First written: Dec 14, 2018, Last update: Jan 2, 2019.

How can we think about the relationship between the conscious and the physical? In this essay I wish to propose a way of thinking about it that might be fruitful and surprisingly intuitive, namely to think of consciousness as waves.

The idea is quite simple: one kind of conscious experience corresponds to, or rather conforms to description in terms of, one kind of wave. And by combining different kinds of waves, we can obtain an experience with many different properties in one.

It should be noted that I in this post merely refer to waves in an abstract sense to illustrate a general point. That is, I do not refer to electromagnetic waves in particular (as some theories of consciousness do), nor to quantum waves (as other theories do), nor to any other particular kind of wave (such as Selen Atasoy’s so-called connectome-specific harmonic waves*). The point here is not what kind of wave, or indeed which physical state in general, that mediates different states of consciousness. The point is merely to devise a metaphor that can render intuitive the seemingly unintuitive, namely: how can we get something complex and multifaceted from something very simple without having anything seemingly spooky or strange, such as strong emergence, in between? In particular, how can we say that brains mediate conscious experience without saying that, say, electrons mediate conscious experience? I believe thinking about consciousness in terms of waves can help dissolve this confusion.

The magic of waves is that we can produce (or to an arbitrary level of precision approximate) any kind of complex, multifaceted wave by adding simple sine waves together.

In this way, it is possible, for instance, to decompose any recorded song — itself a complex, multifaceted wave — into simple, tedious-sounding sine waves. Each resulting sine wave can be said to comprise an aspect of the song, yet not in any recognizable way. The whole song is in fact a sum of such waves, not in a strange way that implies strong emergence, but merely in a complicated, composite way.

Another way to think about waves that can help us think more clearly about emergent complexity is to think of a wave that is very small in both amplitude and duration. If this were a sound wave, it would be an extremely short-lived, extremely low-volume sound. On a visual representation of an entire song file, this sound would look more akin to a dot than a wave.

And such simple sound waves can also be put together so as to create a song (for instance, one can take the sine waves obtained by decomposing a song and then chop them into smaller bits and decrease their amplitude). It will just, to make a song, take a very great number of such small waves superimposed (if the song is to be loud enough to hear) and in succession (if the song is to last for more than a split-second).

The deeper point here is that waves are waves, no matter how small or simple, large or complex. Yet not all waves comprise what we would recognize as music. Similarly, even if all physical states are phenomenal in the broadest sense, this does not imply that they are conscious in the sense of being an ordered, multifaceted whole. Unfortunately, we do not as yet have good, analogous terms for “sound” and “music” in the phenomenal realm — perhaps we could use “phenomenality” and “consciousness”, respectively?

The problem is indeed that we are limited by language, in that the word “conscious” usually only connotes an ordered, composite mind rather than the property of phenomenality in the most general sense. Consequently, if we think all that exists is either music or non-sound, metaphorically speaking, we are bound to be confused. But if we instead expand our vocabulary, and thereby expand our allowed ways of thinking, our confusion can, I think, be readily dissolved. If we think of the phenomenality of the simplest physical systems as being nothing like consciousness in the usual sense of a composite mind but rather as a state of hyper-crude phenomenality — i.e. “phenomenal noise” that is nothing like a song but more akin to a low, short-lived sound, and yet unimaginably more crude still — then the problem of consciousness, as commonly (mis)conceived, seems to become a lot less confusing.**

Avoiding Confusion Due to Fuzziness

A more specific point of confusion the wave metaphor can help us dissolve is the notion that consciousness is so fuzzy a category that it in fact does not really exist, just like tables and chairs do not really exist. As I have argued elsewhere, I think this is a non sequitur. The fact that the categories of tables and chairs are themselves fuzzy does not imply that the physical properties of the objects to which we refer with these labels are inexact, let alone non-existent. The objects have the physical properties they have regardless of how we label them. Or, to continue the analogy to waves above, and songs in particular: although there is ambiguity about what counts as a song, this does not imply that we cannot speak in precise, factual terms about the properties of a given song — for instance, whether a given song contains a 440 Hz tone.

Similarly, the fact that consciousness, as in “an ordered, composite mind”, is a fuzzy category (after all, what counts as ordered? Do psychotic states? Fleeting dreams?) does not imply that any given phenomenal state we refer to with this term does not have exact and clearly identifiable phenomenal properties — e.g. an experience of the color red or the sensation of fear; properties that exist regardless of how outside observers choose to label them.

And although our labels for categorizing particular phenomenal states themselves tend to be fuzzy to some extent — e.g. which part of the spectrum below counts as red? — this does not imply that we cannot distinguish between different states, nor that we cannot draw any clear boundaries. For instance, we can clearly distinguish between the blue and the red zones respectively on the illustration below despite its gradation.

Just as we can point toward a confined range of wavelengths which induce an experience of (some kind of) red in most people upon hitting their retinas, we can also, in principle, point to a range of physical states that mediate specific phenomenal states. This includes the phenomenal states we call suffering, with the fuzziness of what counts as suffering contained within and near the bounds of this range, while the physical states outside this range, especially those far away, do not mediate suffering, cf. the non-red range in the illustration above.

Thus, by analogy to how we can have precise descriptions of the properties of a song, even as an exact definition of what counts as a song escapes us, there is no reason why we should not be able to speak in factual and precise terms about the phenomenal aspects of a mind and its physical signatures, including the “red range” of wavelengths that comprise phenomenal suffering, metaphorically speaking. And a sophisticated understanding of this notional range is indeed of paramount importance for the project of reducing suffering.

* Note that these seemingly different kinds of waves and theories of consciousness can be identical, since connectome-specific harmonic waves could turn out to be coherent waves in the electromagnetic quantum field, as would seem suggested by a hypothesis known as quantum brain dynamics (I do not necessarily endorse this particular hypothesis).

** Another useful analogy for thinking more clearly about the seemingly crazy notion that “everything is conscious” — or rather: phenomenal — is to think about the question, Is everything light? For in a highly non-standard sense, everything is indeed “light”, in that electromagnetic waves permeate the universe in the form of cosmic background radiation, although everything is not permeated by light in the usual sense of visible electromagnetic radiation (wavelengths around 400–700 nm). We may thus think of consciousness as analogous to visible light (they can also both be more or less intense and have various nuances), and electromagnetic radiation as analogous to phenomenality — the more general phenomenon that encompasses the specific one.