The brain receives almost no input, maybe none at all.

[axiom]

I thought this was an interesting scientific tidbit insofar as it relates to mysticism... clues within a dream.

It is now the current mainstream scientific view that the brain receives almost NO inputs relative to the information that it self-generates. 

The brain's predictive modelling processes work from the top down. This means that in any given situation, it predicts what inputs it is most likely to receive from the environment and this self-concocted "best guess" is what you experience as the world. 

In effect, the only time the brain uses environmental data is when something about its model triggers an error message, i.e. when its model appears to be flawed.  Error messages are known to form a tiny, tiny fraction of the brain's model-building processes.

So, when mystics say that the world is imaginary, mainstream science is actually today more than 99.9% in agreement. 

[Yarco]

To a degree this makes sense. If somebody tells you that a pool is freezing cold, you're going to amp yourself up. Even if the water is actually bath-warm you'll probably start hyperventilating and tensing your muscles pre-emptively. It might even feel cold for a split second until your brain triggers that error message.

This self-generated input also allows you to act on autopilot for most tasks that you do repetitively. You've probably experienced doing something when you're deep in thought, and then having no memory of actually doing it.

It takes about 100 ms for data from your eyes to reach your brain and being able to actually act on it. By predicting our world we can fill in the gaps and make it appear free of delay most of the time.

The thing is that I suspect we are triggering that error message and running into discrepancies a lot in life. More than you would expect. You're walking and bump into something, error message. You look out the window expecting to see nothing and a bird flies past, error message. Walking down the aisle and there's a red sale sticker next to your favorite pasta sauce, error message.

So in an average day where you eat the same cereal, drive the same route to work, do the same task... I would imagine your brain can ignore 80% of inputs and only do occasional audits to make sure things are aligning. But if you're at day 1 of a brand new job or starting a new grade in school, or travelling in a strange country for the first time, your brain is probably having to take in closer to 100% of inputs because you can't predict anything. You can tell this is going on because you'll feel way more tired at the end of the day when you've actually had to use your brain for once.

[Carl-Richard]

Want to blow your mind even more? Psychedelics decrease net brain activity.

[Gesundheit2]

15 hours ago, axiom said:

This means that in any given situation, it predicts what inputs it is most likely to receive from the environment and this self-concocted "best guess" is what you experience as the world. 

Environment is input.

[axiom]

4 hours ago, Carl-Richard said:

Want to blow your mind even more? Psychedelics decrease net brain activity.

That is because they collapse the default mode network (subject and object, the sense of ‘I’).  The monkey mind settles down significantly, sometimes to zero depending on dosage / substance.

Activity in other brain regions related to focus can increase though. 

[axiom]

2 hours ago, Gesundheit2 said:

Environment is input.

Yes, but the point is that the brain does not check the environment at all unless its model throws up an error. Your phenomenological world is almost entirely concocted by inputs that began their life within the brain itself. Like a self-feedback mechanism. Snake eating it’s own tail, ourobouros…

[Gesundheit2]

@axiom https://en.wikipedia.org/wiki/Predictive_coding

Quote

In neuroscience, predictive coding (also known as predictive processing) is a theory of brain function in which the brain is constantly generating and updating a mental model of the environment. The model is used to generate predictions of sensory input that are compared to actual sensory input. This comparison results in prediction errors that are then used to update and revise the mental model.

Where does the theory say that the brain receives no inputs from the environment?

[Matt23]

On 6/7/2022 at 2:35 AM, Carl-Richard said:

Want to blow your mind even more? Psychedelics decrease net brain activity.

Haha lolz.

So fried eggs truly are your brain on drugs?

 

1 hour ago, Gesundheit2 said:

Where does the theory say that the brain receives no inputs from the environment?

Also, @axiom, ya, where did you find this info?  sources?

[Carl-Richard]

On 7.6.2022 at 3:54 PM, axiom said:

Activity in other brain regions related to focus can increase though. 

Based on what I've heard, it's only a relative increase compared to other brain regions, but the same area still has lower activity compared to the sober state.

[axiom]

@Gesundheit2 @Matt23

I didn't say it receives no input. I said it only "receives" input when its modelling throws up an error message. As per the thread title, it's definitely fun to consider that it may receive no input at all, but that's not really what I'm talking about here.

Quote

In neuroscience, predictive coding (also known as predictive processing) is a theory of brain function in which the brain is constantly generating and updating a mental model of the environment.

This is correct. To get more technical about it, I could say that the cortical columns of the cerebral cortex only update their modelling (your phenomenal world) when the lowest columnal region/s check their patterns against environmental inputs and find errors. The word "predictive" in the above quote refers to the way the brain uses its own data to generate its own patterns by making "best guesses" or "predictions" about the external environment. 

In other words, whatever you experience - generally speaking - is what your brain merely predicts to be there. If no errors are thrown up, then it won't update its modelling. Errors aren't thrown up when predictions are veridically incorrect, but rather when the model functions incorrectly for some reason, for example when you try to pick up a glass and it ends up being closer than you thought it was. The cognitive psychologist Donald Hoffman notes that this process is optimised for survival and not truth per se.

Quote

The model is used to generate predictions of sensory input that are compared to actual sensory input. This comparison results in prediction errors that are then used to update and revise the mental model.

Yes. In effect the lower cortical columnal regions are siloed from higher regions and their activity does not feed into consciousness unless an error is detected and the model updated.

Quote

Also, @axiom, ya, where did you find this info?  sources?

It is known as Predictive Processing. The implications are very interesting if you compare this to the now-considered-erroneous idea that the brain is constantly constructing its reality from external inputs. Here is a relatively accessible paper about it from 2015 (it has since become the mainstream view): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387510/

Psychedelics do something very interesting. On DMT for example, brain scans have shown that error messages are massively increased and force the cortical columns to significantly overhaul their predictive modelling. In other words, the brain pulls in WAAAY more data from the apparent "real external world" on DMT than it does under normal conditions. This may explain the sense of massively increased consciousness or even God-realisation. You're literally experiencing much more of what is there.

When operating under normal conditions (i.e. serotonin binding normally to 5HT2A) the brain effectively filters out the vast majority of everything (probably 99%+)... pretty mindblowing when you think about it.

Edited June 10, 2022 by axiom

[Gesundheit2]

@axiom I think you're misinterpreting the model with an idealistic bias. The model doesn't seem to necessarily suggest anything in regards to where the world actually exists (objective/materialism vs. subjective/idealism). It only seems to highlight the fact that the brain seems to function in a way that updates its current information only when the environment changes and "throws an error", as opposed to another hypothetical model that might suggest that the brain is always updating models regardless of prior knowledge that is stored in memory.

The predictive coding model assumes memory that the brain uses to compare with perceived environment. The misinterpretation you seem to be presenting here assumes that the brain's memory is somehow the reality that we perceive, which does not seem to represent at all what the model is saying.

[axiom]

28 minutes ago, Gesundheit2 said:

@axiom I think you're misinterpreting the model with an idealistic bias.

@Gesundheit2 I like Idealism, but I'm not referring to it here nor using any of its arguments. This model explicitly requires the existence of an "external world".

Quote

The model ... only seems to highlight the fact that the brain seems to function in a way that updates its current information only when the environment changes and "throws an error", as opposed to another hypothetical model that might suggest that the brain is always updating models regardless of prior knowledge that is stored in memory.

Yes, I agree with this. 

Quote

The predictive coding model assumes memory that the brain uses to compare with perceived environment. The misinterpretation you seem to be presenting here assumes that the brain's memory is somehow the reality that we perceive, which does not seem to represent at all what the model is saying.

This is where we differ. I don't think it's a misinterpretation. I think that this is literally what is being implied by the model. It suggests that the (vast) majority of information held in the brain - as your phenomenal experience - may merely be based on patterns and memories.

I appreciate it's probably quite a leap to suggest that this explains in some sense the mechanism of DMT... but I do think it's very curious that the error messages on DMT are massively increased, seemingly pulling in significantly more input than usual from the external world for pattern remodelling. 

Edited June 10, 2022 by axiom

[Gesundheit2]

15 minutes ago, axiom said:

I appreciate it's probably quite a leap to suggest that this explains in some sense the mechanism of DMT... but I do think it's very curious that the error messages on DMT are massively increased, seemingly pulling in significantly more input than usual from the external world for pattern remodelling. 

Well, this probably goes back to our (rather vague/primitive) understanding of the brain and how it functions. So the axioms of neuroscience. I'm not very well-versed in that area, so I can't probably say anything except that the map is not the territory. Though, I think from a purely scientific/practical perspective, that would probably be an irrelevant addition lol.

[axiom]

2 minutes ago, Gesundheit2 said:

Well, this probably goes back to our (rather vague/primitive) understanding of the brain and how it functions. So the axioms of neuroscience. I'm not very well-versed in that area, so I can't probably say anything except that the map is not the territory. Though, I think from a purely scientific/practical perspective, that would probably be an irrelevant addition lol.

Yes... it's quite speculative. As a fan of intuition though, I reckon there's something to it. 

If its true that the DMT realm - a crystalline, hyperdimensional, hyper-intelligent alien world teaming with curious and playful alien life - is in any sense real and is simply veiled from "regular" consciousness by the activity of serotonin... as certainly seems to be case, then the implications are fairly immense.

[Gesundheit2]

@axiom I wouldn't know until I try. But from your experience, what possible practical implications would you say DMT might have? In particular, I'm interested if you think it might be possible to derive useful psychological information about the mind of each individual that can be utilized to achieve certain goals like personal growth or healing.

[axiom]

@Gesundheit2 My hunch is that the potential applications of DMT will extend far further than today's clinical research into potential depression treatments. That's one very viable avenue of discovery of course, but I think the real thing of substance here is going to be more along the lines of space exploration, time travel, etc.

Edited June 10, 2022 by axiom

[Oeaohoo]

On 07/06/2022 at 3:00 PM, axiom said:

Your phenomenological world is almost entirely concocted by inputs that began their life within the brain itself. Like a self-feedback mechanism. Snake eating it’s own tail, ourobouros…

Careful! That’s not quite what this shows. The original input comes through the senses from the external world; this input is then formalised by the brain into a predictive model; then future input is only necessary to adjust this internal model.

There is some truth in what you say, though, in the sense that the brain is already hard-wired to make these predictive models. Reality is an Ouroboros but by definition the brain is only a part of that snake!

Edited June 10, 2022 by Oeaohoo

[axiom]

3 hours ago, Oeaohoo said:

The original input comes through the senses from the external world; this input is then formalised by the brain into a predictive model; then future input is only necessary to adjust this internal model.

Ah, but the brain has also been conditioned by millennia of adaptive evolutionary biology. Who knows to what extent the "original" (pre natal... post natal...?) input can be said to be veridical. 

[Oeaohoo]

1 hour ago, axiom said:

Ah, but the brain has also been conditioned by millennia of adaptive evolutionary biology. Who knows to what extent the "original" (pre natal... post natal...?) input can be said to be veridical. 

Ah, but all of that adaptive evolutionary biology involved sensory experience of the world external to the brain! We could go go back and forth like that forever because, like you said, it’s a snake biting it’s own tail.

[Gesundheit2]