Mary does and does not see Red
When Mary emerges from her black and white room to see colors for the first time to look upon a red apple, she will see the red, but she will not experience the red. The experience will come later, after she has built up associations. Furthermore, spectrum inversion is nonsense. Let’s explore these in detail.
Background of Mary Monochrome
Many of you may already be familiar with Frank Jackson’s thought experiment of Mary, who has been sequestered since birth in a room without color. Only black, white, and shades of gray. Somehow she is prevented from seeing her own skin, eyes, veins, hair, etc. She never sees or experiences color.
However, she has equipment that allows her to see the world (on grey shaded TV screens). He is an expert in the electromagnetic spectrum, in fact she is an expert in all the knowledge that there is to know about color. She knows that red is at the low end of the spectrum, violet at the high and she knows the spectrum reflected by various objects as well as the color name. She even knows neuroscience and how the various parts of the brain process visual sense. She knows everything there is to know scientifically about color, she just has never seen it.
So, when she steps out of the room, she sees a red apple for the first time directly. What does she see?
Mental Dualist Conclusion
Frank Jackson’s thought-experiment about Mary is supposed to challenge the material view of the mind. Physicalists claim that physical science can fully explain consciousness. However Jackson argues that when Mary sees the red of the apple she learns something new, despite having previously learnt all the physical facts about color vision. Thus Mary has come to know a non-physical fact; so proving that not all knowledge is physical.
Memory
Before addressing the color problem, lets start with considering how memory works. The eye is a marvelous organ, but the color red is not sensed by the eye, but far deeper in the brain. The raw sense enter, and are filtered by neural nets which extract features of what is seen. Light, dark, edges, fuzziness, curvature are detected and these are passed on to the next level which again builds on these recognizing and perceiving higher level constructs.
Each feature is represented by nerves. All of the features that are currently perceived in the environment are indicated by active nerves. That is, when all the features of an apple are present, the nerves representing those features are active. As they say: “what fires together, wires together.” The result is that the presence of one feature will cause the activation of a nerve that represents a thing with that feature.
We have all had the experience of encountering a particular smell and then being reminded of a particular situation from the past that involved that smell. You have associated that event with the smell, and so the encountering of that smell reminds you of it, because of the wiring of the nerves. It can work the other way as well: being reminded of the event might bring up the memory of the smell. You can see how this aids in perception. All human faces have slightly differing features: when all the features of a particular face are present, this cause the nerve(s) that represent the person to be activated. The result is that you recognize the person.
Memory works by associating with specific objects, which then are associated with more features and objects. Obviously, this is a highly simplified account, but the important thing to note is how memory works by association: senses are processed to features, and features trigger memory of objects and other features. A single feature will often not be enough to recall a complete memory, but a combination of features will bring a memory into mind. And it will bring to mind other details about the memory, which are other features which are associated.
Experience
What is it when you experience the color red? What happens is that the sensory input is filtered and discriminated to features, and one feature is the color red. You can think of this as a nerve that is fired whenever red is recognized. What has happened during your living experience, is that this sensation of red has been associated with many object: fire, a sunset, an apple, blood, an Italian table cloth, a fire engine, and many many other things. The sense of red itself partially activates all of the nerves that represent all things red. It will take other features of the apple, such as the roundness, the shinyness, the relative size, etc. that activate networks of nerves associated with those. But the nerve that represents the apple gets the biggest boost because so many feature of an apple has been detected, that finally the mind concludes: I am seeing an apple.
When you recognize the apple, you may be reminded of taste of an apple. An apple tastes sweet, and the mere sight of an apple — even just a picture of an apple — can bring the reminder of the sweet taste of the apple. When you look at a menu, either with or without pictures, the memory of a particular dish brings forth the memory of how that dish tastes and whether you like it or not, and whether it might the right sort of thing for your current mood. This is how you remember things (at a very simplified level): the nerves are wired together, and one getting triggered causes another to trigger.
Whenever you see red, you are seeing not only the redness of an apple, but also the redness of every other red thing you have ever seen. When you see the apple, you are also seeing blood. You are also seeing a sunset. You are also seeing a fire engine. Your experience of seeing red is all of these nerves that are associated with the feature of redness being partially activated. You feel a little bit of the fire. You recoil a little bit at the blood. You taste a little bit of the apple.
Red is considered a warm color. Why is that? Because many of the warmest things you have seen are glowing red. Never mind that of course anything glowing blue would actually a lot hotter, but we don’t see that in normal experience. When you see blue, you are reminded of dusky evening, possibly in the winter, as the light is about to go away, and the world is cold and blue. Or you might think of the blue of a lake or a stream. It is not perfectly on way or another but generally speaking blue things are cooler than red things and the color itself becomes associated with the temperature.
Qualia
The important thing to remember about this, is that the experience that you have is specific to the experiences you have had. In western cultures red is most often associated with danger. But eastern cultures associate red with joy and happiness. Because of the differences of these cultures, the people raised in those cultures have a different experience of red. Two people will experience red the same way only if their experience with red things is largely overlapping.
A considerable amount of study shows that different cultures experience color differently. Some languages have words that distinguish certain colors that speakers of other languages see as the same color. See the articles on the Himba tribe of Namibia. The associations that people have made with colors have been built over a lifetime of experience. The tricky thing to remember is that the discrimination network that processes the sensory input is also learned by experience, so as you grow up, this discrimination network get more finely tuned to distinguish the kind of colors you need to communicate with others and survive. So there is no single universal signal for “red” and there is no universe experience of “red”. The distinction of what is and isn’t red varies by your learned experience, and the qualia that you experience associated with red is also dependent on your experience.
I personally had this experience in one of my first programming jobs which was for the founder of a fashion store chain. He would sort through a stack of clothes and describe the colors with a very extensive and specific set of color names. It looked like white to me, but he said no, that was a different color: ‘winter white.’ My computer inventory system had to have color codes for all those colors which bewildered me. It should not be surprising. In the fashion industry matching exact colors that go together is particularly important, and he was quite successful at that business. His color sensors were much more highly tuned than those of a college physics student programming part time on the side. I simply did not see the differences in the color the way he did.
Stepping Out
When Mary steps out of the room and sees a red apple several things happen. I assume her retina and visual system is operating as a normal person of her culture. This means that here basic perception will deliver a “red” signal. She will sense the red. Let me describe it as a type of “tickle” because she will sense the color, but the brain will have no idea what to do with it.
The red signal is delivered to the part of the brain that does the associations, but since she has never associated anything with that signal, there will be no nerves at all triggered by that signal. She has learned the shape and other features of an apple, so she should recognize it. But red color signal is just an extra feature. The apple will look different, but she will not be able to put her finger on exactly why it looks different. She has not trained her brain to recognize the red signal from the optical system. She will sense the red, but she will not experience the qualia that we normally associate with red things. When she sees the red for the very first time, there is nothing that her mind can say it looks like.
As she says in the colored world, she will learn quickly. As she sees more and things that always appear with a red sensation will be associated with the red feature. As she continues to live in the colored world, red will slowly take on a meaning of its own. This is quick simply because all of the things she has associated with red are now becoming partially triggered when red appears.
I mention above assuming that her visual system is working, because the brain is so adaptive (neuroplacticity) the brain seems to allocate space to processing that is needed, and discards parts that are not. Thus living an entire childhood without color might allow the color recognition parts of the brain to atrophy or to be reallocated to other uses. Also an expert in neurology is presumably an adult, and adults do not learn as quickly or effectively as children. But let’s play along with the thought experiment and assume that Mary is not permanently color blind due to the experience.
Philosopher’s Point
The point of the thought experiment is to demonstrate that Mary learns something about red that is not based in the physics of the universe. This leads to the conclusion that qualia that is something beyond the physical.
I disagree.
Mary has never directly sensed red before. This is clear, and not surprising. No amount of reading about the color red, and no amount of examination of spectra on (black and white) graphs is going to activate your visual perceptive system. Nobody should be surprised or find it in any way controversial that she is sensing red for the first time. She is using a sense she never used before that could never possibly be used in the black and white room.
It seems however that the non-physical dualists believe that the subjective experience — the qualia — that is associated with red will just spring magically into existence. This is just an assumption. Instead I believe that we are not born with the subjective experience we associate with red.
We have to learn to experience red in the same way we learn to speak a language or to play an instrument.
Mary can not learn to associate objects with the red color signal until she leaves the room, but what she learns is not extra-physical. It is quite simply that the only way to present a red feature signal to the learning part of the brain, is to look at a red object. Without the signal, the brain does not make an association. She has absolutely no association with red, and so when she steps out of the room, she sees no color. That is: she senses the colors, but she has no qualitative subjective experience associated with the sense of color. She will see a gray apple that has a strange new sensation about it which she can not (yet) place.
There is a second possible interpretation of the story. It take place in the far future where everything about the brain is known. If Mary has a catalog of all the red things, and the technical ability to generate a red signal in the brain, then it would be possible that she trains the brain to experience color. Then of course when she steps out of the room she sees the colors exactly as trained. However this interpretation seems to defeat the purpose of the scenario and seems unrealistically far fetched even for a thought experiment.
All of this is accomplished with a material brain. There is nothing extra that she learns, except that she must train her brain to handle signals she has never received before. There is no additional information, it is only that to learn to see a color, you have to actually see the color. Knowing the wavelength of red light will never give her the situation necessary to learn to associate objects with the color. There is nothing here that rules out a material mind.
Bicycles
One might propose the same experience with regard to riding a bicycle. Mary might be an expert on every aspect of a bicycle, both mechanically as well as the theory about how to balance. But reading about a bicycle will never give her the skill necessary to ride one. She can pick up this skill by actually getting on and trying. Even though you know everything about it, you can’t actually train the brain without actually doing it.
We can not conclude that bicycle riding involves something non-material. The physics of bicycle riding is completely understood, but she will never know how to ride one by reading a book. Picking up this skill is nothing magical, but simply a matter of training her reflexes.
Inverted Spectrum
This is the old question: what if you see red, the way I see green? Even though you see it like I see green, you would still call it red. We could point to thing and agree on the red things. There would be no way to know that you and I were perceiving it differently.
This is another nonsense proposal based on a misunderstanding of how the perception of color works. The person who seriously considers this a possibility is making an assumption, and that is that the quale of color is something that pops into existence from somewhere else.
On my explanation that you learn to perceive colors, two people who grew up in the same environment and had similar experiences will always perceive the color the same way, because that perception is simply the amalgam of associations with everything that is that color. There is no possibility that my red might be switched to be like your green.
Conclusion
The Mary Monochrome thought experiment is designed to show that a material (physical) description of the brain can not account for all our subjective experience of things (qualia). It fails to do this because it starts with the assumption that there is something more to the brain than the physical. Then it sets up a situation consistent with this assumption, and ends by concluding the assumption.
What I have tried to do here is give a material view of the working mind which does not assume that the means for subjective experience appears magically from somewhere else. Those experiences are learned experience. The brain does this learning in order to give you the subjective experience.
There is nothing new for Mary to learn about color when she exits the room. She already knew all there is to know. But the brain had not been trained to associate all the red things. The brain had not been wired. This is not the slightest bit surprising. Furthermore, after she has lived in the colored world, she can begin to make those connections. She learns, but this learning is simply making connections based on well understood phenomena, not a magic facility that comes from elsewhere. She learns nothing new at all. Everything that drives the rewiring of her brain was already know.
In conclusion, Mary will sense the redness of the apple, but will not have any subjective experience of redness until she has wired her brain to make real world associations with red objects.
Questions and Answers
Does Mary learn a new Skill? – Yes, I like this description very much. Mary may know everything about color, but she has never actually done it herself. She might also have learned everything about riding a bicycle, but still does not have the skill of riding a bicycle. She does not have the muscle memory. A skill is something you consciously train your body to do, by doing it, critiquing the results, and improving. To experience color, she needs to learn the skill of seeing the color, which is something that we all do at an age too young to remember.
Why do we assume we know what she will see? – The original posed thought experiment is based on the assumption that when she looks at the red apple, that she will see it red. Why is it that we expect this? How would we know this? We don’t. The thought experiment is not very useful because we don’t really know what she would experience in that situation.