New Bernardo Kastrup Paper: What Neuroimaging of the Psychedelic State Tells Us about the Mind-Body

#21
For example, you refer to the link between richness of experience and a broader informational space (and as someone who is partial to and sees promise in integrated information theory I agree). Now, it's possible that I'm not quite getting what you mean here but don't the elements I lay out above demonstrate exactly that? Information exchange is all about connectivity isn't it? And what the study seems to point to is that increased connectivity in the visual processing centres of the brain lead to richer, more vivid experience while decoupling of other information pathways results in a decreased sense of self, etc.

Further the power decreases were not spread out evenly and they map out relations there as well.

And don't we have to be pretty careful here to conclude that lower power throughout the brain necessarily indicates less power to specific processes. I don't know the answer to this, but the brain does a lot more than produce consciousness - what effects do these drugs possibly have on those other activity - in other words, is the power drop due to other processes going offline or working less hard? But alternatively, could these studies suggest that your premise is just incorrect? That richness of experience does is not a factor increased power but just a factor of the particular pattern of activity.

So to bring it home. I don't understand why you went out of your way to highlight the issues regarding cerebral blood flow, and ignore all the other findings, paticularly the ones related to how the informational relationships changed under LSD?

(and please note, when I say these questions are not the rhetorical I mean it. I'm not asserting you are wrong, it could easily be my understanding which is wrong, which is why I'm asking. Also I recognize that my partiality to IIT could be influencing this exchange in that while in that my understanding of how the brain generates human consciousness is not strict physicalism by some definitions and your argument may not be addressed at my understanding. I appreciate the dialogue!)
I guess you didn't understand my argument. I can only point back to my paper, where it is explained. Last try: my argument is entirely agnostic of the pattern of brain activity. Connectivity is a pattern.
 
#22
I've already referenced a study that shows that power drop is not a good indicator of activity.
Then you should take it up with the authors of the psychedelic neuroimaging studies and argue against their conclusions. Their observations and conclusions (not necessarily their _interpretation_ of the results) are my starting point.
 
#23
I guess you didn't understand my argument. I can only point back to my paper, where it is explained. Last try: my argument is entirely agnostic of the pattern of brain activity. Connectivity is a pattern.
It is certainly possible that I didn't, and I will spend some more time with it!

I do understand that your argument is agnostic of the pattern of activity. I guess my question boils down to: should it be?

Also, could you (or some of our more scientifically literate members) explain how we can determine from the results of this study, that the power reduction was related to the specific brain processes we are concerned about? Are the readings sufficiently sensitive enough to let us conclude that the particular processes that led to the richer experiences used less power. Would it let us see, for example that the increased relations in the visual context used more power but due to a decrease in other activity in the area, the overall energy readings are a net loss?

Would that affect your argument?

Even if the increased CBF readings in that areas te the result of variable confounding, would it be indicative that something was likely occurring in that area that used more, not less, power? (I acknowledge that the 2012 study didn't show that, but it's still something to consider).

And would a reduction in power be consistent with the reduced sense of self due to network disintegration?
 
#24
Just wanted to say Bernardo, I hope you don't mind my pusihing into this so much. I've been interested in your arguments about psychedellics ever since you first brought it up a few years ago and want to take advantage of this opportunity to discuss it with you. If it helps, I've bought and read two of your books! :).

Incidentally, I really enjoy reading your books - the way you lay things out meshes well with the way I process these questions. I found myself in a nice internal dialogue, i would read something, think of an issue, then see you raise the issue yourself. Although I didn't always agree with your response I found reading your books to basically be like us having a conversation - it made them very enjoyable and engaging reads! I'm not trying to flatter you, I mean it. I read a lot of this kind of stuff but it is rare that I experience that particular dynamic, and to that extent. So thank you for that!
 
#25
The whole paper is based on this premise. However, we now understand that many neurons in the brain are involved in inhibiting our experience. If these regulatory neurons are functioning with reduced metabolic activity the experience would be "richer".
More activity at a physical level corresponds to higher levels of felt experiences is central to the thesis of the paper. Do you have examples or references that support your counter-claim? My limited understanding is that regulatory neurons have as a primary function --- focal attention. They help select the circuit pathway that needs attention. The selection (informational property) is not a volume dial, but a tuning mechanism. Selecting which signals to suppress enables the gestalt of meaning to emerge. More noise is not a more vivid experience, but is one that is less clearly focused.
 
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#26
Here's another consideration: I think it is fairly we'll established that we process much more information than we consciously experience. So an increase in information awareness does not necessarily depend on an increase of information entering the brain and consequently would not necessarily require more power

That is we take in more information than what falls in our information awareness. If the shift in brain connections caused by psychedelics results in more information reaching reaching our conscious awareness (more and perhaps different bits of information that don't usually come to our woken awareness) then would it be surprising that our phenomelogical experience would change even without able increase of power).

You touch on this Bernardo, but your explanation is that it would entail specific trips are going on all the time. I'm not sure how you come to that conclusion. We're talking about information pathways becoming integrated where they previously weren't. Other pathways becoming disintegrated when they previously were. In short, we've got significantly different information exchanges going on. Why assume that these would be processed in the same was as they do in normal paths? Why assume that the information that gets added represents anything like coherent packaged trips? Rather couldn't the particular experience come out of what information happens to get integrated into the mix? the brain cobbles it together to produce something like a coherent experience.

I'll have to look closer but I think the LSD paper authors touch on this.
 
#27
Then you should take it up with the authors of the psychedelic neuroimaging studies and argue against their conclusions. Their observations and conclusions (not necessarily their _interpretation_ of the results) are my starting point.
I don't expect Carhart-Harris et al to explain exactly what EEG/MEG is measuring, or it's limitations, every time they write a paper on psychedelics. Where you've made a mistake is in equating electric and magnetic field power drops, observed by the authors using EEG/MEG, with a literal reduction in neural activity. I'm afraid such electric and magnetic field power drops don't necessarily mean a reduction in neural activity, for example, we routinely see such reductions in E/M power during event related desynchronizations (ERD's) where summed E/M fields from currents fully or partially cancel out.

In any case, as a good relevant example, I've already linked to Borjigin's highly sensitive invasive EEG (iEEG) dying study, which measured electrical activity during an energy compromised state of reduced power. That study shows *increased* synchronisation across large parts of the brain that would not be measurable by MEG used in the psychedelic study you refer to.
 
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#28
You seem to have failed to read the paper with enough attention. I start the paper precisely by addressing this point.
This is hand waving. NCCs are the neural correlates of consciousness, whatever they may look like. My argument is generic enough that I don't need to know exactly what neural dynamics are involved in the NCCs.
Surely the point is that you DO need to know exactly what they look like (in terms of the data provided by the machines we are using to measure them) if you are to distinguish them from the inhibitory neuronal activity.

I'm sure I must be missing something obvious because you have identified an issue (a drop in inhibitory activity could make the experience richer) but it is not at all clear to me how you have resolved this. You invoke NCCs (which appear nowhere in either paper) and insist they are separate from the inhibitory "circuits". With the measurements we have, the data available, how do you do this? I'm confused on this particularly as the authors of the 2012 paper seem to think their data supports a "reducing valve" model for some brain activity.
 
#29
Guys, I think you need to read this part very carefully. Seems like maybe this is where the confusion is taking place?

Not all brain activity consists of NCCs: under physicalism, there are also unconscious
neural processes. Reductions in these unconscious processes don’t necessarily imply
reductions in experience, for they aren’t NCCs. In fact, if these unconscious processes are
inhibitory in nature, their reduction could even cause an increase in NCCs and, therefore,
experience. As such, nothing precludes an increase in NCCs from being accompanied by a
comparatively greater decrease in unconscious processes, leading to an overall decrease in
brain activity. Clearly then, physicalism does not necessarily imply that more experience
should always correlate with more total brain activity
.

But here is the critical point: under physicalism, an increase in the richness of
experience does need to be accompanied by an increase in the metabolism associated
with the NCCs, for experiences are supposedly constituted by the NCCs
.
 
#30
Guys, I think you need to read this part very carefully. Seems like maybe this is where the confusion is taking place?
I think I get that. But how is Bernardo defining neural activity specifically correlating with consciousness? How is he separating out that activity (in the NCCs) from other activity (inhibitory)?

Why do the authors of the 2012 study consider that their data might support some "reducing valve" function of the brain?
 
#32
My questions focused directly on that point as well and it's worth a discussion, can you elaborate as to your view on this?
I think I get that. But how is Bernardo defining neural activity specifically correlating with consciousness? How is he separating out that activity (in the NCCs) from other activity (inhibitory)?

Why do the authors of the 2012 study consider that their data might support some "reducing valve" function of the brain?
Well, I don't want to put words in Bernardo's mouth, but it seems to me he answered your question malf, in that he said "under physicalism, an increase in the richness of experience does need to be accompanied by an increase in the metabolism associated with the NCCs, for experiences are supposedly constituted by the NCCs." It's not his "definition", but rather he's saying this is a basic assumption of physicalism and using it for his taking off point there. If you're one that normally holds to that view of physicalism, but you detect reduced NCC's during periods of intense conscious experience regardless of total brain activity (again, please see 1st paragraph I quoted above!), that would be inconsistent, so you might be drawn to conclude a "reducing valve" function for the brain instead.

I'm not really familiar with fMRI signatures, but as to your other question, I think the following is the gist of what's being said. You just need to identify/detect metabolism taking place to identify/detect NCCs taking place. Would inhibitory processes be characterized by a lack of metabolism? Two different signatures? If so, perhaps an X-ray would be a good analogy, where you are detecting regions of greater density (bones) to less density (flesh), while not caring about exactly which bones you find, but rather caring about the number of bones. Because, it would be really weird to see lots and lots of missing bones and yet find out the guy is an Olympic weight lifter.

Anyhow, I'll shut up from there and let Bernardo take over (hope I didn't twist his views!) That was pretty much my take on those parts. Not saying it is correct, because .... to be honest, my recent views are that I'm not really sure what to think of all these brain imaging scans lately. Kinda want to wait and see how the recent fMRI snafus pan out.
 
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Sciborg_S_Patel

#33
Anyhow, I'll shut up from there and let Bernardo take over (hope I didn't twist his views!) That was pretty much my take on those parts. Not saying it is correct, because .... to be honest, my recent views are that I'm not really sure what to think of all these brain imaging scans lately. Kinda want to wait and see how the recent fMRI snafus pan out.
I think what's interesting is when you parallel this argument Bernardo is making with the long standing but admittedly anecdotal reports of increased Psi functioning via psychedelics (note this isn't encouragement to use, as I think adverse effects need to be sorted out via more research).

Then you look at the transmitter-filter type models and look at the way Psi is supposed to be a "jiggering" of the filter.

All to say nothing definitive, but a good direction parapsychology can utilize as the bans* on psychedelic research go down in the next decade.

*Thanks for nothing Leary.
 
#34
More activity at a physical level corresponds to higher levels of felt experiences is central to the thesis of the paper. Do you have examples or references that support your counter-claim? My limited understanding is that regulatory neurons have as a primary function --- focal attention. They help select the circuit pathway that needs attention. The selection (informational property) is not a volume dial, but a tuning mechanism. Selecting which signals to suppress enables the gestalt of meaning to emerge. More noise is not a more vivid experience, but is one that is less clearly focused.
There's a lot still to understand about inhibitory systems function and what they achieve. I don't think increased "focus" and dialing down the overall experience are necessarily mutually exclusive though.

This paper is interesting, and also references a lot of other papers in the (currently, relatively small) field.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4254329/
 
#35
I've had a bit more time to process that 2012 paper. To me, Bernardo's error is to assume that reduced CBF to those parts of the brain found in the study represent some sort of neural correlates of consciousness, whereas all they really represent are neural correlates of psilocybin use.

Careful reading of this passage is key IMO:


... It is noteworthy that the regions which showed the most consistent deactivations after psilocybin (e.g., the PCC and mPFC) are also those that show disproportionately high activity under normal conditions (26). For example, metabolism in the PCC is ∼20% higher than most other brain regions (27), yet psilocybin decreased its blood flow by up to 20% in some subjects. There is some mystery about the function of the PCC; its large size, buffered location, and rich vasculature means that it is well protected from damage. The high metabolic activity of the PCC and the default-mode network (DMN) with which is it associated (26) has led some to speculate about its functional importance, positing a role in consciousness (28) and high-level constructs, such as the self (29) or “ego” (30, 31). Indeed, the DMN is known to be activated during self-referencing (28) and other high-level functions linked to the self-construct (27). Moreover, DMN regions are also known to host the highest number of cortico-cortical connections in the brain, making them important “connector hubs” (32). These hubs may be critical for efficient information transfer in the brain by allowing communication between different regions via the fewest number of connections (33). However, such an integrative function would confer a significant responsibility on these regions, which may explain why their deactivation has such a profound effect on consciousness, as shown here.
 
#36
Here's where I'm having an issue. Bernardo writes:

Therefore, a relative increase in local metabolism is necessary to create the broader information space in the brain that supposedly constitutesthe broader information space in awareness entailed by richer experiences. This is an inescapable implication of physicalism.​

I've summarized the findings on the increased information relationships above. Am I wrong that it is those relationships that can be interpreted as forming the broader information state required for richer experiences that Bernardo refers to (and that are also required by integrated information theory?).

If so, wouldn't we have to accept that whatever the metabolic state of the brain at that time, it was sufficient to power that broader information state, thus resulting in the phenomenological experiences described.
 
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Sciborg_S_Patel

#37
Maybe this would be easier to discuss if we looked at the processing power necessary to generate more vivid scenes in computer games?

Like compare Super Mario to the latest graphical wonders of today...are people trying to say you can get drastically improved graphics/sounds without an increase in power consumption? (I realize the power consumption doesn't necessarily have to rise by much, but there should always be an increase IIRC?)
 
#38
Maybe this would be easier to discuss if we looked at the processing power necessary to generate more vivid scenes in computer games?

Like compare Super Mario to the latest graphical wonders of today...are people trying to say you can get drastically improved graphics/sounds without an increase in power consumption? (I realize the power consumption doesn't necessarily have to rise by much, but there should always be an increase IIRC?)
Do computer consoles have plastic inhibitory feedback loops?
There is nothing sensory in your analogy.
 
#39
Maybe this would be easier to discuss if we looked at the processing power necessary to generate more vivid scenes in computer games?

Like compare Super Mario to the latest graphical wonders of today...are people trying to say you can get drastically improved graphics/sounds without an increase in power consumption? (I realize the power consumption doesn't necessarily have to rise by much, but there should always be an increase IIRC?)
I don't know but there you are adding pixels that weren't there before. In this case we have information streams that were there before but have shifted course to integrate differently, if I understand it correctly. We're talking about a reallocation of information that was already being processed, not an increase of information coming in from outside being processed in the brain. Am I correct?

But even if it is the case, the question must be posed whether the technology used is subtle enough to differentiate to that extent? If enough surrounding metabollic function was down, would it be subtle enough to detect an increase there. Maybe this is obvious to people familiar with these machines, but I don't know.

My question is: if what LSD does is shift some information pathways to be integrated that were not previously, and shift some other pathways to stop being integrated when they previously were, is that going to necessarily involve more and less power respectively? Or at least, more or less that will show up on these scans.

Note, the power reduction, while deeper in a few areas than others, were widespread in the brain. Suggesting, if I understand correctly, that they involve way more than just our cognitive faculties (whether conscious or unconcious). I don't think the paper goes too much into exploring what else may have gone offline. Or am I misunderstanding this? What other bodily functions were affected other than mental faculties?

And again, it may simply be incorrect that increased richness of experience due to reallocation of resources would require the same kind of metabolic shift that might be required when looking up at a dark night sky and then turning on some Mozart.
 
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Sciborg_S_Patel

#40
Do computer consoles have plastic inhibitory feedback loops?
There is nothing sensory in your analogy.
There's nothing sensory in physicalism either, not at the final level of reduction?

If you're talking about different patterns being responsible for higher intensity experiences you're talking about something akin Patternism. But if we're assuming non-absurdist physicalism it seems to me one has to assume a positive correlation between the intensity/vividness of an experience and the "processing power" utilized to produce that experience?

I don't know but there you are adding pixels that weren't there before. In this case we have information streams that were there before but have shifted course to integrate differently, if I understand it correctly. We're talking about a reallocation of information that was already being processed, not an increase of information coming in from outside being processed in the brain. Am I correct?
What does it mean for information to be integrated? (What does "information" mean in this context?)

Additionally, is IIT even a physcialist theory? - I ask because it seems at times even the authors aren't clear on this.
 
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