[a-r-t]

From the article: "The researchers also applied their technique to three-millimeter cubes of brain tissue from a 9-month-old girl with epilepsy. The tissue maintained its pre-freezing structure and remained active in a laboratory culture for at least two weeks after being thawed."

[Waterluvian]

> and remained active in a laboratory culture for at least two weeks after being thawed

I’m sure I don’t fully understand the details but this kind of thing both excites and horrifies me when I ponder how much brain might be necessary to sustain the experience of consciousness.

[lisper]

My personal opinion is that it's not just about brain quantity. I think being embedded in an environment is necessary for consciousness. My argument is that there is no such thing as unqualified consciousness -- you have to be conscious of something. You're not born aware of yourself, you spend the first few years of your life figuring out that you are embedded in this thing called a human body that, with considerable practice, you can exercise more-or-less direct control over. After more years you figure out that your body is further embedded in a world full of other things that you have only indirect (at best) control over, or no control at all. Only after all that can you draw a line between you and not-you and become aware of "your" existence.

[strogonoff]

I would not equate self-awareness with the feeling of being enclosed in some distinct thing called a human body that you can exercise control over. With the latter you are not just self-aware, you are also deconstructing experience into parts according to a particular dualistic approach (“that is my body, this is me”). Such deconstruction may not be required, and whether it is the only or even the best approach to qualifying own being is dubious (some might say you and your body are the same and implicitly treating “you” as “contained in your brain” is a fallacy—from the perspective of natural sciences a good illustration is probably how gut flora changes, non-brain organ transplantation, and such correlate with shifts in your personality).

[lisper]

> how gut flora changes, non-brain organ transplantation, and such correlate with shifts in your personality

Well, yeah, but so what? You can have shifts in your personality and still be you. You can be grumpy one day and happy another and still be you. And those changes can be cause by environmental changes far less radical than organ transplants.

The one thing you cannot swap out and still remain you is your brain.

[strogonoff]

Organ transplantation personality changes are not about happy one day and sad another day.

> The one thing you cannot swap out and still remain you is your brain.

Wrong. You can also not swap out your body and remain yourself.

> You can have shifts in your personality and still be you.

When do you stop being yourself? What makes you yourself? Think about it—it is not an easy question to answer.

[lisper]

> You can also not swap out your body and remain yourself.

Why not? Even taking technological limitations into account, there is almost no part of your body that can't be swapped out even today. People have artificial limbs, artificial hearts, artificial ears. They get lung transplants, kidney transplants, face transplants. Give the technology a few more centuries and I don't see any reason why a complete body swap-out should not be possible.

> it is not an easy question to answer

Indeed. But most people would agree that you can get an organ transplant or an artificial limb or a hearing aid or wear glasses -- or any combination of the above -- and still be you. Not so for a brain transplant.

[Byamarro]

Yet you can remain conscious in deprivation chamber. I feel that this approach is too high level to technical details how brain may really work.

[lucubratory]

But sensory deprivation chambers are both known to make people unconscious, don't completely remove all sensation, and still induce hallucinations reliably. The conscious entity has to be conscious of something, and if there's nothing it will create something to be conscious of.

[lisper]

Also, going into a deprivation chamber as an adult is very different from being raised in one.

[thaumasiotes]

> You're not born aware of yourself, you spend the first few years of your life figuring out that you are embedded in this thing called a human body

This is Piaget-level garbage.

[jaybrendansmith]

Please, educate us. Why is it garbage? To me and perhaps others, this makes intuitive sense. Why shouldn't it take several years for an intelligence to build self-knowledge before it can develop what we call consciousness? Why shouldn't consciousness be emergent, as an intelligence slowly understands that it is limited to a physical form?

[thfuran]

Why shouldn't it be baked into the neural structure that has evolved over the past half billion years? Why should it require years after birth to manifest?

[thaumasiotes]

You hope that people will realize what they're doing before they argue that normal children aren't conscious, but no.

[osigurdson]

The brain is not constant during this process however. It is developing at the same time.

[lisper]

Yes, well, that is one of the many reasons I hedged with "My personal opinion is..."

[osigurdson]

Is your opinion immutable?

[velcrovan]

Even the actual entire brain you have right now can't sustain the experience of consciousness during sleep, or while under the influence of sedatives, or during times of sudden trauma.

[hooverd]

Have we even figured out how anesthesia actually works yet?

[dmbche]

look into the Portia spider - fun rabbit hole!

[lucubratory]

Have you read "Children of Time" by Adrian Tchaikovsky? Because if not, you absolutely should.

[dmbche]

I know! It's on my list.

I heard of it from Peter Watts, in Echopraxia (Blindsight is wonderful as well!)

[lallysingh]

Meh. If we want immorality we'll probably end up converting a brain scan to an LLM.

Medically this could be great for preventing brain damage.

[zamalek]

ANNs can't represent everything involved with a functioning brain, never mind a highly specific ANN architecture. Any consciousness or similar would need to arise via an independent mechanism.

[ben_w]

> Any consciousness or similar would need to arise via an independent mechanism.

Probably, but even then only due to there being a lot mechanisms and we don't know which of them is related to the subjective experience of existing that is the meaning of conscious I assume you're using here (there's something like 40 definitions of "consciousness").

But because we don't really know where the capacity for an inner experience even is, it's not impossible that even an LLM, which totally isn't designed with the goal of having it, might nevertheless have it.

(I really hope they don't, I statistically suspect they don't, I just can't rule it out).

[DennisP]

It's not impossible that rocks have consciousness. Some modern philosophers advocating pantheism think they just might.

Meanwhile, according to Sabine Hossenfelder, a recent paper shows evidence that Penrose was right about quantum effects happening in the brain:

https://www.youtube.com/watch?v=R6G1D2UQ3gg

[Nevermark]

> Some modern philosophers advocating pantheism think they just might.

This is a terribly low bar. The map of “ Some modern philosophers” “think [something] just might” [something] is an incoherent patchwork.

I think that theorizing about things without hard evidence has value. What-if’s teach us a lot, by raising important questions, and keep our ideas flexible, preparing us for the next crazy insight that nature reveals.

But that isn’t the same as attributing any reliability to the as yet unproven enthusiasms of philosophers.

There is a clear case for a survival benefit for creatures whose awareness and control extends into their own thinking. Thus a reason consciousness would be one of many strategies evolution may produce.

What natural phenomena is explained by a conscious rock hypothesis? What would cause a rock to organize in such a way? Where is this information about itself encoded and experienced in a rock? It’s not a coherent conjecture.

[zamalek]

> t's not impossible that even an LLM, which totally isn't designed with the goal of having it, might nevertheless have it.

I was referring to the idea that a brain scan of a human could be copied into an LLM.

[ben_w]

Oh, in that case I agree. My understanding is LLMs (or at least GPT-architectures) aren't Turing machines, so they can't simulate arbitrary other systems even if you made them very big, and because of this my guess is that it would be extraordinarily unlikely for them to just happen to have the right shape and power for simulating a full human brain.

[wonderwonder]

I think OP means how do we know that the brain tissue that is being used in the experiment is not conscious.

Here is a man that lived a normal life with 90% of his brain damaged, a large portion of that just completely missing.

https://www.sciencealert.com/a-man-who-lives-without-90-of-h...

[ben_w]

Sneaky paragraph at the bottom:

> Update 3 Jan 2017: This man has a specific type of hydrocephalus known as chronic non-communicating hydrocephalus, which is where fluid slowly builds up in the brain. Rather than 90 percent of this man's brain being missing, it's more likely that it's simply been compressed into the thin layer you can see in the images above. We've corrected the story to reflect this.

[wonderwonder]

I did not see that actually, thank you.

The fact our brain can be compressed to that level is pretty crazy too, although not as impressive as the original missing 90% :)

[ben_w]

You're welcome :)

I very nearly missed it on that page, despite already being aware of the detail from other sources.

[scarmig]

Network pruning.

In ANNs, pruning 90% of the weights without substantial loss isn't unheard of. I guess this may be analogous: continuous pruning and fine tuning over a lifetime. Though, is removing 90% of the brain more analogous to 90% of weights, or 90% of the rank?

[Waterluvian]

At this point it feels like we’d required the resources of an entire planet to run a single full-fidelity virtual brain. Which leads to interesting science fiction premises.

[hateful]

Or one entire actual brain - if it can be done once by natural selection, it can be done more efficiently again by a designer.

Time exists because the universe doesn't do calculations - the only way to see the outcome is to do the thing. See: The Three Body Problem

[hateful]

See: https://news.ycombinator.com/item?id=40508705

[ben_w]

Last I heard (I am not a brain scientist) we don't really know what fidelity we would need.

https://en.wikipedia.org/wiki/Mind_uploading#/media/File:Who...

[zaptrem]

Likely relevant to source of the living brain tissue:

“Brain biopsies on 'vulnerable' patients at Mount Sinai set off alarm bells at FDA, documents show” https://www.cea.fr/english/Pages/News/world-premiere-living-...

[Atotalnoob]

A millimeter cube seems large when it comes to a 9 month… Let alone 3…

This seems weird that they got this much LIVING brain tissue…

[victorbjorklund]

Resective surgery is the most common epilepsy surgery. It involves the removal of a small portion of the brain. The surgeon cuts out brain tissue from the area of the brain where seizures occur. This is usually the site of a tumor, brain injury or malformation

https://www.mayoclinic.org/tests-procedures/epilepsy-surgery...