
Quantum information in quantum cognition - mathgenius
https://quantumfrontiers.com/2019/05/26/quantum-information-in-quantum-cognition/
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macawfish
Slightly off topic... I was excited to realize that this was by Nicole Yunger
Halpern, who also wrote this interesting paper on quantum voting systems and a
quantum analog of Arrow's impossibility theorem:
[https://arxiv.org/pdf/1501.00458](https://arxiv.org/pdf/1501.00458)

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mathgenius
Some more background from John Preskill:

"The idea that quantum effects could have an important role in brain function
is not new, but is routinely dismissed as wildly implausible. Matthew Fisher
begs to differ. And those who read his paper (as I hope many will) are bound
to conclude: This old guy’s not so crazy. He may be onto something. At least
he’s raising some very interesting questions."

[https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-
to-...](https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-to-know-
whats-going-on-in-my-mind/)

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tabs_masterrace
Here's an interesting lecture on the same subject:
[https://www.youtube.com/watch?v=2_sgFETJzak](https://www.youtube.com/watch?v=2_sgFETJzak)

A lot of hypothesis and speculation in this, but nevertheless very intriguing.
One thing that caught my attention is how the molecular structure of a lot of
common psychedelics (Psilocybin, DMT) have pockets, where quantums are allowed
to be in superposition, and during the process of metabolizing we are
essentially collapsing them.

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codethief
Can anyone with a background in quantum information theory tell me how QI
models the distinction between a quantum system being measured or unitarily
evolved? Nicole Yunger Halpern talks about these things as if the measurement
process were a well-defined thing happening at a specific instant in time. How
and what do quantum information theorists think about the measurement problem
these days?

On another note, having read John Preskill's article
([https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-
to-...](https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-to-know-
whats-going-on-in-my-mind/)) on the whole topic, including his reference to
the zebrafish ([https://www.nature.com/news/flashing-fish-brains-filmed-
in-a...](https://www.nature.com/news/flashing-fish-brains-filmed-in-
action-1.12621)): Assuming that quantum mechanics does influence cognition as
proposed by Matthew Fisher, wouldn't mapping the (zebrafish's) brain then
influence how it works?

~~~
gaze
You treat them as separate things. Kinda. You have the measurement mechanism
and you have the unitary evolution mechanism. There are varying degrees of
sophistication for modeling the measurement mechanism, and there's ways to
have unitary evolution with simultaneous measurement, as well as weak
measurement, and there's systems where you can probe the dynamics of a
measurement. For instance, you can "watch" a quantum jump or even stop and
reverse it (Z. K. Minev et. al. 2018). Generally these things are all modeled
using the Stochastic Master Equation. In the end though, the SME is just
unitary evolution of a small system coupled to a large markovian bath, with a
Bayesian update added. In other words, one could derive the SME by taking an
infinitesimal evolution of the unitary system (coupled to the bath) followed
by an infinitesimal bayesian update, followed by unitary, followed by Bayesian
update, etc. These things are all well covered by Gardiner Zoller 97, and Dan
Steck's quantum optics notes, available at [http://atomoptics-
nas.uoregon.edu/~dsteck/teaching/quantum-o...](http://atomoptics-
nas.uoregon.edu/~dsteck/teaching/quantum-optics/quantum-optics-notes.pdf) .

Some would say that the SME is the fundamental thing, the Maxwell's equations
of quantum information with measurement, and that the instantaneous
measurement you may be familiar with is just a limit of the SME's evolution.
Some might also say that the SME is a thing you derive from weakly coupling a
stream qubits to a system and then performing hard, instantaneous measurement
on those qubits. The math makes no distinction.

~~~
codethief
Thanks a lot for the reference, I will have a look!

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keypusher
This seems fascinating but most of it is way above my understanding. The main
conclusion I got was that “entanglement between phosphorus nuclear spins in
Posner molecules might stimulate coordinated neuron firing”, and that this
could have implications in a wide array of other applications, but requires
further research to be proven true.

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red75prime
Even if evolution wasn't smart enough to use those mechanisms in human brain,
quantum computers can probably take advantage of them.

~~~
vorg
That would mean evolution was smart enough to use those mechanisms in quantum
computers, using human brains as a transient intermediary to that end.

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saagarjha
Also can't really understand what this is, but I seem to have arrived at a
conclusion of this being an answer to "what if we could store quantum
information in the brain's cells and call it 'quantum cognition'". Is there
something else going on?

~~~
macawfish
Theoretically, it's not just limited to brains and neurons! Phosphates are
extremely prevalent in living organisms, and Posner molecules are just a
special arrangement of these common molecules which can prolong entangled
quantum states. For example, from the blog post:

"Posners are believed to exist in us and might participate in bone formation."

And on a slightly different level, from the abstract: "This work opens the
door for the QI-theoretic analysis of biological qubits and Posner molecules."

This could end up being a foundational paper.

