However, we don't have any reason to suppose that quantum computation is involved or relevant in any of the processes mentioned in the article, and we don't really have any evidence or reason to suppose that the brain is a quantum device. It might be one, but for all that we've seen until now it might as well be an electrochemical computer, that is sufficient to explain all observed phenomena.
I both like and dislike theories of mind that describe the brain in terms of n-veiled solipsism. But I generally like them because of the specific (decision-theoretic) statements they make about how an agent is defining its environment.
What's striking to me about life on earth -- mostly humanity, but also the larger notions of noo-/biosphere -- is that, so far, it doesn't match up to our larger-scale evidence about how <things in general> define <their environments>.
We have managed to define our environment in a fashion which is scale-agnostic, at least with respect to the measurement of physical accumulations of stuff. We readily form metaphors between:
(a) things in our locale,
(b) things in the huge,
(c) things in the tiny, and
(d) things in the meta (read: math/pattern).
I think the worst thing we can do -- as engineers or scientists or mathematicians or even metaphysicians -- is to presume that any of |a-d| generate the others "in reality". (I just did a bit of that when I implicitly defined "larger-scale evidence" as "most legitimate evidence".)
In the categorical sense of arrow-reversal-without-structural-change[0], models of |a-d| are dual to any notion of 'environment' we can imagine. That doesn't suggest determinism, but it does offload every variation on the question of free will into a(n empty) simulationist argument whose limit is some computational infinity, like an omni-* deity or an extremely general structure like an ∞-topos[1].
An interesting partial exception is complexity theory. When we map out statements like PostBQP==PP[2], we're doing something fundamental, that bridges the gaps in |a-d| without adding something too weird as |e|. The actual notion of 'complexity-wise truth' that's being generated[3] is a measure of inferential distance that doesn't seem to care about pesky details but is somehow still attuned to specific problems.
There are caveats -- you could imagine each distinct problem/distance class as the dual of a scope (our syntactic presentation of such scope anyway[4]). The segregation of our environment into such scopes is only the first half of the problem. Less trivial is the act of mapping out our environment as a structured space of such scopes, so that we dissolve all questions of type ['what is', 'what should be', 'what was', etc.] into a singular question of type ['what direction to go now'].
To me, this sounds quite dangerous. And yet some variation on that is what many of us in the greater "self-directed tech" milieu are working on. There's an embedded urgency to the framework. Call it "the market" or "the simulation" or "the basilisk" or "bringing about the singularity" or "humans vs. ai" or "geopolitics" or whatever you want, but what's difficult to ignore is how effectively |bcd| equivalences eat up |a|, for any definition of |a| that invites historical norms.
Interpret this how you will.[5] For me it causes a sharp recoil from generalizations like "we are just the universe observing itself." The recoil is followed by a question, "okay what should I observe so that I might identify with it?" To which the answer is usually, "whatever makes me a better engineer, so that I can worry about this later, when I have a better understanding of what I'm asking." (i.e., I fail to prevent |bcd|>|a|, and each iteration on the theme speeds up the process a little bit.)
[0] https://ncatlab.org/nlab/show/duality
[1] I should say I feel pretty awful making this analogy, as it performs a |bc| equivalence at the expense of most of |a| and everything important in |d|. It's no better than "what if atoms are tiny universes?"-type questions, and it should be treated as illegitimate as evidence for anything more detailed than the notion of existence itself.
[2] http://blog.computationalcomplexity.org/2004/01/complexity-c...
[3] https://complexityzoo.uwaterloo.ca/Complexity_Zoo
[4] https://golem.ph.utexas.edu/category/2010/07/what_is_a_theor... (though this analogy is almost worse than [1]'s)
- 15th century: the brain is the creation of a divine being
- 17th century: the brain is a clockwork
- 20th century: the brain is an electrical computer
- 21th century: the brain is a quantum device
- 22th century: the brain is a ??
It's an interesting thought though, and I especially like Neil Stephenson's idea that the brain is a quantum device that 'leaks out' into parallel universes and uses 'brain capacity' from those overlapping universes, but it's just that: a neat idea, and science fiction. What's different this time? :)
[edit: formatting]