4 ms·

Quantum information in quantum cognition

44 points by mathgenius 7y ago

keypusher 7y ago
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.
saagarjha 7y ago
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 7y ago
  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.
- amelius 7y ago
  I'm not sure this is all very significant. It's good to remember that the transistors in your computer are based on quantum mechanics as well ...
- zamalek 7y ago
  There are also a few interesting interactions with that stored QI: * QI can be retrieved from Posners (into neurons via neurotransmitters). * QI can be teleported between Posners, while suffering noise. * Quantum error detection can be solved with Posners. * Most importantly, Posners can participate in quantum computation. "Posner operations can prepare a state that fuels universal measurement-based quantum computation."
macawfish 7y ago
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
mathgenius 7y ago
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-know-whats-going-on-in-my-mind/ https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-to-...
red75prime 7y ago
Even if evolution wasn't smart enough to use those mechanisms in human brain, quantum computers can probably take advantage of them.
- vorg 7y ago
  That would mean evolution was smart enough to use those mechanisms in quantum computers, using human brains as a transient intermediary to that end.
tabs_masterrace 7y ago
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.
codethief 7y ago
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-know-whats-going-on-in-my-mind/ https://quantumfrontiers.com/2015/11/06/wouldnt-you-like-to-...) on the whole topic, including his reference to the zebrafish (https://www.nature.com/news/flashing-fish-brains-filmed-in-action-1.12621 https://www.nature.com/news/flashing-fish-brains-filmed-in-a...): Assuming that quantum mechanics does influence cognition as proposed by Matthew Fisher, wouldn't mapping the (zebrafish's) brain then influence how it works?
- krastanov 7y ago
  Most QI professionals do not worry about the philosophical "measurement problem", because it does not matter in their daily work (the math just works). However, it is certainly interesting and it might end up being important for the foundations of quantum mechanics. By the way, here is something you might want to look up: in the context of Lindbladian (non-unitary) evolution or in the context of weak quantum measurements, the measurement problem is not particularly obvious or disturbing. At the end it is still there, but these toolkits give you a way to reinterpret it as an uninteresting detail of the theory, not as a horrible stain.
- mathgenius 7y ago
  > the distinction between a quantum system being measured or unitarily evolved When you try to describe a part of an entangled quantum system, independently of the whole, you will be forced to use probabilities in your description. This is quantum measurement.
  - codethief 7y ago
    I don't think I would call this a "measurement". A measurement, in the Copenhagen interpretation, is a fundamentally non-unitary process. What you're describing is simply tracing out the environment, so that we end up with a mixed state. The complete density matrix, however, is still being governed by the Von-Neumann equation and therefore evolving unitarily. So I assume what you're saying is that we don't need to model measurements separately since their results would be described by statistical ensembles and, at the level of a subsystem, you can't really tell the difference between a genuinely entangled state and a statistical ensemble, anyway?

44 points by mathgenius 7y ago

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.

saagarjha 7y ago

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 7y ago
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.
amelius 7y ago
I'm not sure this is all very significant. It's good to remember that the transistors in your computer are based on quantum mechanics as well ...
zamalek 7y ago
There are also a few interesting interactions with that stored QI: * QI can be retrieved from Posners (into neurons via neurotransmitters). * QI can be teleported between Posners, while suffering noise. * Quantum error detection can be solved with Posners. * Most importantly, Posners can participate in quantum computation. "Posner operations can prepare a state that fuels universal measurement-based quantum computation."

macawfish 7y ago

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

mathgenius 7y ago

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

red75prime 7y ago

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

vorg 7y ago
That would mean evolution was smart enough to use those mechanisms in quantum computers, using human brains as a transient intermediary to that end.

tabs_masterrace 7y ago

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.

codethief 7y ago

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

krastanov 7y ago
Most QI professionals do not worry about the philosophical "measurement problem", because it does not matter in their daily work (the math just works). However, it is certainly interesting and it might end up being important for the foundations of quantum mechanics. By the way, here is something you might want to look up: in the context of Lindbladian (non-unitary) evolution or in the context of weak quantum measurements, the measurement problem is not particularly obvious or disturbing. At the end it is still there, but these toolkits give you a way to reinterpret it as an uninteresting detail of the theory, not as a horrible stain.
mathgenius 7y ago
> the distinction between a quantum system being measured or unitarily evolved When you try to describe a part of an entangled quantum system, independently of the whole, you will be forced to use probabilities in your description. This is quantum measurement.
- codethief 7y ago
  I don't think I would call this a "measurement". A measurement, in the Copenhagen interpretation, is a fundamentally non-unitary process. What you're describing is simply tracing out the environment, so that we end up with a mixed state. The complete density matrix, however, is still being governed by the Von-Neumann equation and therefore evolving unitarily. So I assume what you're saying is that we don't need to model measurements separately since their results would be described by statistical ensembles and, at the level of a subsystem, you can't really tell the difference between a genuinely entangled state and a statistical ensemble, anyway?