That's cool! Can you say more about how the experiment worked?
During my Ph.D, I would often spot this on my way to the lab. I would be seated in the subway early in the morning, and suddenly realize that the name of a station had just been announced, but that I hadn't heard it. Then, it was suddenly like I had heard it -- as if the trace sensory signal in auditory cortex had been isolated and amplified by my attentional system, before it fully dissipated.
It was (and still is) super cool.
I use similar techniques (plus muscle memory, visual, etc.) as a short term memory scratch pad - especially when highly sleep deprived.
Here's a pure psychophysics study we performed. It gets at the essence of the mechanism without forcing you to wade through pages of fMRI-related esoterica.
I'm happy to answer any questions :)
I've had a tiny bit of experience dealing with the visual system in a related but distant field (the feedback loops of visual accommodation and vergence and conflicts that can emerge with stereoscopic 3d - and I wish I had understood and done actually insightful things..). This left me wondering about the important place of vision-based experiments in the theories of perception as well as consciousness. What are your thoughts about that subject? For example, would similar research be doable with other senses just as well, or is that something that we have a harder time grasping or even formulating (due to a certain bias towards vision) ?
edit: I've read the other comment about the double-take so in this case there seems to be some ways to test that out on other senses, but my question still holds when talking about the overall field and the prevalence of vision in this kind fo research
Yes, very much so! I believe there is less bias towards vision than you think. Once you have a paradigm that works in vision, replicating it in other sensory modalities is generally low-hanging fruit for subsequent publication. I didn't get the sense that consciousness research was terribly biased towards vision. The fields of audition and haptics are alive and thriving.
Here's an experiment I did with MEG in the auditory domain:
http://www.unicog.org/publications/Marti%20Thibault%20Dehaen...
So your point is far from crazy. However, there is sufficient multi-modal evidence that I don't think our current theories of access consciousness are mere visual artifacts.
If I'm being facetious, I don't :P
More seriously, my reading of Chalmers is not that neural correlates of consciousness don't exist per se, it's rather that
1. So-called "access consciousness" (i.e. consciousness in the sense of "I am conscious of X") is distinct from phenomenological consciousness (contrary to what Dennett thinks).
2. Further, access consciousness has very little to do with phenomenological consciousness, to the point that calling it "consciousness" is a misnomer.
3. Therefore, neural correlates of access consciousness will never give us insight into phenomenology.
I think my position is that of most people in the field. I'm agnostic. Or more exactly, damned if I know what I think about that. I find it hard to believe -- as Dennett claims -- that once we've explained everything about neural correlates of (access) consciousness, that there will be nothing left to explain. I also find it hard to believe Chalmers' story that neural correlates have nothing to teach us about about phenomenology. But my arguments ultimately appeal to an interpretation of scientific data in the context of my own experience, so it's really a gut feeling of "neither seems quite right".
Given this, my stance is basically "I don't research hard problems; I research easy problems". Access consciousness -- whatever that is -- is interesting and useful to study. I choose that.
(N.B.: most of this should be written in the past tense, as I have now moved to a different field!)
Ok, so you have a "Zombie" that has all the behaviors and physiological processes associated with access, but no qualia.
In principle, we might learn everything there is to know about access and still have no insight into qualia. Have I summarized that correctly?
Assuming so, my position with respect to "why study neural correlates" is:
1. Access (whatever that is), is still interesting and worth studying, if only to find out what it actually is, and even if it's "just" working memory or attention.
2. At the very least, we will have succeeded in distinguishing access from phenomenology. Our common human understanding of (phenomenal) consciousness will have advanced insofar as we will understand it to exclude access and all its second-order effects.
3. It remains to be proven that there is something more to explain than "just" the physiology and intentionality of brain processes with respect to access. If there is, Chalmers might be right. If not, the point goes to Dennett -- and think about the implications!
[0] https://edwardfeser.blogspot.com/2011/01/against-neurobabble...
Where? In the USA? Indubitably.
In France? Definitely not.
So Dennett, Hofstadter, Edelman et al, while really smart, will never get an inch closer to a true explanation.
The mechanism by which general anesthetics temporarily and partially/fully disables consciousness should provide a nice hint in which direction a true explanation should go.
There is no doubt imo that the theory will be based on quantum mechanics. Roger Penrose goes even a step further and states that the theory needs a non-computational component. (see Orch Or : https://en.wikipedia.org/wiki/Orchestrated_objective_reducti... )
In any case, I'm still waiting on an Einsteinian admission from most scientists that it is "their biggest mistake" to consider that a "warm, wet and noisy" environment like the brain cannot host the necessary quantum phenomena. In the current state of affairs, they have been proven wrong already.
Eesh, this again ...
There has never been a proposed (serious, testable, much less supported) mechanism by which quantum mechanics could explain consciousness. This argument always boils down to "phenomenology happens in the mysterious place". Quantum mechanics is the 21st century pituitary gland.
>In any case, I'm still waiting on an Einsteinian admission from most scientists that it is "their biggest mistake" to consider that a "warm, wet and noisy" environment like the brain cannot host the necessary quantum phenomena. In the current state of affairs, they have been proven wrong already.
We are all convinced that quantum-mechanical phenomena can take place in microtubules. That debate is settled, but here's the thing: that was never really the issue. The issue was -- again -- that none of these theories explain how phenomenology emerges from quantum mechanics. All they say is "it does".
EDIT:
>People like Descartes, Helmholtz, Ryle, Dennett, Searle were/are stuck in the framework that tries to explain (while it provides no explanation at all) consciousness as an emergent property of a complex enough computation (by neurons).
This, however, is a statement on which we agree. This is why most consciousness researchers set their sites lower: they aim to explain access consciousness, and take no position on phenomenology. In other words, we're displaying humility by asserting knowledge of the easy problem, not the hard one.
Yes, the HN crowd surely loves to downvote these type of posts. You're the compassionate scientist who has seen this layman's argument too many times. The brain is mysterious, consciousness is mysterious, QM is mysterious, bingo, QM will explain consciousness. Well, that's not what I, as a layman, meant. What I meant was Orch-OR and it is at least a good starting point.
>That debate is settled, but here's the thing: that was never really the issue.
It's still an issue but not in the way you see it. Behavior of microtubules is subject to phenomena like quantum coherence. Microtubules help move mitochondria in the axons. Mitochondria in the axons help suppress or enhance neurotransmitter release. So qm phenomena have a direct effect on the formation of thought. Please let me know If i'm talking nonsense :).
>In other words, we're displaying humility by asserting knowledge of the easy problem, not the hard one.
You've given up already. I believe we can find a plausible explanation for consciousness. The mainstream theory is an absolute non-explanation, and a dead-end.
Very well, I shall look again, but color me (extremely) skeptical. Are you able to propose a mechanism by which quantum mechanics can explain qualia?
I have yet to see even a partial mechanism. The issue is that qualia specifically involves something non-mechanistic. You would have to first qualify what the substance of qualia is (it's ontology ... and good luck with that!), how it emerges from quantum-mechanical phenomena, and whence it comes (where is the stuff of qualia when it's not manifesting?).
Again, I don't (yet?) see how any mechanistic explanation can explain this.
>Please let me know If i'm talking nonsense :).
It's not nonsense per se, but none of it addresses the key criticism. You must explain how that causal chain (microtubules -> mitochondria -> neurotransmitter) produces qualia.
Your argument is effectively that microtubules can influence the creation of thought. Great! So can neurons! So can drugs! So can a blow to the head! Why insist on microtubules?? Why not elsewhere?
>You've given up already.
I've also given up on proving the existence of God!
Less facetiously: phenomenology has the advantage of being self-evident. We're all pretty much convinced that it exists, contrary to God. Given that, and given the advances in materialist philosophy, it's not prima facie crazy to suspect that phenomenology is a physical process, and therefore amenable to scientific explanation. In this, you have a point.
However, I don't think science (or philosophy for that matter) currently has the ability to propose an explanation for how some process p implements qualia. We don't even know what such a theory would look like. As such, the quantum-mechanical argument really does seem like the pituitary gland of the 21st century.
>The mainstream theory is an absolute non-explanation
Which mainstream theory? Are you referring to access consciousness? If so, then you are basing your argument on a false premnise, namely that these scientists are investigating the same thing as you. They are not. They are interested in another thing we call consciousness, which may or may not be related to the phenomenological consciousness that you are interested in. It's still an interesting question.
If you're referring to mainstream theory of phenomenology (e.g. sensorimotor theory), it is at the very least no more absurd than quantum-mechanical theories.
>Yes, the HN crowd surely loves to downvote these type of posts.
Respectfully, have you considered the possibility that your ideas just don't add up? I mean no disrespect, and again will take another look (links welcome), but I notice that you have not addressed the central question of how a mechanism (let alone yours, specifically) can produce a qualia. I suspect this is what motivates the downvotes.
That's awesome, thank you! Ultimately it's beneficial to keep an open mind on things about which one is skeptical or even convinced the idea is rubbish (well, some are of course).
>Are you able to propose a mechanism by which quantum mechanics can explain qualia? Again, I don't (yet?) see how any mechanistic explanation can explain this.
No, I'm not that smart, by far (hehe). You're way too far up the explanatory hierarchy. A starting point are rather the laws of nature, of which Roger Penrose makes a good point that they are not enough understood to make inroads to an understanding of consciousness. At the beginning, consciousness and qualia must be based upon something mechanistic. Penrose argues that QM is incomplete (a non-computational component most likely), I would add that not only GR and QM should be unified (we need to find out where both are wrong), but the triad of Information theory (which I consider the most fundamental), GR and QM should be unified. Maybe this would leed us to conclude (proto-)consciousness is pervasively embedded at the most fundamental level of nature. I think it must be. So why wouldn't a rock be conscious? Maybe because its composition and arrangement of atoms doesn't allow it to be a facilitator to quantum information processing like neurons. Maybe neurons - in their composition and arrangement of atoms and biochemical state and interconnectedness - are especially apt acting as a facilitator harboring microtubules that store and process qubits. In any case, i haven't and can't answer your question, sorry.
>I've also given up on proving the existence of God!
I agree the non-existence of god can't be proven, and is not provable even in theory. But I've worked around it by arguing that the soul can't exist, considering the theory of evolution. At what point of the evolution exactly would god have turned us human by magically inserting a soul? And if this principal instrument of god doesn't exist, maybe the idea of god is also a bit nonsensical. Good enough for me! (And as I always joke, Thumbs up if you believe you have a soul).
>However, I don't think science (or philosophy for that matter) currently has the ability to propose an explanation for how some process p implements qualia.
Agree completely on that one.
>QM argument really does seem like the pituitary gland of the 21st century.
Eesh, not that again ... :)
>Respectfully, have you considered the possibility that your ideas just don't add up?
I actually consider this the most likely possibility, yes.
>(links welcome)
Already mentioned in my original post. Enjoy diving deep in the rabbit hole of Orch OR! If you got heaps of time, watch a few youtube videos of Penrose (and Hammeroff) explaining the concept. It's really inspiring watching the most eminent scientist currently on the planet (imsvho).
Yes. Our experience of (or as) consciousness may be biased by having a brain. Consciousness may not require thought or senses in the way that we know it. They key is in the observer, and the observer effect that makes the brain aware of the observer (giving rise to self awareness).
Consciousness cannot be proven, but it does affect the conscious being, so there are potential observable effects that might differentiate conscious existence from non-conscious existence (assuming it exists).
A rock may be conscious and the consciousness would observe being stone. Thought may not necessarily be a requirement for consciousness. It would not think that it is stone, it would not have any memories, it might not feel anything. It might be a rather dull consciousness, or perhaps it observes the forces that hold the rock together. Perhaps it experiences the forces on the rock as an 'otherworldly' sense that we cannot imagine. But it would not think about it, nor remember it, those are functions of the brain.
Or perhaps its rock shape is its memory.
Physical storage.
Why? You've presented no argument! This is just a declaration of faith!
>So why wouldn't a rock be conscious?
Indeed why not, but then again why would it be? This position is called panpsychism. It is hardly new, and hardly specific to QM. If you want to posit consciousness as a fundamental natural force, we need to be able to predict and measure it in all things, including rocks.
>Maybe because its composition and arrangement of atoms doesn't allow it to be a facilitator to quantum information processing like neurons.
Perhaps. Or perhaps a rock doesn't integrate information as much as a brain? That's what Giulio Tononi thinks [0], and at least his panpsychic theory has managed to collect some evidence (n.b. it suffers from exactly the same problem as QM with respect to mechanism).
Even if we buy the panpsychic argument (after all, why not!), you have made no argument for quantum mechanics as opposed to information-integration, or indeed anything else! None! Zero! Panpsychism does not imply quantum mechanics!
>In any case, i haven't and can't answer your question, sorry.
I appreciate the concession, but I'm afraid I must now insist upon a subsequent one. You must concede that your only reason for thinking QM is involved is because you don't see a reason why it wouldn't be. That's a bad reason.
>I actually consider this the most likely possibility, yes.
That contradicts your insistence of QM as the likely candidate for phenomenological consciousness. Either you think that assertion has merit, or you think it doesn't. Which is it?
>Already mentioned in my original post.
Yes, I was asking for things I might not already be familiar with. Am I to conclude that this theory hasn't made any progress in 15 years?
[0] https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.34...
Not good enough for free will, which needs true unknownability, like in, we don't know whether Schrödinger's cat is dead or alive, until we look.
Your theory adds zero explanatory power.
I can assure you that Philosophy of Mind is part of the curriculum. About a third of my dissertation deals with Descartes, Helmholtz, Ryle, Dennett, Searle, and others.
The general consensus among my peers is that philosophy is an essential part of scientific inquiry. Studying philosophy of mind is regarded as the only way to ensure the empirical questions we're asking even make sense, or that our discoveries are non-trivial.
It bears repeating: the cognitive neuroscientists I frequented have a deep respect and genuine interest in philosophy.
[0] Specifically: I presented evidence that attention was a causal mechanism in conscious access. We were able to take stimuli that were initially not consciously perceived, and induce a conscious percept after the stimulus had disappeared by manipulating exogenous attention.