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it's still fundamentally unanswerable though, which means it's effectively both true and not true, because it cannot matter.
The age old question that pops up in the joint circle
This is completely missing the point, which is that qualia are only experienced by the conscious mind. They cannot be measured by anything other than the mind of the person experiencing them.
Measuring that the brain activity is the same is not sufficient to prove this unanswerable philosophical question. You would have to also prove that different minds have the same experience while exhibiting the same neural activity - a problem which reduces to the same question: is my experience of blue the same as yours?
You would have to also prove that different minds have the same experience while exhibiting the same neural activity
i don't agree with this reasoning. why would the same neural activity result in a different experience? other than reactionary doubt and preconcieved belief, what reason do you have to actually question this? you seem to be smuggling in an assumption that the same neural activity could result in different experiences, isn't this a positive claim that requires its own proof; wouldn't the null hypothesis be that similiar phenomenom play out similarly until there is shown a reason to believe otherwise?
As an analogy, just like dragging a 1000kg at 1m/s is not the same experience as dragging a 10g sphere at 1m/s. The same thing happened "something moved at 1 m/s", yet they were very distinct experiences.
That being said, Occam's razor applies here. If it's the same brain activity, it probably results in the same experience.
But there's still room for doubt. Since brains don't all have the exact same amount of neurons arranged in the exact same way. And their chemical composition might be slightly different. They also change with age.
I don't think science can prove definitely that a slightly different brain structure won't result in a different perception of color. Just like it can't prove/disprove the existence of god. Some questions are just unsolvable. But science can get far enough so we say "this is probably true/false"
Two people can have a different experience of smell and taste despite the input as well as the way their brains are processing that input being the same. While not a perfect analogy, I don't see why assuming that everyone experiences colors the same would be any different than assuming that everyone likes the same food.
I'm not saying I definitely believe that everyone does share color experience, I'm saying the evidence presented in OP seems to suggest they could share color experience, and that evidence should not be simply dismissed. It's not direct evidence for the belief imo, it's more like evidence that suggests new lines of inquiry.
Because the brain's neurons aren't identical from person to person.
Just because basic research doesn't resolve a question perfectly does not imply that it 'missed' the point. I think this is a serious mistake in a lot of people's understanding of science, and it's worth sitting on.
Most things we learn are incremental.
This is normal. An experiment is not bad just because it is incremental. We should be looking at every opportunity to chip away at seemingly impossible questions.
And I think the study here is unusually high in information gained and context relevance. This experiment could have given extremely strong evidence that we do see colors differently than each other, because if we have different neurological reactions it would be pretty weird for our qualia to agree (most physicalist descriptions would have consider it proved that we see different colors). If, when we both see blue, our brains light up in very different ways, that would be weird!
So this is a point in favor of shared qualia. It doesn't resolve the question; that will require several new ideas, breakthroughs in consciousness, and a lot of back-and-forth with philosophy. But it damages any theory that qualia are different because of brains being different, and that's cool.
It is possible that you've defined qualia as explicitly non-physical (and so must posit a bunch of extra stuff for this study to stay irrelevant). This is done in some circles, but is not standard afaict. It comes in as definition (4) here, after several that are consistent with the study and OP's use.
I have noticed that you can broadly put people into two cups.
People who understand why this is an unanswerable question, and people who say "Bro, what the fuck are you on about, I can see blue just fine, it looks the same as it does for anyone."
Both of those cups are out in force in this post.
I think this is the closest we have ever gotten to being able to answer the question. But yes, it might not ever be completely solvable
I keep seeing these types of articles periodically and the reductionism is always assumed to be valid. It bothers me so much.
Yeah:
It’s a question that has puzzled both philosophers and neuroscientists for decades, but has proved notoriously difficult to answer
No, dumbass. It was always obvious it's unknowable.
The amount of pretentious BS pseudoscience replies in this thread is too damn high. This is quite an amazing study.
Yeah people saying it's BS because it has a catchy title is pure anti science doomerism
Participants 120 We analyzed fMRI data from N = 15 (2 male, 13 female) participants aged between 22 and 35 121 years (mean: 25.5) who took part in a previously published fMRI study about color vision 122 (Bannert & Bartels, 2018). The participants were the subset from the prior study for whom the 123 cortical retinotopic representations of the visual field were measured along both the polar and 124 the eccentricity axis of the visual field. All participants had normal or corrected-to-normal visual 125 acuity and were tested for normal color vision using Ishihara color plates (Ishihara, 2011). Each 126 participant gave written informed consent before the first study session. The experiment was 127 approved by the local ethics committee of the Tübingen University Hospital.
Ignore the numbers 120-127, those are line numbers.
Doesn't say. To be fair, you normally aren't allowed to collect biographical data or any additional identifying data without a specific purpose tied directly to your research question. If they wanted to answer your question they would have to redo the study under a different IRB application. Interesting question, but I would guess you wouldn't see a difference in an fmri. The voxel sizes for functional are normally 2mm while what you are eluding to is the difference of a few thousand neurons wired a little differently. That difference would be extremely difficult to detect with 2mm voxels. Even at 1mm it would be difficult. When it comes to brain structures there really aren't significant different between races or cultures more than the variance that already exists between people.
That checks out, thanks for pointing this out. I'm much more familiar with clinical trials where ppl's race/ethnicity do play an importance (and is also a hot topic for debate... from both sides of the political spectrum), hence I was a bit surprised they didn't include it. If there really is no significant cultural differences that would be amazing
Also one can dream they get 120+ participants for scanning
N=15 is a normal size on FMRI studies. It is about the smallest size you can have and still make your significance cut offs while still detecting decently small effects. The time and cost is so much higher than other studies. Some of the bigger FMRI studies start to reach 30-40 ppl. Getting into clinical trial sizes of subjects is unheard of.
The other thing with FMRI studies that most everyone doesn't understand is that they aren't actually looking at activity. They are looking at the BOLD response (blood oxygen level dependance) and that is then correlated to activity. Meaning You can only see blood oxygen uptake. You are not seeing neuron firing, just the metabolic side effect of oxygen use after increased neuron use. This is why you will never be able to see something like a "thought process". You can only track structures/locations used.
At the same time we know that no two brains are wired the same even for the smallest of tasks, but they will "structure" their wiring the same. There have been literally hundreds of studies that indirectly see that. Soeach other. Plot out cultural differences versus individual differences would be basically two variance plots on top of eachother.
Well, I have two eyes. Yep, it's true. And they both see a different shade of blue.
So, my take is that if my eyes are unable to agree on the same shade, or colour, then it may be amazingly different between people as well.
...fifteen participants? pfft
To give them credit... neuroscience and scanning ppl's brain is expensive lol. But yeah, 15 participants and no open access, I have no clue exactly what or how they did this
The blueness of blue is entirely a subjective experience and no matter how detailed measurements you're able to take from the brain you still can't conclude that person A has the same experience of blue than person B. Colors are not real. It's just how your brain intreprets a wavelenght of light.
Every colour you “see” is an interpretation of incoming light data to the eyes transformed into nerve signals to the brain. Each person has a different set of eyes and nerves, so it is likely that each person interprets (“sees”) colour differently.
TLDR: colours are a pigment of the imagination
pun is great, but the point of the article is that the first bit seems to be wrong. You can use brain firing patterns in one person to predict which color another person is seeing afaict. In other words, we're using the same nerve circuitry in extremely similar ways.
It gets much more complicated when we understand that there is no such thing as color. Color is created by the brain.
The only thing that really exists are photons with different energy levels, there's no such thing as color really.
What the human is absorbing is the energy level of the photons, and it's being perceived as color.
I've always wondered about this. Good to have some evidence.
It's not really evidence, the question if we perceive the world the same way is deeper and more fundamental to experiencing the world. It's not a mechanical question that can be answered materially.
So happy to see something in this direction! Commentary is also excellent, looking forward to reading a review of many instances of this study.
Fun site related to the discussion
Granted, there's also issues of screen quality/accuracy
I have extensive personal experience indicating that I do not align with this claim.
"Pink"/"purple" and "blue"/"green" just do not work for me the way they do for anybody else it seems, it's been nearly five decades and, despite effort, I am barely better than chance when one of my kids something up and says "what color?"
Have you taken a colorblindness test?
Yes.
Not rated as color blind, but some of them were pretty fucking subtle.
You might look into getting checked for cone-rod dystrophy. Seeing colors differently than my wife, but still passing a color blindness test is what led to the extra testing that led to my diagnosis.
Huh cool. Were you able to make changes to align better with others after the diagnosis, or is it just a relief to know?
There's no change or cure. My color vision is going to slowly disappear, then I'll slowly go blind. The timeline on that is anywhere from like a few months to 50 years, depending on which gene is causing it (I haven't done that test yet). The fact that there hasn't been a major change yet is a good sign though.
Good news is there's a bunch of trials for drugs that can slow or stop it going on right now, and my opthalmologist happens to have a lot of experience with it.
Best of luck! I'll keep my fingers crossed, I've been like this my whole life and I'm not noticing any degeneration. I'll also bring it up at my next doctor's appointment and see what he thinks.
Blues are all the same, but what you see as red is how octarine looks to me. Red's a real grab bag, blue is the weird one.
I mean they probably wanted to eliminate some variables before expanding the experiment
this post was submitted on 09 Sep 2025
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