Not alive, but not dead: disembodied human brains used for drug testing • Hacker News Board

Re: Not alive, but not dead: disembodied human brains used for drug testing

#211

Post by hackingonempty » Fri, May 22, 2026, 2:03 PM UTC

rendx wrote: post #163

hackingonempty wrote: post #160

Earlier quoted context omitted.

We understand the fundamental laws of physics well enough to say there is not some mysterious soul influencing the brain. Just like we can say that the moon is not made from cheese. > Modern physics, in other words, provides evidence for what philosophers call “causal closure of the physical”: physical events have purely physical causes (Loewer 1995, Papineau 1995), at least in the regime relevant to human life. With…

> We understand the fundamental laws of physics well enough to say there is not some mysterious soul influencing the brain. Just like we can say that the moon is not made from cheese. I don't see how this relates to the "seat of consciousness" (with)in a human body, or how the biological system works together to "form it". Or where thinking or memory storage or retrieval takes place. At least that was what I was talk…

> It is a theory that we think in the brain. As far as I understand it, and please prove me wrong, there are other, valid theories? It's unscientific to discard theories purely based on belief. You seem to be arguing from a certain belief, not from science.

The evidence that the brain is where thinking happens is overwhelming, the minor influence of the rest of the body notwithstanding. There are no other theories.

Re: Not alive, but not dead: disembodied human brains used for drug testing

#212

Post by cstrahan » Fri, May 22, 2026, 6:49 PM UTC

VectorLock wrote: post #85

dhosek wrote: post #60

Earlier quoted context omitted.

When I had my ear surgery about 20 years ago, the doctor explained to me that I would be awake for part of the procedure, but the anesthesia meant that I would have no memory of it.¹ It’s a weird thing to think about whether that lack of memory would obviate the pain or discomfort of the moment. ⸻ 1. As it turned out, I was so frightened in the lead-up to the surgery that they had to do general anesthesia on me becau…

I had the same thoughts "but won't i feel it THEN?" when I was getting an upper endoscopy. The anesthesiologist said you're in such a trance, dreamlike state plus with the inability to form memories its like you're not your real "consciousness" but something different. Sort of like your brain is in "limp mode" and its not really _you._ This was both comforting and slightly terrifying in a different way.

I've had an upper endoscopy and a colonoscopy, both the same day, and both without anesthesia. If they didn't take a biopsy, it likely shouldn't have been too traumatic, consciously or subconsciously - maybe that's a bit comforting to know.

Re: Not alive, but not dead: disembodied human brains used for drug testing

#213

Post by rendx » Sat, May 23, 2026, 4:00 PM UTC

hackingonempty wrote: post #211

rendx wrote: post #163

Earlier quoted context omitted.

> We understand the fundamental laws of physics well enough to say there is not some mysterious soul influencing the brain. Just like we can say that the moon is not made from cheese. I don't see how this relates to the "seat of consciousness" (with)in a human body, or how the biological system works together to "form it". Or where thinking or memory storage or retrieval takes place. At least that was what I was talk…

> It is a theory that we think in the brain. As far as I understand it, and please prove me wrong, there are other, valid theories? It's unscientific to discard theories purely based on belief. You seem to be arguing from a certain belief, not from science. The evidence that the brain is where thinking happens is overwhelming, the minor influence of the rest of the body notwithstanding. There are no other theories.

How can you claim that "There are no other theories"? Do we operate from a different definition of "theory" perhaps?

https://en.wikipedia.org/wiki/Philosophy_of_mind

Plenty of examples of theories listed there, no? Picking a random one: "Open individualism states that individual personal identity is an illusion and all individual conscious minds are in reality the same being".

https://en.wikipedia.org/wiki/Extended_mind_thesis

"the extended mind thesis says that the mind does not exclusively reside in the brain or even the body, but extends into the physical world"

To state it explicitly, I am not saying I believe in these alternative theories. I am also not stating anything about their probabilities. I just want to be accurate in my understanding, which is that multiple theories do exist and none of them have been proven or disproven. It is not known whether you only need a brain to think, or how much other regions like the nervous system spread throughout the body play a crucial role for "thoughts" to form.

If you discard a theory just because you judge there not to be sufficient evidence, you're working from a belief, and not from scientific reason.

In this particular thread, we're not even coming from "thinking" or "mind", but from sentience -- the stated idea that the "brain can feel pain", as brain alone (!). Depending on which physical regions and matter you include in "brain", it doesn't even have any structures that according to the current scientific consensus provide or relay perceptive data. Unless you believe in one of the many theories that place the mind outside of the physical structures of the brain.