Quantum Biology and the Hidden Nature of Nature

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  • #26
Q_Goest
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You say "coherent neuronal oscillations", I say "electrical activity of neurons" - but we are essentially talking about the same thing. Chemical synapses aren't the only thing involved - hormones from the bloodstream, genetic processes affecting receptor density and distribution, electrical synapses which allow for much faster coupling than chemical synapses, second messenger systems that change the electrical properties of the neuron by increasing the conductance through a receptor or changing the kinetics of the votage response of the receptor.
I like this point. There seem to be a number of different perspectives on or descriptions of the activity between neurons. Those phenomena produced from the interactions should in principal, arise from the local interactions between neurons as described by Hodgkin, Rall or whoever, regardless of which way you want to look at or describe the interactions. If the interactions between neurons are classical in nature, they are separable, so phenomena such as “coherent neuronal oscillations” should emerge regardless of which description you choose of those interactions.

Self organization is something which arises from local interactions. It’s also defined by “weak emergence”. Assuming neurons don’t exploit any of the special features of quantum mechanics, then downward causation can’t influence the brain as a whole. Since there’s no reason to accept that the brain as a whole is some kind of quantum computer, there’s no reason to accept that local interactions are insufficient to produce all of the phenomena produced. The interactions between neurons are 'calculated' using software like "Neuron" and "Genesis" and if you look at those software, you will find they are consistent with weak emergence and self organization so they should produce all the same phenomena (in principal) as actual neurons regardless of how you want to describe those interactions.
 
  • #27
Pythagorean
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Thanks Pythagorean, but the cited material is presentation and not a publication which can be read. Is it related to the work by Gollo et al. [1] ? If so then I have to question the results. The methods used solve differential equation based models of neurons (Hodgkin-Huxley) using Runge-Kutta based methods. This is an iterative method that implicitly assumes sychronized updating a priori, so I don't find the results surprising. You wouldn't get these results with an asynchronous updating method. This comes back to the question of where the synchronization comes from.

[1] Gollo LL, Mirasso C, Sporns O, Breakspear M (2014) Mechanisms of Zero-Lag Synchronization in Cortical Motifs. PLoS Comput Biol 10(4): e1003548. doi:10.1371/journal.pcbi.1003548

Step sizes for the Runge Kutta algorithm are much much smaller than the mechanisms of synchrony so that they can be taken to be continuous; this is a rather basic ptinciple in numerical analysis. You can test the stability of your functions and choose an appropriate algorithm if RK doesn't work. But besides that, there is also experimental evidence. Synchronization via typical neuronal mechanisms isn't exactly controversial. None of the mechanisms are impossible in the large scale, we just don't have the fMRI resolution to determine what mechanisms are playing what role.

@Q_Goest

Hodgkin Huxley would be appropriate for certain types of neurons for a short time scale, but you'd have to make adaptations to the model to consider hormonal and genetic changes. In fact, the HH model doesn't even include a synapse. It is only an axon membrane. Of course, it still does all imply weak emergence as, you say. All these adaptations have been made in various forms. My own research includes a lot of second messenger modulation on kinetics.

I'm not sure how well we can compare simulations to a real brain. The brain is doing a lot of fantastic things, the computer is flipping registers around and generating an abstract symbol that we interpret in a relevant way. It's just a very sophisticated note pad and pen. To generate consciousness then, our best bet would be to physically reproduce the brain as best as possible.

It would be nice to see the results of some of the popular thought experiments. What happens if you replace a conscious human's brain one neuron at a time? What happens if you separate the neurons spatially while keeping the information processing the same?

My prediction for the first is, of course, nothing. The second is interesting: if separating the components destroyes consciousness, I'd be inclined towards an electromagnetic field theory of consciousness. If not, then we have to stick to the information theory approach.
 
  • #28
.Scott
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Since there’s no reason to accept that the brain as a whole is some kind of quantum computer, there’s no reason to accept that local interactions are insufficient to produce all of the phenomena produced.
There is a reason to accept that the brain employs quantum superpositioning to process information. It's easy to explain - but perhaps not so easy to understand. In order to be conscious of something, the information describing that something has to be in one state - not divided into discrete symbols. Classical information processing doesn't provide a mechanism for that.
 
  • #29
Pythagorean
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There is a reason to accept that the brain employs quantum superpositioning to process information. It's easy to explain - but perhaps not so easy to understand. In order to be conscious of something, the information describing that something has to be in one state - not divided into discrete symbols. Classical information processing doesn't provide a mechanism for that.

That's kind of begging the question isn't it? What is the reasoning that "In order to be conscious of something, the information describing that something has to be in one state"?
 
  • #30
.Scott
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That's kind of begging the question isn't it? What is the reasoning that "In order to be conscious of something, the information describing that something has to be in one state"?
Obviously the character string "tree" is not enough (or the right kind of) information to sustain the conscious experience of a tree - but let's use it as an example anyway. If you had four neurons, each with one of the letters, which neuron would have the experience of "tree"? In order for "you" to be conscious of "tree", there has to be one place that has all the information.

If you write "tree" on a piece of paper, obviously there is no consciousness of "tree" because the information is divided. You can make the paper as small as a neuron, but it won't help. You can process the information - reencode it, photocopy it, etc - but none of that will create a situation where the entire "tree" is in one state - and so there is no place for the "tree" experience to exists.
 
  • #31
Pythagorean
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In order for "you" to be conscious of "tree", there has to be one place that has all the information.

What experiment determined that?
 
  • #32
.Scott
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"In order for "you" to be conscious of "tree", there has to be one place that has all the information."
What experiment determined that?
I thought the statement made before this demonstrated it: "If you had four neurons, each with one of the letters, which neuron would have the experience of "tree"?".
What kind of experiment would prove or disprove this? It's a fundamental statement of locality.
 
  • #33
Q_Goest
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In order to be conscious of something, the information describing that something has to be in one state - not divided into discrete symbols. Classical information processing doesn't provide a mechanism for that.
Hi Scott, Just to clarify, when I said, "... there’s no reason to accept that local interactions are insufficient to produce all of the phenomena produced." I mean that classical mechanics (ie: local interactions which are separable as defined in philosophy of science) between neurons is sufficient (to produce oscillations, etc...). I don't mean that classical mechanics is up to the task of explaining p-consciousness. Let's accept that neuron interactions don't utilize any of the special features of quantum mechanics and move on from there. I would disagree that's a dead end.

The argument that 'classical' information can't provide a mechanism for p-consciousness has been written about by a few authors. I think I'd listed a few earlier. Below are two more. There are others. Pythagorean has eluded to field theories which attempt to introduce quantum mechanical interactions across the entire brain such as by Pocket and McFadden. However, there's a complicated line of logic that's needed to support the contention that classical mechanics can't provide a basis for p-consciousness and I don't see any papers that have provided that logic in a way that everyone can accept.

Note the two authors below would agree that there's no quantum mechanical interactions between neurons. Edwards suggests single cells are the fundamental units of consciousness without providing much in the way of a logical argument. Sevush jumps right to the conclusion and provides even less of an argument why than Edwards. I personally believe there's a great argument out there having to do with separability but there are as many other arguments that suggest otherwise.

The bottom line is that this forum isn't set up for and doesn't support philosophical discussions around this topic, primarily because people tend to 'shoot from the hip' with their own pet theories without referencing the published literature and without knowing much about what's already been written.

Edwards, J. C. (2005). Is consciousness only a property of individual cells?. Journal of Consciousness Studies, 12(4-5), 4-5.
Sevush, S. (2006). Single-neuron theory of consciousness. Journal of theoretical biology, 238(3), 704-725.
 
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  • #34
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Step sizes for the Runge Kutta algorithm are much much smaller than the mechanisms of synchrony so that they can be taken to be continuous; this is a rather basic ptinciple in numerical analysis.

Yes, numerically I understand this, but what is the physical basis for this assumption in a biological system? Updating methods can have a serious effect on observed phenomena [1]. Wouldn't choosing smaller step sizes imply that faster processes (i.e. molecular interactions) are synchronized? What is the physical rationale for this? Why is it safe to assume that the faster processes are synchronized?

[1] Cornforth, D., Green, D. G., Newth, D., & Kirley, M. (2003). Do artificial ants march in step? Ordered asynchronous processes and modularity in biological systems. In Proceedings of the eighth international conference on Artificial life, MIT Press (pp. 28-32).
 
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  • #35
.Scott
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Let's accept that neuron interactions don't utilize any of the special features of quantum mechanics and move on from there. I would disagree that's a dead end.
I tend to agree - but I'm not as certain as you. There are obvious difficulties with having any QM data processing in a wet and warm environment. The problems get more difficult, and probably insurmountable, when you try to communicate entanglement from one cell to another. In the other cases we know of where QM processing may be active in living tissue, it happens at the molecular scale. In the video introduced in the OP, Seth Lloyd also pointed out that in both of those cases, photons in the visible range were available to provide a burst of energy - something he cited as being potentially instrumental in allowing QM to be effective for an instant.

The argument that 'classical' information can't provide a mechanism for p-consciousness has been written about by a few authors. I think I'd listed a few earlier. Below are two more. There are others. Pythagorean has eluded to field theories which attempt to introduce quantum mechanical interactions across the entire brain such as by Pocket and McFadden. However, there's a complicated line of logic that's needed to support the contention that classical mechanics can't provide a basis for p-consciousness and I don't see any papers that have provided that logic in a way that everyone can accept.
A paper that everyone can accept is a long way off. For me, it appears to be direct observation - although I didn't make that observation until I had been programming computers for several years. Until we find one of the neurons that does the QM processing, identify exactly what the process is (I'm suspecting a variation of Grover's Algorithm), and show that that's what the neuron is doing, we won't have acceptance from "everyone".

Note the two authors below would agree that there's no quantum mechanical interactions between neurons. Edwards suggests single cells are the fundamental units of consciousness without providing much in the way of a logical argument. Sevush jumps right to the conclusion and provides even less of an argument why than Edwards. I personally believe there's a great argument out there having to do with separability but there are as many other arguments that suggest otherwise.
I will check them out. As a software engineer trying to get into a large undocumented system, I try to identify essential elements of the process that have to be there - then I locate the code that performs those functions and work my way out from there. So that's what I do with consciousness. Since we can talk about it, it has to be part of our decision-making process. So the question becomes why would we use QM processing to process the type of information that we are conscious of to make a decision?

The bottom line is that this forum isn't set up for and doesn't support philosophical discussions around this topic, primarily because people tend to 'shoot from the hip' with their own pet theories without referencing the published literature and without knowing much about what's already been written.
I am interested in the mechanics. And as you may have noticed, I have little interest in the philosophical aspect of this. I have read up on the philosophy - and it impresses me as many distinctions with no differences. From a physics point of view, two systems which, in principle, cannot be distinguished from each other are equivalent.
 
  • #36
Evo
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There have been a lot of good posts, some people are good about providing citations, others not, and too much philosophical discussion has been interjected. As such, the mentors have decided it is time to put the thread to rest.
 

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