How to create a robot that has subjective experiences, part 3

What makes colour phenomena “atomic”?

From Narrow To General AI
13 min readJul 6, 2024

This is part three of a series on the mechanics of conscious experiences. I recommend starting with part one and part two, as this post builds on those foundations.

In the previous post we discussed how pain, being both a motive and a sensory stimulus, drives your understanding of its phenomenal experience by filling your mind with whatever thoughts and judgments help you avoid it. You could just as easily apply this pattern to positive experiences such as the pleasure of opiates, which search for and associate thoughts about them being “pleasant”. On the other hand, the experiences of neutral — non-motivated — stimuli, like those of colour or shapes (contrast) cannot reasonably influence your thoughts through motives. The driving forces that create your understanding of them must come from outside the stimuli themselves. How this could happen still needs to be explained.

A further difference between pain and colour is that the phenomenal experiences of colour seem more immediate, more concrete, more clear in your mind than those of pain, which feel fluid, abstract, and mercurial. You can firmly “grasp” colours in thought, whereas you can’t do the same for pain or pleasure. We’ll delve into these and other riddles in this post, all within the framework of motivated cognition so far described.

Let’s start the investigation into colour phenomena by using a well-known thought-experiment, titled Mary’s Room. In our version, we’ll imagine that a woman named Mary, having been raised for several years in a room that did not contain the colour red, were suddenly exposed to a red object. On seeing this new colour, it would be fair to assume — and many philosophers have argued — that Mary would learn something new about the world. And in a sense that is true; nothing anyone told her before could ever encapsulate a comparable change in her mind:

It follows that the facts about the subjective experience of color vision are not entailed by the physical facts. If they were, Mary could in principle come to know what it is like to see red on the basis of her knowledge of the physical facts. But she cannot. — Chalmers, The Conscious Mind

This is not to say that Mary is exposed to a real entity, i.e. the qualia of the colour red, as Chalmers proposes in his book. To learn a fact of any kind involves a specific, concrete physiological change in one’s brain, and until now Mary had simple never had the opportunity to alter her brain in that respect — via the channels associated with the colour red — nor drive her judgments through those pathways.

Mary, raised in a room without red, sees red for the first time and learns something she could not know beforehand.

For example, as the red inputs to her mind are activated for the first time, she finds she can now form memories of these experiences, and recreate them later by recalling them as thoughts. She may compare those memories with other sources of colour input and form judgments about their similarities and differences. She can even associate red inputs with feelings, concepts, moods, etc.

With time, her experiences of these new phenomena will become multi-faceted, with each aspect being shaped by the approach (i.e. motive) from which she arrives at it in a given moment. For example, Mary may try to discover an appropriate way to express her feelings about a red object to others; assuming she has been socialized to want to engage in conversation. She may take delight in experiencing the colour over and over in her mind as a kind of pleasant novelty, to while away the boring hours. Or she may feel uncomfortable with the alien nature of the colour, which causes her mind to reject any thought of it, replacing it with thoughts of more familiar colours.

Cutting across these individual interactions will be two general categories of her interpretation of the experiences; in some cases she will interpret the experiences as expressions or English words (colour → word), and in others we will try to recall an experience of red based on a cue (word → colour). These are two separate types of recollections, learned at different times and for different reasons. All in all, the diversity of Mary’s psychological changes when she sees this new colour cannot be encapsulated in a single event called “learning red”.

In the previous post we suggested that all thoughts that are connected to (and thus interpretations of) your experiences must be learned by an act of searching for and “becoming aware” of the thought in question. Phenomenal-type thoughts — e.g. what red “feels like” — are included in this set of interpretations; and as such they must each have a driving motive that triggers you to search for and become aware of its interpretations. She would have to ask herself questions like “what does red feel like?” or “does red have a distinct qualia-property?” or “how is red different from blue or pink?” Her understanding of red will be the sum total of the thoughts she has in response to these questions. So the problem for us becomes: what would cause Mary to want to attach phenomenal-type interpretations to her experience of these new colours?

At one extreme, it is entirely possible that the first time she sees red, she doesn’t even notice the new colour, because she has no reason to — no more than a child who has never heard a C# arpeggio may be surprised when he first hears one¹. She may simply integrate it into the rest of her sensory inputs, perhaps referring to it as an “off-brown” colour; in the same way that ancient Greeks referred to the sky as bronze and the sea as wine-purple — they simply had no reason to have any clear designations for blue or dark blue.

But say that she were going around her room, trying to see if she could clearly distinguish all the colours she sees. Her mind, through socialization, has learned to generate a request whose function is to situate the colour within a recognized palate². She may now realize that the red object does not fit any of the categories for which she has learned socially-sanctioned labels. Her inability to match red to any colours in her memory means the underlying tension — i.e. “what name should I match this experience to?” — remains unresolved. This is similar to the tension that pushes you to discover the proper name to attach to a new acquaintance’s face. Once found, the mind attaches the interpretive thought — i.e. knowledge — to the original stimulus.

This is not a phenomenal judgment, only basic identification by naming; something that can be done unconsciously or habitually. The experience of phenomena, on the other hand, is the result of trying to break down and attach an analytic identity to an experience, to find its properties, or its nature. As an analogy, you may decompose your mental image of a car into its wheels and body, or the property of shininess. The roots of this motive are a sort of compositional or constructive interest — “how could I create this if I wanted to?”

Colour can’t be analyzed

Say that Mary tries to analyze what this new experience of the colour red “is”, and why it is so. The question “what is it?” must always find a thought as its answer. The mind is looking for a visual or auditory thought that will count as the “correct” analytic interpretation. But what thought can she connect the colour red to that counts as a valid answer? As she looks back at the colour, in her memories or in reality, what does she see are its components?

Colour experience has no parts. It is a primitive, in that it cannot be decomposed. The only answer her mind can arrive at is to just register a thought of the colour itself. “What is that red thing? It is red”. Colour, unlike pain or tactile sensations, can be recreated in the mind. And so it can refer to itself in thought, because the thought you attach to represent it can itself be an image of a colour. You cannot think of pain, only of images and sounds you’ve associated with pain. So unlike pain, which feels abstract, colours feel concrete and tangible because you can always bring them back to themselves in thought. In short, seeing the colour red can make you think of the colour red.

Your explanatory thought regarding a colour often leads right back to the colour itself.

This self-reference makes the colour appear “atomic”, because it appears it cannot be broken down. Its analysis (literally “to separate into threads”) always arrives back at itself. “What is red? It is red.” No other thought is particularly appropriate. As you focus on the phenomenon, your mind alternately stores and recreates the colour in thought. So the same thought returns every time you ask, causing it to signal the same pathways, which makes it appear static, like the colour has a persistent existence of its own.

Trying to define conscious experience in terms of more primitive notions is fruitless. — Chalmers

Anytime you feel confident that you know the quale of red, that it exists as a unique piece of information, you are recreating the colour in your mind, re-experiencing it as a thought in a never-ending circle. This is the sum and extent of what you can know or believe about a colour.

The unseen machinery of judgment

Since a given colour quale cannot be broken down, it is impossible to identify it via any proper features of its own. Unlike a car, which could be defined through thoughts of wheels, a body, and an engine, colours cannot have subjective definitions. A colour only gains its particular, unique definition when contrasted to other colours.

To clarify this somewhat counter-intuitive point, imagine someone who was born colourblind (monochromacy). They would not see any distinct colour qualia at all, only a sort of monochromatic tint. It is difficult, however, to say if this single shade of quale would be identical to the quale of blue, or of green, or of grey, or if the question itself doesn’t make sense. As discussed in a previous post, qualia do not have any stable identity outside their momentary comparisons. It is fruitless to try to compare the qualia of a monochromatic individual with the qualia of blue at some other time, or in another person. Colours must be immediately contrasted with other colours in the same mind. This act of judgment plays a large role in what it means to define a colour, since there is not much else you can do.

So how would Mary, on experiencing red for the first time, come to experience the difference between the new colour and any existing ones? How does she realize that the colour she is experiencing does not match any of her memories of other colours she may bring to mind? The answer is surprisingly straightforward: the underlying unconscious mechanism of colour matching doesn’t give her the option to think about the new colour any other way.

To know that two colours match, the subconscious machinery must inform your conscious judgments of the match. Again, the difference between conscious and subconscious is illustrative only; it is not a real distinction.

Matching or distinguishing colours already happens mechanically “under the hood” of your consciousness. Your eyes and visual cortex process colours as similar or different long before you start to ponder their subjective qualia, and it is possible to make unconscious colour distinctions without becoming aware of them as phenomenal experiences. This is why, for example, you do not have to be consciously aware of the red in a stop sign to obey traffic rules while driving.

The moment you do become conscious of a colour experience, those same underlying mechanisms that unconsciously drove your behaviour become the source of “evidence” for your more explicit phenomenal judgments. That is, as your mind starts looking for a thought or a belief about whether red and blue are the same as each other, the machinery will simply refuse to provide such a justification³.

In his book, Consciousness Explained, philosopher Daniel Dennett sees these two layers — the unconscious/mechanical, and the conscious/phenomenal — as identical:

When we do make these comparisons “in our mind’s eyes,” what happens, according to my view? Something strictly analogous to what would happen in a machine — a robot — that could also make such comparisons.

The sort of difference that people imagine there to be between any machine and any human experiencer […] is one I am firmly denying: There is no such sort of difference. There just seems to be.

Though correct in many respects, Dennett is wrong to deny the phenomenal experience of colours equal rights as mental events of their own, distinct from unconscious, mechanical comparisons of colour. The former require additional judgments, moments of observation, and contemplation. Phenomenal knowledge is an add-on to the stimuli themselves. When you wax rhapsodic about the special feel of a colour, your awareness of this property is always a momentary, additional interpretation, one that takes a special effort of mind. Only by adding onto the original stimulus can you create a range of complicated, nuanced beliefs about colour phenomena. These beliefs extend beyond the raw analytic aspect of colours, and into (synthetic) opinions about them; for example, what the experience of a colour is “like”.

What is a colour “like”?

Once Mary has a tentative grip on the colour and its relation to others, she may soon encounter a new problem — this time a social one. In the course of various conversations, she may at some point want to communicate what red is like to someone else, perhaps to someone who is colourblind and has not had such experiences. She can no longer refer back to the colour itself — that is a dead end. And since colours can’t be broken down, she can’t communicate its parts or properties either. New, linguistic answers must be found: in order to express any answer at all, she must first formulate an answer in her mind as a set of interpretive linguistic thoughts.

Unfortunately for Mary, she is in a difficult position, since red isn’t like anything except itself. The best she can do is try to elicit the feeling she has of the experience in the listener’s mind by proxy or analogy. She wants the listener to empathize with these feelings. Her first instinct would be to search for a thought that appears to cause the same “feelings” that the colour red cause in her, and once found, she will register that as an answer. Of course, as she digs around, she finds the feeling of red isn’t a single identifiable entity. In a given moment, it is whatever feeling is elicited by thoughts of objects that are red — ripe apples, flushed faces, blood, etc. There is no other way to trigger a match. When she describes these in words, and erases their images from the equation, she soon realizes that referring to the red objects themselves is not effective — the feeling of the colour disappears along with the images. So she tries to find some other way to elicit the feeling of red.

Here she will make a category error. The feelings Mary gets when she experiences red will not be about red itself, but rather the concepts associated with those aforementioned red objects — freshness, passion, danger, etc. As discussed in another post, the “feeling” she would describe through those concepts is really the motive behind her interactions with it. Passion, for example, is not a physical object or metaphysical entity, but a motive — namely, the desire to satisfy the unsatisfiable. The serenity of the colour blue is not rooted in a simple association with the ocean or sky, it is a conceptualization of the yearning for relaxing vacations or clear day-trips to the park. (A robot that was afraid of humidity would have a very different stance towards blue, likely one of corrosion and suffocation.)

At a loss for any other alternative, Mary will now erroneously try to elicit the feeling of red by reminding her listeners of the latter concepts. To communicate these concepts, Mary will try to elicit the underlying motive, by thinking up an appropriate story or phrase to inspire passion or serenity. Only on later reflection, and her audience’s push-back, will she realize that this approach is also pointless, since all she has done is communicated those concepts, and not the colour itself. At that point she will simply admit defeat, and give up the project. “Actually”, she’ll say, “there is no way to communicate the qualia of red. It simply is.”

The goal of this post was to show how surrounding motives frame our understanding of colour phenomena. The network of complex needs and desires that go into forming your phenomenal experiences is encompasses the broad diversity of human experience, including social drivers of communication and expression, the need to be trusted and respected, and the desire to understand the world well enough to manipulate and reconstruct parts of it to your benefit. The bewildering kaleidoscope of human phenomenal experience, in all its facets — intellectual, emotional, descriptive — is how your experience of the external world is reflected across the many mirrors of your personal motivations.

In the next and final part of this series we will address the fundamental experience of consciousness itself, and ultimately describe how, and more importantly why people come to understand their own existence.

¹ In general, there are many biological reasons why Mary’s Room is not a viable experiment. Mary’s eyes and visual cortex, deprived of early childhood experiences of colour, may not be able to see colours the way we do, even after being exposed to them.

² The roots of this motive are too complex to get into here; suffice it to say they are derived from a social need to express the experience. It is worth noting here that your own desire to designate things by colour was taught to you at an early age, by parents and teachers asking you to identify them, and by you wanting to please them. Were Mary raised in a room with no colours she may never have been asked to do this exercise, and thus her mind would never raise this request — no more than most adults feel the need to distinguish brands of cars or computers.

³ This implies that it is not possible to be colourblind solely with respect to qualia. If your eyes can detect the difference between red and blue, then the qualia of the two must appear to be different as well.

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From Narrow To General AI
From Narrow To General AI

Written by From Narrow To General AI

The road from Narrow AI to AGI presents both technical and philosophical challenges. This blog explores novel approaches and addresses longstanding questions.

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