Is Colour Really in Your Head?

[LostConjugate]

Resonance is not the only mechanism for frequency selectivity - you can make a bandpass filter with only Rs and Cs so no resonance is needed. You are just using the wrong terms for your ideas. What are you "grasping" from what you have read?

I am no electrical engineer but isn't that still a form of resonance that is just prevented from completing a full oscillation?

I am not disagreeing with you that the cones respond to a range of frequencies. I never did disagree with that, there are only 3 cones, they each (we will say) get excited within a "range" of frequencies.

You could also argue that if I show up at 7pm that I am actually showing up somewhere between 6:50pm and 7:10pm or 6:59:45pm and 7:00:70pm. No disagreement.

 

[Drakkith]

very wide?

I am not sure if you are grasping how small a range of frequencies a cone resonates with. It is something like .000001% of the entire electromagnetic spectrum (just guessing). Photons can carry all sorts of energy anywhere from 10^-33eV to 10^28eV I think.

I don't see how resonance has much of any meaning here. A cone cell does not oscillate back and forth nor does it store vibrational energy. Only a certain range of frequencies will make it to the cone cell and cause the chemical reaction that eventually results in a signal being sent to the brain. Attempting to explain senses and other things in terms of "resonance" is simply confusing in this circumstance. While one could argue how resonance applies to the senses and consciousness, that is beyond the scope of the current thread and belongs elsewhere in my opinion.

In regards to color perception, we need to be clear with what we mean. A cone that is labeled as Blue responds BEST to blue light. To my knowledge it has a cone shaped section covered with a pigment that absorbs less light near the blue end of the spectrum and more light as the frequencies get further away, hence giving it the response range it has. The retinal doesn't particularly care what frequency of light within this range hits it. The other 2 cells operate similarly but react better to different portions of the visual spectrum. The combination of the 3 cells and the signals they send determines the input the brain receives and interprets.

So obviously wavelength plays a great role in color perception, but it does not play the ONLY role. Physical damage to the cone cells, nerves, or brain can cause someone to have an altered perception of color. In addition, your mental state can also cause you to perceive color differently. (Among perceiving other things differently as well)

Furthermore, your brain compensates for different light intensities and even partially for entirely missing frequencies. Take out part of the blue end of the spectrum from a light source and you can usually still tell what color an object is as long as you have something to compare it too. Not as well as you could in pure white light, but enough for everday situations usually. Taken out more frequencies obviously reduces the effectiveness of this in general.

I don't see it as simple as saying color perception is based on X. A basic understanding of the whole process is needed in my opinion. Also, I see a difference between what you see normally and what you might see under the influence of drugs, injury, or something else that affects color perception. Just because your brain puts the signals together doesn't mean that it is the only thing responsible for color perception unless the discussion is ONLY about the way the brain puts together those signals and interprets them. (Which this discussion doesn't appear to be that focused to me)

 

[LostConjugate]

Only a certain range of frequencies will make it to the cone cell and cause the chemical reaction that eventually results in a signal being sent to the brain.

So this chemical reaction is not due to electron configurations resonating with the specific frequency range?

Everything else you said, I agree with.

 

[Drakkith]

When someone is color-blind, does that mean that their cones don't work right or does it means something happens to the resulting signal that makes the brain not distinguish it in the same way as the brain of someone who recognizes color?

If their cones are flawed, then I don't think my question is relevant to this discussion, but if their cones are OK, but the brain sees black and white doesn't this say something about how "color" is not frequency but a mental interpretation?

Most people who are color blind have a problem with their cone cells. Sometimes they can be missing an entire set of cone cells and only have two inputs instead of 3. Sometimes the cone cells have their response ranges shifted, resulting in much less of an ability to distinguish between certain colors, such as my dad seeing Red and Green as being almost the same color.

It is possible, to my knowledge, for something like brain or nerve damage to cause color blindness as well. The effects of that are probably much more varied than deficient cone cells.

 

[Drakkith]

So this chemical reaction is not due to electron configurations resonating with the specific frequency range?

Everything else you said, I agree with.

As far as I know, no. The pigment filters out wavelengths and only let's light within its range make it to the retinal to activate it. A stronger response simply means that the wavelength has a better chance of getting through the pigment. I'm am not an expert on this, so I could very possibly be wrong.

 

[LostConjugate]

As far as I know, no. The pigment filters out wavelengths and only let's light within its range make it to the retinal to activate it. A stronger response simply means that the wavelength has a better chance of getting through the pigment. I'm am not an expert on this, so I could very possibly be wrong.

I still think this is due to a resonance phenomenon with the electron states in the molecules of the pigment. If a system responds to a frequency of oscillation in a non-linear fashion it can always be reduced to a resonance phenomenon at the most fundamental level. However I could be wrong.

 

[Drakkith]

I still think this is due to a resonance phenomenon with the electron states in the molecules of the pigment. If a system responds to a frequency of oscillation in a non-linear fashion it can always be reduced to a resonance phenomenon at the most fundamental level. However I could be wrong.

I don't care if does or doesn't in this case, as we aren't discussing Quantum Physics. I think it just really really confuses people to try to explain things like that here.

 

[LostConjugate]

I don't care if does or doesn't in this case, as we aren't discussing Quantum Physics. I think it just really really confuses people to try to explain things like that here.

I was not meaning to go into quantum physics at all. Just thought it was clear as day that a cone in the eye resonates with certain frequencies. The term resonate is perhaps the most proper word in both its description and physical meaning. What other word would I possibly use?

However it really has nothing to do with the original conversation. Didn't expect it to generate so much controversy was all :)

 

[Drakkith]

I was not meaning to go into quantum physics at all. Just thought it was clear as day that a cone in the eye resonates with certain frequencies. The term resonate is perhaps the most proper word in both its description and physical meaning. What other word would I possibly use?

However it really has nothing to do with the original conversation. Didn't expect it to generate so much controversy was all :)

I have never seen it used that way until now. I'm not saying it is incorrect, just that it is really confusing to most people when used this way. Not a big deal in itself, but it did derail the thread for a while between you explaining it and other people refuting it.

 

[sophiecentaur]

So this chemical reaction is not due to electron configurations resonating with the specific frequency range?

This statement seems to suggest that your reasoning is based on an extension of the 'Hydrogen Atom Model'. In a condensed medium, things aren't like that. You don't have 'spot resonances' but bands of energy and a continuum of energy transitions - hence a wide band response with no explicit resonances, such as in the simple gas atom model. A resonance suggests a build up of energy in a system with a fundamental oscillatory mode. That idea doesn't apply here. The 'specific frequency range' is nearly the whole of the visible spectrum so the establishment of a colour sensation is as a result of the combination of all three sensors. Only three spot spectral wavelengths would correspond to maximum response from one of each of the three curves. Virtually all colours evoke non-zero responses from all three sensors.