Not alive, but not dead: disembodied human brains used for drug testing (opens in new tab)

PTSD can happen especially when something goes wrong with the anesthesia. Happened to a man named Sherman Sizemore many years ago: https://www.nbcnews.com/health/health-news/family-sues-after...

Dramatized retelling of the story at 21m04s: https://m.youtube.com/watch?v=ny_s07D-LT8&t=1264s

I have vivid dreams and smells from a surgery where the visions and feeling of them poking me are incredibly intense. The question is whether it’s a memory or a manifestation of fear. I rarely dream (every few years), but this vivid dream comes through on occasion.

Obviously it would be worse if you remembered it, but the trauma is still there even if you don't. Ask Bill Cosby's victims.

A colleague warned me of the same when I was having my wisdom teeth removed. As a result, while I was being put under, I was very focused on the effects of the anaesthetic. I feel about as confident as one can be that I was completely unconscious during the entire operation. I remember the surgeon asking me to count to ten, and the specific feeling of my vision melting and swirling around, before suddenly waking up with the surgery over.

When I wake up from dreams, even with no memory of them, I sometimes have "a memory of a memory"; the tip-of-tge-tongue feeling that there's something interesting I'd experienced, but which I now can't remember what it was. But with the anaesthetic, there wasn't anything like that at all.

I was one of the last if not the last patient the dentist who took out my wisdom teeth gave general anesthesia to (at my request, he was normally only doing local). Afterwards, the whole dental office staff (and my mother!) entertained themselves with having conversations with my incoherent self as I came out of the anesthesia. Apparently, I declared that I was ruined and would never be able to sing opera again (point in fact, I had never sang opera before).

Had a few eye surgeries (vitrectomies) under sedation, no pain but lots of flashing lights and lots of kaleidoscope patterns. It was pretty wild.

I was lucky that coming out of sedation was actually fantastic, like the only time I can remember feeling that blissfully relaxed was in maybe a few beach holidays I went on as a kid.

General anaesthetic scares me way more.

I can strongly recommend reading... anything else by Egan, just not that one.

It's not that it's bad. The problem's the opposite: He poses an existentially dreadful question which I can't definitively answer with 'no'.

The doctor who did the surgery was arguably the best doctor I’ve ever interacted with in my 57 years of life. He was horrible at starting appointments on time (much to the frustration of his staff) because he would spend as long as he felt necessary with each patient, regardless of what the scheduled appointment length was. He was essentially at war with insurance companies about coverage limitations (for the procedure, a stapedectomy, insurance companies wanted to have this be an outpatient procedure but he felt it was better for patients not to have to be in a car immediately after surgery so he informed patients beforehand that they would be checking in as an outpatient and he would declare complications after surgery that required an overnight hospital stay. Similarly, the antibiotic that the insurance companies had as their preferred formulary had a tendency to kill hair cells which made it a bad choice for in-ear application. All of his patients were advised that they had an allergy to this antibiotic and thus would have to be prescribed his preferred antibiotic). So, with this doctor, if he told me that the moon was made of green cheese, I would believe him without reservation.

Apparently MJ was taking propofol to sleep, which another commenter said was akin to "getting a haircut by undergoing chemo".

I think there is worlds between definitely defining what consciousness is, and what are some of the scenarios and conditions under which consciousness cannot ever happen.

And on top of that, they put a sedative, just in case.

Towards the end of the article: "the company plans to eventually remove the anesthesia from some brain slices"

Here's hoping the idea is that the slices will be really small, or something, because frankly the whole thing is utterly horrifying enough as-is.

That's before they apply the anaesthetic.

Honestly, there is so much terrible terrible terrible stuff going on in the world and happening to real people, I think it is safe to say that those brains are having a blast. Relatively speaking.

It just invokes a strong emotional response because it's so "abnormal", but if you think about it, there is so much more pain going on where no one bats an eye.

Perfectly avoidable pain even. So it's not even that aspect.

___

OTOH, this is HN, I guess. Having empathy for real people would be harmful to the business model of most people's employers.

So instead, mostly performative outrage/empathy with something that is effectively dead can fill in that gap.

The most important thing to know about anesthesia in the context of OP is that it often doesn't work. 'Anesthesia awareness' is real and probably more common than we think because anesthesia can easily produce awareness but block memory formation.

Keep that in mind when they make arguments about propofol... Which is one of the drugs mentioned in https://www.theatlantic.com/health/archive/2017/12/surgical-... and https://gwern.net/doc/psychology/neuroscience/pain/anesthesi...

https://web.archive.org/web/20120411063647/http://squid314.l...

"What did the doctor say? He told me that they couldn’t up the anesthetic because an overdose could cause respiratory arrest, and that it wouldn’t matter because the anaesthetic on any dose caused severe short term memory loss and whatever happened the patient would forget all about it. The second point, at least, was right on. One patient spent the entire procedure writhing in agony and screaming something incoherent to God. The doctor finished the procedure, took out the endoscope, and cut off the anesthetic, and the patient turned his head, looked the doctor right in the eye, smiled, and said, laughing “Wow, that wasn’t bad at all! Guess I slept right through it!”"

Anesthesia appears to be a fairly broad effect - anaesthetics work on plants, for example [1], even though they lack any neural tissue whatsoever. It would be extremely surprising if those effects were also targeted enough to halt only some types of brain activity.

[1]: e.g. https://doi.org/10.4161/psb.27886

"Anesthesia" is a wider umbrella term than most people realize with many levels of sedation.

Under "general anesthesia", the patient is completely unconscious. They don't respond to any stimuli. In rare cases, some patients may have an adverse reaction and still retain some sensation, but that's very uncommon. My understanding is that we are certain that patients are actually unconscious (and not just unable to respond) because none of the other involuntary responses to trauma occur during surgery: elevated heart rate, etc. In short, you are simply not there for a while. This is what you get for most kinds of significant surgeries unless the surgery requires you to be awake (like brain surgery where they may need to ask you questions).

"Sedation" or "twilight sedation" is a lower level of anesthesia. You are somewhat conscious and can respond to commands from the doctor. But you are unable to form memories of what's happening and you're usually on something like fentanyl that makes you entirely OK with whatever it is they are doing to you. This is common for procedures like colonoscopies and endoscopies where the procedure is somewhat uncomfortable but where you aren't being cut open.

In general, anesthesiologists are trying to balance the goal of patient comfort against the risks of deeper levels of sedation.

More like very rarely (1-2 per 1000), very partially aware. I could not find anything saying that it was common, and it appears cases of actual awareness to the point of having pain / trauma are far rarer still. People who have this tend to have foggy memories or other concrete PTSD symptoms after the fact. It does not appear to be the norm.

I still think this experimentation is absolutely insane and I strongly object because there is no way to get feedback from the "patient" after the fact. Since we have no real idea of what is happening, I believe we should err on the side of caution. "But they could consent beforehand" is not morally acceptable for intrinsically inhumane actions that take away fundamental human rights and dignity. So if you think this is possibly inhumane / potentially torture, it is an irrelevant point since true consent would be impossible.

That's how twilight anesthesia works. That's the kind you get when having something like wisdom tooth removal or an endoscopy. They want you to be responsive to instructions but completely relaxed and unable to form memories of the event.

You're free to stop there. We can also turn it around, and I can ask you for any paper that details the theory of why the brain should be the location of consciousness.

I only gave one example and Wikipedia to start with. There's a lot of material out there if you're (rightfully) skeptical of that one paper. I don't even know what you're refering to as "their theory", as the way I read it, they're basically documenting various co-existing theories, and the authors don't disclose which one they find the most likely. I also don't see it as necessary for science to pick one; it's all about theories. I prefer documentation of all possible theories, and see no reason to dismiss one over the other unless they're disproven. I pointed to that paper, because any paper that talks about alternative theories shows the point I was making: We don't know yet. The point was not to claim that they've managed to put together good or bad arguments.

Can you point me to a paper or other source that proves that the brain is the seat of consciousness? Or that disproves other theories?

I am familiar with the works of Oliver Sacks, Paul Broks, and others, who have spent their lives researching damage to brains and the potential consequences for the psyche. I agree that it sounds like damage to the brain can have big impact, but none of that research, as far as I am aware, proves or even tries to argue that the brain is the only component necessary for consciousness to exist.

I am not interested in beliefs in one theory over another. I am not even asking for probabilities. I am asking for a scientific approach, which is to detail all possible (potentially fringe) theories until they're proven wrong. Anything else is the business of religion.

    Singer, J., & Damasio, A. (2025). The physiology of interoception and its adaptive role in consciousness. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 380(1939), 20240305. https://doi.org/10.1098/rstb.2024.0305

We think that organs can be replaced with little apparent change in consciousness (- this is an active research area, too, by the way). There is also research into how body tissues may form a part of what other theories place exclusively in the brain.

    Aderinto, N., Olatunji, G., Kokori, E., Ogieuhi, I. J., Moradeyo, A., Woldehana, N. A., Lawal, Z. D., Adetunji, B., Assi, G., Nazar, M. W., & Adebayo, Y. A. (2025). A narrative review on the psychosocial domains of the impact of organ transplantation. Discover mental health, 5(1), 20. https://doi.org/10.1007/s44192-025-00148-y

> "Having its own enteric nervous system, sometimes referred to as the “second brain,” the gut is also an immune organ and has a large surface area interacting with gut microbiota. The gut has been shown to play an important role in many physiological processes, and may arguably do so as well in perception and cognition."

    Boem F, Greslehner GP, Konsman JP and Chiu L (2024) Minding the gut: extending embodied cognition and perception to the gut complex. Front. Neurosci. 17:1172783. https://doi.org/10.3389/fnins.2023.1172783

Just remember to be a good father, or things get really epic in a gothic sort of way.

Sure, the key point here is that you die first. Squeamishness is for the living, who have increasingly desperate need of neurological medicines.

My understanding is that after a few minutes without oxygen, the chemistry inside your brain is "fucked up" and even if you get oxygen back it's gone, you're already a vegetable. I like to think that "the state of the machine is gone" but I'm not a doctor

It’s really a solipsistic philosophy. The awkwardness of it was the fact he had a king and the church to appease in his arguments. Willfully forgetting Descartes is one way of dealing with it! (..or plotting a path out of it by reading him as a proto-existentialist)

But take comfort in knowing you are not the void. Cogito ergo sum. It's the only true refute of solipsism.

>> pets are members of people's families!

> If you could only rescue one member from some kind of deadly emergency and they had equal chances, would you prioritize the pet over a human member of your family?

If you could only rescue one family member from some kind of deadly emergency and they had equal chances, would you prioritize a stranger over a member of your family?

Legal/social consequences weight into your question.

A more straightforward angle could be money spent: would someone spend more for the wellbeing of their pet than for a family member (elderlies included).

I would save my cat before a distant cousin I met like four times in my life, absolutely.

How so?

Citation required. Specifically for a western country happening at any notable scale via organ donors.