How the brain 'generates and loses consciousness'

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The following study, from 2019, does use the terms 'could' and 'might', but I'm not exactly certain about the implications, especially for NDEs under anaesthesia.

https://neurosciencenews.com/consciousne...oss-13009/


Quote:How does our brain generate our consciousness? And why do we lose it during anaesthesia? Influential theories suggest that consciousness depends on the brain’s ability to discriminate between a specific sensory input and a large set of alternatives, akin to being able to choose one outcome among many.

A research team led by Columbia University, however, hypothesized that a person’s ability to discriminate between a set of alternatives at any moment should be rooted in micro-patterns of activity, or microstates, at the level of local neuronal ensembles – the functional building blocks of neural circuits. 

And in a first of its kind study, researchers from Columbia’s Rafael Yuste’s Laboratory used cellular resolution in vivo two-photon calcium imaging in mice to investigate changes in the local repertoire of neuronal microstates during anesthesia. The team found that anesthesia disrupts the number of neural patterns by reducing both network microstates and neuronal ensembles in the cortex, and confirmed their findings in microelectrode array recordings from two human subjects. Their results, published today in the journal, Cell Systems, indicate that the functional connectivity of the brain during mLOC breaks down across micro- and macro-anatomical scales.

“This study is important because it takes the question of the nature of consciousness to the neuronal circuit level,” said Rafael Yuste, director of the Yuste Lab and professor of Biological Sciences and Neuroscience at Columbia. “It provides an intellectual thread that could explain how alterations in the coordination of small groups of neurons, either by pathologies or anesthetics, could lead to alterations in consciousness,” added Yuste, who is also a member of Columbia’s Data Science Institute and an initiator of the BRAIN Initiative...

..."our results indicate that the loss of consciousness could arise from alterations in the local microcircuit, which would secondarily generate deficits in macroscale connectivity” added Wenzel, who at the time of study was an Associate Research Scientist in the Rafael Yuste Lab."

The study, “Reduced Repertoire of Cortical Microstates and Neuronal Ensembles in Medically Induced Loss of Consciousness,” offers a foundation for understanding how dynamics of local neuronal ensembles could contribute to the loss or emergence of conscious states. The authors noted that mechanistic studies on the role of local circuits in the loss or gain of consciousness remain challenging, though they hope their research adds to the basic science of the neural circuitry.
I feel like this should be given serious consideration. There are NDEs with signs of complex consciousness under anaesthesia, such as the Al Sullivan case. Does this study conflict that? Is this not supportive of consciousness emergence from the brain, or is there mroe to this that I'm not seeing?

Quote:Disclaimer:
As noted here there's a good reason to reject this is proof materialism/physicalism is true, given these skeptical parties that continue to doubt the physicalist/materialist faith.


Additionally, whatever is shown by parapsychology or neuroscience, here are four good reasons to reject the religion of physicalism/materialism.
(This post was last modified: 2020-07-06, 07:53 PM by OmniVersalNexus.)
Literally in the last line of the summary it says it’s about the emergence of conscious states, so like being awake. This doesn’t seem to be about phenomenal consciousness. And I don’t see how this would take away from NDEs that do occur under anaethesia, because there still shouldn’t be any such experience occurring because of it.
(This post was last modified: 2020-07-04, 08:20 PM by Silver.)
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(2020-07-04, 08:18 PM)Silver Wrote: Literally in the last line of the summary it says it’s about the emergence of conscious states, so like being awake. This doesn’t seem to be about phenomenal consciousness. And I don’t see how this would take away from NDEs that do occur under anaethesia, because there still shouldn’t be any such experience occurring because of it.
I thought conscious states were about awareness too? Not just wakefulness? 

If that's the case, since unlike you guys I'm not even very familiar with neuroscientific terms, how can I tell when a study is talking about conscious states or phenomenal consciousness? Is there any easy way? I know I'm a pest on here, and a bit of an idiot lol, but I still appreciate these responses. 

Sorry if I misunderstood the article, Silver. Thanks for the clarification.
I’m not that familiar with neuroscience either, I’ve just noticed that from reading about this stuff people will use the term consciousness for multiple things. Based on how the article talks about consciousness and why it’s lost under anesthesia, that to me says this is ultimately about waking consciousness (a particular conscious state) and the structures in the brain that allow us to be awake and what happens to them when disrupted. This doesn’t explain why it feels like anything to see the color red or to taste chocolate, thats phenomenal consciousness and what’s talked about when discussing the hard problem. Obviously conscious states are related to awareness (you’re more aware of things while awake then asleep) but there’s still an explanatory gap for why these states should feel like anything subjectively.

I’d say the best you can do is see how consciousness is talked about. In cases like with anesthesia it’s probably talking about waking consciousness, since it directly effects that. And it’s alright, I understand and think I’m similar to you in regards to this stuff. That’s kinda why I’m trying to have unnatural experiences directly, so I’ll have a more direct knowing.

Though I think other people here would be better able to explain this than me, like Sci or Nb.
(This post was last modified: 2020-07-04, 09:30 PM by Silver.)
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This is from the recent psychedelic thread, from Sci, but I figured it was relevant to this:

Yeah, it's correlation. 

The issue regarding Consciousness - by which I mean Subjective Feeling, Use of Reason, and Thoughts About Stuff - [is] not something that will be resolved with studies like this. 

That said, we will find more and more correlations. These will be more fine-grained, with specific parts of the brain (and rest of the body) correlated with specific brain states.

But the problem for materialism is specifically that you are starting with something that has no mentality - the physical world - and trying to get consciousness. It's a Something from Nothing issue.”

Edit: Additonal thing from Sci: “Regardless of metaphysical position, there has to be some minimum set of structures in the brain responsible for conscious state.”
(This post was last modified: 2020-07-05, 12:19 AM by Silver.)
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I'd look at it this way ->

I'm not a big Sam Harris fan, given his pseudo-skeptic leanings. But he is a New Atheist Horseman with a Neuroscience PhD who said Materialism is Nonsensical. His wife is publicly advocating that at the least Panpsychism should be taken seriously as a theory where consciousness is a sort of like a field across space and time.

Michael Shermer has also moved to the position that the Hard Problem of Consciousness is not solvable, so he's not anti-materialist but a Mysterian now.

The American Psychological Association published Transcendent Mind, a book filled to the brim with Psi data and anti-materialist arguments.

These are all "conservative" in regards to traditional brain=mind materialist positions - if any study suddenly came out and invalidated the above I expect all of these people and associations to return sharply into the materialist fold.

So far, they have not.
'Historically, we may regard materialism as a system of dogma set up to combat orthodox dogma...Accordingly we find that, as ancient orthodoxies disintegrate, materialism more and more gives way to scepticism.'

- Bertrand Russell


(This post was last modified: 2020-07-05, 12:33 AM by Sciborg_S_Patel.)
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