation and reinterpretation of the colour balance.
The brain filters out the colour shifts from warm artificial light to the cold blue day light, as any photographer can tell you; and the consequence of this is that we miss the true nature of the redness of the sunset, by subjectively and unintentionally changing our internal hue setting.
No one is saying that paint does not exist, and that it has different light reflecting properties; but that the quality of each colour is about cerebral experience and not an objective quality of reality.

The Mononchrome Mary thought experiment of this issue is very instructive.

Hobbes Choice wrote:

DavidMcC wrote:

Hobbes Choice wrote:

DavidMcC wrote:
You only experience red when you see a bus when the physical colour of the bus is red, barring non-neutral lighting conditions, of course (eg, a silver bus with a red light shining on it).

Science makes a mockery of your naive realism.
Colour is a quale of experience. What you are experiencing subjectively, is differences in the wavelength of light in objective terms.

Yes, sure, which is exactly why the experience of red when you see a London bus is down to the paint on it and not just people's imaginations.

This is obvious enough since we can demonstrate that humans have at least three different modes of colour perception due to genetic differences; and the colour perceptions of animals varies also from human colour perceptions.

That is misleading, because the genetic variants on the LW and MW opsin genes differ in peak wavelength by only about 5nm, so the red is still red and the green still green. And of course different species have different kinds of cone receptors (if any) with different kinds of cone opsins, so they see colour differently from us (if at all).That is well known, and has nothing to do with this discussion.
Perhaps you though my reference to physical colour meant that I thought that we directly sense colour, or something daft like that. Or, more likely, you are trying to paint me in stupid colours.

PS, like most scientists, I'm an indirect realist, not a naive direct realist.

A bus painted "red" appears so because the light it reflects has a different wavelength.

Different from what? Physical red is 600-800nm wavelength.

When we perceive redness that is something wholly different. We can never even tell if one person's experience of red is anything like another's, we can only assume that. In fact given what is laughingly called "colour blindness" we can be sure that our experiences are different.

What's laughable about having fewer cone cell types than normal, or a damaged optic nerve, or other problem?

The internationally celebrated dress that appears to some gold and blue, and to others black and blue, should be enough for you to understand that not only can we not be sure out experience is the same as others but that the human brain is in a constant state of interpretation and reinterpretation of the colour balance.

Ha! As someone pointed out at the time, that was just a heavily over-exposed photograph by an incompetent press photographer, making the blue look white and the black gold.

The brain filters out the colour shifts from warm artificial light to the cold blue day light, as any photographer can tell you; and the consequence of this is that we miss the true nature of the redness of the sunset, by subjectively and unintentionally changing our internal hue setting.

I know that, it's called colour optical illusions, but it isn't anyhting like sufficient to make a black & blue dress seem gold & white!

No one is saying that paint does not exist, and that it has different light reflecting properties; but that the quality of each colour is about cerebral experience and not an objective quality of reality.

The Mononchrome Mary thought experiment of this issue is very instructive.

The problem with Mary's room is that it is unscientific, becase no mother would allow her baby to be brought up in a totally b/w environment for years. Therefore, you can impose whatever "result" you want on it, and no-one can contradict it with evidence to the contrary.

DavidMcC wrote:. evidence to the contrary.

..
Seriously, I don't think you've thought all this through. You get to a point is a discussion when you realise that your interlocutor is not receiving. I think we are done here.

Hobbes Choice wrote:

DavidMcC wrote:. evidence to the contrary.

..
Seriously, I don't think you've thought all this through. You get to a point is a discussion when you realise that your interlocutor is not receiving. I think we are done here.

Interlocutor?? WTF?
Maybe it's you that needs to think colour vision through more carefully!