Consciousness is supported by near-critical slow cortical electrodynamics
pnas.org
pnas.org
You could do this with a computer. If your signals coming from the computer are either too regular or too unexpected, then it's probably broken. This sort of thing might be useful diagnostically, but doesn't really provide us with greater understanding...
Imagine if we found that schizophrenia or other potentially debilitating mental health condition were 99.9999% correlated with this signal being weak or strong. That would be telling. If only for diagnosis, and possibly as a cause.
EDIT: a word - "would be telling"
Complex Systems guy: we just showed a system operates in a critical state scale-free phase transition and its key statistics have a power law distribution!
Everyone: okay, so?
CS guy: I dunno? That's what our discipline does. It tells you things are in critical states with power laws. So now you know that...
Cosmologists: we literally took a picture of a black hole!
Someone: So? I already knew they existed. Besides, it's not a picture of a black hole, it's just the ring around the black hole. yawn
Cosmologists: oh... sorry for wasting your time.
From quick skimming, maybe it's some more subtle point in the publication.
Some things that jumped out at me:
> during conscious states, the electrodynamics of the cortex are poised near a critical point or phase transition and that this near-critical behavior supports the vast flow of information through cortical networks during conscious states
But we've had a lot of success building artificial systems that support a "vast flow of information" which I would expect are mostly nowhere near such a boundary. Stuff moves around within a periodic structure, and moving more info has corresponded to moving more information per period. Why would we not expect a pile of neurons with a ginormous number of connections to be able to move a lot of information even through largely periodic behavior?
> we found that the Lempel–Ziv complexity of the model’s simulated electrodynamics (with noise inputs) was maximal when the deterministic component of its dynamics were poised near this critical onset of chaos
I guess if the measure of "information richness" is based in compressibility of electrical activity ... is it surprising that it isn't higher in the chaotic phase? Why wouldn't one expect the chaotic system to produce as much or more random output?
Because neurons as systems don't like random input. Noisy random input doesn't make (most) neurons fire. Rather the opposite, actually.
Neurons aren't (usually) simple threshold comparators of a single input; they're arbitrarily-complex gate-like recognizers, that fire in response to detecting signals in their combined inputs, or even upon matching temporal firing patterns within the signals of their combined inputs.
In that sense, if you tune every component in the system to produce more noise (chaos), you decrease the signal-to-noise ratio, and so the components that react to "important recognizable changes in the signal" within that noise have a harder time recognizing the thing they're looking for, and so they recognize it less, and so switch less.
---
By trite analogy: suppose you're a security guard. Your job is to recognize+report "real crimes in progress", while not reporting "false alarms." (Pretend that the police charge for false dispatches in your town, so your boss wants to optimize shrinkage vs. call budget.)
Also, your boss has decided to "keep you on your toes" by introducing "noise" into your computerized security system. Sometimes it'll show a burglary in progress when there isn't one. Sometimes it'll show that everything's fine, when actually the boss has secretly sent in a white-hat burglar of his own.
How willing to believe the security cameras should you be, to optimize your output signal to downstream demand?
As it turns out, you should probably try to figure out the false-positive vs. false-negative rate you're seeing reported by the downstream, and then calibrate your confidence up/down until you're making a balanced number of Type 1 vs. Type 2 errors. That level of confidence is the "critical point" — where the noise in the system is equally likely to help your detection (by "correcting" a false negative/positive, turning it into a true positive/negative) as it is to harm.
Moving away from that critical point, in either direction, makes your output less useful as a downstream signal.
Chaos can be highly regular. For example, the limiting case of the logistic map, x -> 4x - 4x^2, is chaotic, but also has an exact solution x[n] = sin^2(arcsin(sqrt(x[0])) * 2^n). It's not hard to see why this still obeys the usual properties of Lyapunov doubling etc, but a simple double exponential doesn't seem like the sort of thing that leads to consciousness! From an information-theoretic point of view, the nth bit of x[0] becomes relevant at roughly step n, which means there is a steady "trickle" of information into the system instead of the more complicated dynamics we expect of a "computational" system -- in fact, if we consider the binary expansion of (arcsin(sqrt(x[0]))/pi) we find that only a finite number of bits have an effect on the system's measurable properties at any time, and the effect is rather like scrolling steadily along an infinite tape of random bits.
“Rule 110, like the Game of Life, exhibits what Wolfram calls "Class 4 behavior", which is neither completely stable nor completely chaotic. Localized structures appear and interact in complex ways.”
They increase the average activity of all neurons, so the brain is losing consciousness, because no coherent thoughts can circulate anymore.
And ketamine, the most common pediatric and veterinary anesthetic, has a complex mechanism of action acting on GABA, NMDA, and other receptor systems, often with generally inhibitory characteristics [2] and with definite decrease in brain activity in animal models [3].
[0] https://www.ncbi.nlm.nih.gov/books/NBK430884/
[1] https://elifesciences.org/articles/60824#:~:text=The%20broad....
[2] https://journals.lww.com/anesthesia-analgesia/Fulltext/1998/...
[3] https://www.sciencedirect.com/science/article/abs/pii/002839...
What do you mean by this? Are computers regular? What about a computer programmed to respond to its environment? What do you even mean "respond to environment"? Why does it operate in this mode when awake but not when asleep?
Please, since this research is so obvious to you, I would love to hear your insights on consciousness. They are far beyond mine.
The abstract has more information, describing how this paper adds to the picture a mathematical determination of that critical point, and the insight that low-frequency oscillations play a key role when switching consciousness states.
The level of the experiments is quite high, also they use primates (humans and macaques), some of them epileptic, and they administer psychedelics. All this sets the paper apart from lower-tier work.
It doesn't strike me as a real ground-breaking paper, but still an important contribution to the field. And the methods are impressive.
It looks to me is a huge step, because even the result is so far empirical, the first step to understand anything is being able to measure it.
Imagine someone flipping a switch (in the future where tech to control the electrodynamics exists) and you're awake and aware of your surroundings again.
[1] https://therooster.com/blog/scientists-want-to-give-psychede...
“Unresponsive dude” lol. Interesting descriptor.
It doesn’t sound like anyone has tried it yet.
Yeah, well, you know, that's just, like, your opinion, man.
Sleep could also be an excited incoherent state.
It's hard to describe features of chaos / nonlinear dynamics simply.
There are features of chaotic systems that undergo phase changes from one type of behavior to another. Think a signal on one side of the transition to look like a pure sine wave and on the other side of the transition to look like purely random white noise.
What these guys are reporting is that they found a parameter, a signal they can measure in brains that seems to correlate with consciousness. When the signal is right up near the edge of this kind of chaotic phase transition, the subject is conscious, when nowhere near the phase transition, you aren't. So they have a way to sort of measure and quantify consciousness and perhaps even control it a little by measuring and doing things to manipulate this signal.
It might be sort of like an OPEN sign in a store, just a signal that happens to reflect consciousness, or this brain wave behavior might be a fundamental part of consciousness and higher thinking. It all seems quite interesting.
Projecting guesses out for this is that chaotic dynamics are a fundamental part of how our brains, especially at the highest levels work. One would guess given this evidence and other things that one of the things that makes consciousness possible is a complex system kept balanced at a knife edge of a certain kind of chaotic phase transition. It's also the kind of thing that can open a backdoor for free will in a deterministic universe, your brain in this chaotic state might behave deterministically but the actual state would never be knowable with enough precision to predict the outcome of inputs for any amount of time (butterfly effect).
This reminds me of something Rupert Sheldrake says is possible - that consciousness is 'off-site', that the body is more of a radio receptor.
Consciousness is an emergent phenomenon entirely dependent on and contained within the brain.
brain-as-a-radio-antenna is a common trope amongst those who would believe that meatspace isn't capable of generating consciousness alone (always looking for some sort of elan vital, to equate with another pursuit for the magic stuff of life).
From a purposely scientific perspective, we have to begin with the working assumption that materialism is true, until such point that it is conclusively proven false.
There is no evidence that the brain works in any way like an antenna, at least insofar as any electromagnetic waves or other such messaging systems supported by the physics of our current world as we know it.
Thus, the brain-as-antenna thinking necessarily pre-supposes an other-worldly explanation; it assumes what it's trying to prove.
Even if it were true (HIGHLY unlikely), we can't begin with that as the starting point in our search for understanding it. Otherwise, our brains are incredibly adept at shaping our thoughts and concepts to fit those prescribed notions of animacy and otherworldliness.
It's no wonder that many pseudoscientific principles BEGIN with the presupposition that you have to be willing to believe in order for the effect to become apparent.
Materialism, aka "physicalism", simply posits that all phenomena have an underlying physical basis, i.e., no "spooky" or magic stuff.
https://plato.stanford.edu/entries/physicalism/
Quantum mechanics follows from physicalism by demonstrating that the physical nature of reality is incredibly complex and counterintuitive, particularly at quantum scales.
But that in no way implies that quantum mechanics leads to non-materialism or opens the door for materialism to be false. It simply becomes subsumed into materialism itself:
materialism requires that all phenomena be ultimately explainable via physical explanations, and those explanations must account for quantum-mechanical phenomena.
If you shut off all outside signals, the brain works just fine, there's no effect at all. (Except maybe the stress of whatever situation you're in that landed you in a super shielded bunker. )
Materialism does the same thing though, as you observed:
> we have to begin with the working assumption that materialism is true
To be clear, I'm a materialist, but that's precisely why I dislike poor arguments.
How would one falsify this?
Consciousness exists. It ceases to exist when the brain is damaged or killed. We can predictably modify conscious systems with drugs and experiences. Particular types of injury and illness sometimes result in predictable consequences, letting us know things such as that the hippocampus is critical to memory, and that whatever hierarchy of semantic meaning is stored in the brain, neurons in the hippocampus represent ontological peaks in the mental landscape of constructed meaning.
With a sufficiently high resolution brain interface, you could record, replay, simulate, and share experiences between consciousnesses. If the mind is an emergent phenomena brought about within the confines of the skull, shared experience will be possible, up to the point that your subjective experience of being another person will be complete for the duration of the replay. If there's some outside factor playing a role in consciousness, it will be missing and likely prevent attempts at recording experience.
Using the radio metaphor, I think I could edit the radio so that the signal would be heard differently. Just turning up the volume is a sort of alteration of consciousness, as would be increasing/decreasing the bass/treble.
These are alterations to the way the sound is experienced, but do not affect the signal itself.
Maybe taking drugs would be akin to running the received signal through some sort of special effects board? Ie a different/unusual type of alteration to the signal.
I think all it would mean is that the human brain is non-deterministic.
That’s different from free will though which is really an untestable, philosophical idea rather than a testable scientific hypothesis.
In any event, a random chaos state can be both non-deterministic and not intentional, or what many would call “free will”.
Chaotic systems are still deterministic. They're just extremely sensitive to their initial conditions/inputs.
For example, is a chaotic system that depends on initial conditions so precise that having adequate measurement to predict the outcome would violate the uncertainty principle still deterministic?
That we can't have all knowledge about most systems in the real world doesn't mean they're not deterministic.
And who knows what kind of magical science we'll find in the future that turns everything we know about measurement upside down?
Is there some definitive proof for this, or are we just taking it as a useful assumption?
"chaotic systems" aren't just... unpredictable things that we find laying around and say "yeah we'll call that chaotic because it looks like my kid's bedroom". they've got to satisfy that description.
If you can QED me to a conclusion that yes, in fact, the sun will rise in the morning, I would genuinely find that useful.
sounds like you tried to take a flying leap away from the mathematically sound, and pedestrian statement of darawk into philosophy. you should warn people about that, so that people know not to bother.
> If you can QED me to a conclusion that yes, in fact, the sun will rise in the morning, I would genuinely find that useful.
if "gravity" isn't enough of an answer for you, then nothing can ever be.
Nice word. Does it have a definition?
> There was never room for any non-deterministic thing to magic itself into the system
Depending what you mean by "into the system," existence itself is a glaring counterexample.
How did any of it get here in the first place? Was there an uncaused cause? Is entropy reversible?
Until we can explain-away these types of questions, it'd be prudent to remain noncommittal on the topic. The type of determinism that sigstoats expect might not even make sense in other regions or eras of reality. Things get profoundly hazy past Planck Era.
Regarding existence itself, I agree that determinism is not an exhaustive set of possibilities (if it was, it would imply an infinite chain of causes, which presents its own problems). I just challenge the idea that one can possibly get a non-deterministic system if we assume that we're working with purely deterministic components/rules.
Whatever the Big Bang event was, I'm assuming it was a result of some exterior nature.
What I worry about is whether or not its even possible to connect the dots between the two.
Gödel's second theorem may just straight up make this whole exercise pointless.
Just imagining that outcome gives me the urge to primal scream.
All I know for certain is I've got a lot of questions.
b) Unlike matter and energy, information complexity does not obey laws of conservation. (Demonstrably so.)
c) Ergo, an information complexity singularity can exist, and if it does - we would be reasonably correct in calling it "free will".
Either the things in our brains follow deterministic patterns or they're random. Neither one of those gives me room to decide to get a glass of orange juice. In fact, any desire I have at all for an orange is dependent on that type of plant having emerged billions of years ago. I can imagine a fruit that doesn't exist, but I can't desire it and I can't buy it at the store. I had no say in any part of that causal chain whatsoever.
... but of course that gets us no closer to a definition. If someone can come up with a sensible definition, it could be interesting, certainly.
Hmm, what about predictability conflicts with the idea of free will? Just because my actions are predictable doesn't mean they aren't a reflection of my will. It seems to me that the opposite is true, there is no coherent "you" if your actions aren't based on a consistent set of rules since that implies how you behave ultimately has no connection to who you are. To escape determinism means to become literally insane.
It really doesn't, because free will implies control over one's choices. Randomness, non-determinism, etc. doesn't provide that, and I bet you can't describe a way in which it could.
At least that's my current understanding of the matter, coming from the mouth of an undergrad late in a biochem degree with a focus on neuro
https://en.wikipedia.org/wiki/Critical_exponent
The concept of phase transition is broader than the phases of matter.
At low differentials there’s no convection just conduction, as you raise the temperature difference you get a stable single circulation loop which is well behaved, continue further and you get a tempest of circulations coming and going in an entirely unpredictable manner.
There are distinct phase transitions between each of these states.
Another one is a forced double pendulum. With just a little periodic force they swing gently back and forth, with a lot they do constant crazy unpredictable loops around each other.
https://mitpress.mit.edu/books/dynamical-systems-neuroscienc...
* A mathematician explains what Foundation gets right about predicting the future (spoiler: critical points!): https://www.sciof.fi/a-mathematician-explains-psychohistory/
And if you're still interested, there's a more in-depth explanation with mathematical formulas and all. Even if I understood only 10-20% of what Ken Wilson was talking about, he gives a lucid motivation for why critical points are important and why they can be found in practice using renormalization groups, and not computer simulations:
* Ken Wilson's Nobel Prize lecture: https://www.nobelprize.org/uploads/2018/06/wilson-lecture-2....
The problem with consciousness is that the only evidence it exists is that individuals claim to experience it, without even really defining what it is they experience. This "evidence" has a much simpler explanation than the existence of an almost-magical consciousness.
It's not that there can't be something like consciousness, but there is currently nothing to indicate this.
Why do people feel the need to continuously push this fake science?
Point to one, please.