Jump to content

Recommended Posts

This is a fascinating NY Times article about recent success by researchers in restoring metabolic function to a recently severed pig brain, retrieved from a slaughterhouse. Very Frankenstein-esque, but for real. Here is one of the most interesting paragraphs, along with a link to the Nature article [1] about the research. 

By any measure, the contents of the paper Sestan and his team published in Nature this April were astonishing: Not only were Sestan and his team eventually able to maintain perfusion for six hours in the organs, but they managed to restore full metabolic function in most of the brain — the cells in the dead pig brains took oxygen and glucose and converted them into metabolites like carbon dioxide that are essential to life. “These findings,” the scientists write, “show that, with the appropriate interventions, the large mammalian brain retains an underappreciated capacity for normothermic restoration of microcirculation and certain molecular and cellular functions multiple hours after circulatory arrest.”

The researchers are understandably conservative. They utilize blockers to keep neurons from firing in any coherent way, although they did observe spontaneous neural spiking (see abstract below).

They also acknowledge that less scrupulous (or more ambitious, depending on your perspective) researchers could quite concieveably attempt to restore normal neural activity to the harvested brain. They also say that pig anatomy isn't that different from human anatomy, so the same technique (with some modifications) should work for a human brain, should anyone be bold enough to try it.

Pretty amazing to think that someday a "brain in a vat" scenario might actually become reality. Without any sensory input or motor output, it would probably be a very unpleasant experience, if it would be conscious at all.

--Dean

---------------------------

[1] Nature. 2019 Apr;568(7752):336-343. doi: 10.1038/s41586-019-1099-1. Epub 2019 Apr
17.

Restoration of brain circulation and cellular functions hours post-mortem.

Vrselja Z(1)(2), Daniele SG(1)(2)(3), Silbereis J(1)(2), Talpo F(1)(2)(4),
Morozov YM(1)(2), Sousa AMM(1)(2), Tanaka BS(5)(6)(7), Skarica M(1)(2), Pletikos 
M(1)(2)(8), Kaur N(1)(2), Zhuang ZW(9), Liu Z(9)(10), Alkawadri R(6)(11), Sinusas
AJ(9)(10), Latham SR(12), Waxman SG(5)(6)(7), Sestan
N(13)(14)(15)(16)(17)(18)(19).

The brains of humans and other mammals are highly vulnerable to interruptions in 
blood flow and decreases in oxygen levels. Here we describe the restoration and
maintenance of microcirculation and molecular and cellular functions of the
intact pig brain under ex vivo normothermic conditions up to four hours
post-mortem. We have developed an extracorporeal pulsatile-perfusion system and a
haemoglobin-based, acellular, non-coagulative, echogenic, and cytoprotective
perfusate that promotes recovery from anoxia, reduces reperfusion injury,
prevents oedema, and metabolically supports the energy requirements of the brain.
With this system, we observed preservation of cytoarchitecture; attenuation of
cell death; and restoration of vascular dilatory and glial inflammatory
responses, spontaneous synaptic activity, and active cerebral metabolism in the
absence of global electrocorticographic activity. These findings demonstrate that
under appropriate conditions the isolated, intact large mammalian brain possesses
an underappreciated capacity for restoration of microcirculation and molecular
and cellular activity after a prolonged post-mortem interval.

DOI: 10.1038/s41586-019-1099-1 
PMID: 30996318 
 

Share this post


Link to post
Share on other sites
On 7/3/2019 at 4:25 PM, Dean Pomerleau said:

Pretty amazing to think that someday a "brain in a vat" scenario might actually become reality. Without any sensory input or motor output, it would probably be a very unpleasant experience, if it would be conscious at all.

It would be the purest definition of hell!!!

Share this post


Link to post
Share on other sites
24 minutes ago, mccoy said:

It would be the purest definition of hell!!!

Probably. But then again, the psyche is amazingly resilient and adaptive. Isolation isn't always crippling. For example, Buddhist monks have been known to spend years cut off from the world meditating alone in a cave and come out quite happy, e.g. her

Incredibly, at least some people with locked-in syndrome learn to cope and enjoy their existence:

It is clear PK loves life and wants to live. He makes every effort to be happy in his imprisoned existence. A former agnostic, he now acknowledges the existence of God, who gives him strength and the will to live.

So I wouldn't rule out someone being ok with existing as a brain in a vat, at least for a while. Particularly if they are well-adjusted ahead of time, know they are going to die soon anyway, have volunteered for it and are excited to work with researchers conducting the experiment to explore the frontier of science and life extension, e.g. to work out an effective means of communication with the outside world.

The Diving Bell and the Butterfly is an amazing book and movie along these lines.

--Dean

Share this post


Link to post
Share on other sites

Dean, your points remind me of a case of a person in a semi-conscious coma for years, who then awoke and described that he was conscious, but locked in.

It amazed me that he did not speak of hell, but he said that he took refuge in a subjective world of dreams and fantasy. 

The brain has apparently unfathomed resources. To most of us that state would now be excruciating hell, but then the adaptive response as you say may be totally different, although I'm not exactly looking forward to a similar experience.

The book you suggested appears compelling, I didn't know it.

Share this post


Link to post
Share on other sites

Not sure why you'd call it "excruciating hell".  We are talking about something that doesn't even exist (ability to keep a brain, detached from a body, alive indefinitely) but it's not hard to imagine a day when this exists.  I think you are thinking about it in the wrong way.  In my vision, existence would be both satisfying and "virtual" as in "virtual reality", we'd need a way to interface with the visual cortex, and mastery of brain stimulation to simulate touch/orgasm/etc but all of those things are theoretically possible.  If you've seen the movie "Ready Player One" or even "The Matrix" you can get a sense of what things could be like.  Also remember there are lots of people who think we are already living in a simulation.

Edited by Gordo

Share this post


Link to post
Share on other sites

Gordo, 

I agree such a virtualized existence could be pretty cool if rich enough. What I characterized as "probably very unpleasant" and McCoy "the purest definition of hell" was being a brain in a vat without any sensory input or motor output. 

--Dean 

P. S. Count me as one of camp who seriously entertains the notion that we could already be living in a created computational reality, whether it should be characterized as "simulated" is a matter of semantics, as philosopher David Chalmers discusses in this video

 

Share this post


Link to post
Share on other sites

Well, we ALREADY have Brain–computer interfaces so the "early volunteers" should, even today, be able to say "this sucks, pull the plug" if they need to, haha.

If I knew I was going to die imminently (like advanced stage, untreatable cancer) I would definitely consider volunteering for something like this even at the early stages with no special "virtual reality" or visual cortex activation (i.e. without any sensory input or motor output), assuming there was at least some reasonable expectation that consciousness could be maintained, that it would not be a constant state of pain, that communication would be possible, and that brain survival was expected to last more than a year (who wants to volunteer to go though this only to live for days or weeks).  In other words, I would not go first.  I like dreaming, and I would consider this a permanent "dream like state".  I also have a good imagination.  Granted, this would not be a preferred state of being by any stretch... but if you believe the odds of an "afterlife" are low, its not hard to come to the conclusion that such a state would still beat "never existing again, period, for all eternity".

This is me in a brain vat, with my imaginary friend:

image.thumb.png.513cf26321a7cd1d874b96bab1b92198.png

Edited by Gordo

Share this post


Link to post
Share on other sites

Yes, probably retiring one's consciousness in dreamland while deprived of sensory and motor input would maybe constitute a natural adaptation and defense of a brain in a vat.

Meditation: that's harder, very few people are able to meditate extensive hours with a still and relaxed mind. I've been trying for decades and such an expanded state of consciousness is still eluding me.

Share this post


Link to post
Share on other sites
On 7/9/2019 at 3:00 PM, mccoy said:

Meditation: that's harder, very few people are able to meditate extensive hours with a still and relaxed mind. I've been trying for decades and such an expanded state of consciousness is still eluding me.

You should try the Griffiths protocol for meditation. Delivered an expanded state of consciousness for 96% of participants.

Edited by Gordo

Share this post


Link to post
Share on other sites
14 hours ago, Gordo said:

Griffiths protocol for meditation. Guaranteed to deliver an expanded state of consciousness.

Gordo, that depends on what you mean by 'expanded state of consciousness'. 

Breathing techniques are part of many meditation teachings, but they are but a tool to an end. The end is extremely hard to achieve.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×