When thinking of trans-humanism it's fairly common to find in fiction the idea of mind uploading, brain emulation, etc. But I was wondering how would it be possible to relocate a conscious mind to another, synthetic, body.

Picture something like this: In a distant future a human goes to the "mind relocation facility" where:

  • first, a synthetic replica of their body is created;
  • second, their brain is somehow connected to the body's synthetic substrate;
  • third, relocation takes place whilst the individual is perfectly conscious and as such can feel this migration happen in real time (this is important to make sure the individual is still the same person).

In other words, this would imply abandoning one's organic body to adopt a synthetic one that emulates the former's functions (to what degree, I don't know).

It sounds like an awfully complicated thing to do, so I suppose the first question to ask is: would something like this even be possible? If so, in what ways could it work? and would it work, perhaps, with a body that's not a perfect replica of the one being abandoned?

Not looking necessarily for hard science-fiction answers as I'm assuming that with currently known technology this is impossible. But really, I'm specifically interested in:

  • A, whether it violates any known laws (aka: is this stupid?), and:
  • B, would this even be a good idea or are the alternatives better?

Would also be interested to know if there's any examples of a similar concept being described in fiction.


  • 1
    $\begingroup$ I think a process identical to this is described scene-by-scene in Old Man's War by John Scalzi $\endgroup$
    – Halfthawed
    Jan 8, 2020 at 0:13
  • 1
    $\begingroup$ Moving a file across filesystems implies making a copy and then deleting the original. I strongly suggest a similar protocol be used for moving a mind from one brain to another, to mitigate the risk that a error in transfer results in an inoperable mind. A full backup taken before initiating the procedure is also recommended. $\endgroup$
    – AlexP
    Jan 8, 2020 at 0:24
  • $\begingroup$ Kiln People is a great high SF by David Brin. You do not abandon your meat but you can make temporary copies to augment yourself. They are color coded to correspond with the tasks they will likely have to do. Each one is you. $\endgroup$
    – Willk
    Jan 8, 2020 at 0:38
  • $\begingroup$ I don’t want to say too much because parts of my own work cover this topic and I have a few terrifying secrets up my sleeve. I will admit however that in my case the character in question undergoes what you describe because they simply have no choice under the circumstances. How it’s achieved is utterly unique in sci-fi (I hope) and crucial to the plot. One of many functions of the overriding synthetic mind’s responsibilities is applying physical and mental restraints limiting memory. Due to stress and potential longevity the physical manifestations of psychological trauma can be lethal. $\endgroup$ Jan 8, 2020 at 1:07
  • $\begingroup$ I think the important, and hardest part, is avoiding the cliches and tropes that surround ‘insert AI here’. On the surface one of my characters might sound like a tag-along synthetic but that’s not the case at all. My goal is to crush the stupid modern trends when it comes to AI. Yours should be too. $\endgroup$ Jan 8, 2020 at 1:10

5 Answers 5


The classic example here is perhaps Hans Moravec's early ideas on mind transfer and brain simulation. I'm not sure if he gave the procedure a name (as I haven't read the original work) but it is not unreasonable to call it Moravec uploading or migration.

You will need: a system, hardware or software, capable of simulating a human brain. This is quite a tall order, but handwave away. Next, you will need a nanomechanical system that inserts a bunch of nanoscale wires into the head of the migrant, These will go in as a small number of large cables, but branch and move into place by themselves once they've been stuck in. At the end of each wire is a nanoscale system that is inserted into a braincell, records its useful contents (handwave, handwave) and builds a model of the behaviour of the cell (handwave) as its owner thinks. Probably the owner will need to be in a special virtual environment designed to trigger all sorts of mental activity to maximally exercise their brains during the process.

As the behaviour of a cell becomes modelled fully, further nanowires are inserted into the other brain cells to which the original cell was connected, and the job of sending and acting upon neural signals is taken over by the brain-simulation hardware or software.

The process then proceeds smoothly through the migrant's brain, replacing functionality braincell by braincell, so gradually that the migrant continues their thread of consciousness uninterrupted. Ideally, they should not even notice the procedure is ongoing, though they might guess as to which bits of their brain are being worked on by what their virtual environment is getting them to do (run! jump! play chess! re-enact that really embarassing moment with your first boyfriend and the cucumber!) but other than that they can just remain in the system until the migration in complete and then they will leave the virtual environment and see that they are now in a new body.

I suppose the first question to ask is: would something like this even be possible?

We don't actually have a good idea about how brains work, or even what intelligence or consciousness is. The odds seem good that they are not magical processes, and as such it should be possible to replicate them using non-magical means. So it is probably possible.

would it work, perhaps, with a body that's not a perfect replica of the one being abandoned?

That's probably a dangerous thing. There are various kinds of dysmorphia where a person can have serious psychological issues with some aspect of their body. The closer it was to their original body the better. You can always make progressive changes after you've got rid of the hard-to-maintain fleshy bit.

Of course, if you've hadnwaved in mind editting then you can fix this just fine.

A, whether it violates any known laws (aka: is this stupid?), and:

Nah, but the problem is clearly hard. Brains are complex. The whole connectome would need to be understood and duplicated, at least well enough that the migrant didn't notice the edits. Quite how high tech this is would be hard to say, but the answer is probably very and we won't be there for a while.

B, would this even be a good idea or are the alternatives better?

There are alternatives, but they are likely to prove unsatisfying for many people. Various scifi settings have backups and duplicates, but it might be hard to see those as yourself rather than other people who are increasingly unlike you or (perhaps worse) a compelling simulation of you being worn like a sockpuppet by an uncaring AI.

Other upload (or at least mind expanding) ideas exist, but they don't necessarily accomplish what you want, and if you want this sort of mind-transfer in your setting then you can feel free to handwave it in. You're the boss!


Completely unknownable

Note that the answer I give isn't that a mind uplink to a synthetic mind is impossible. It's just that we currently don't have any idea how it might be done. Theoretically, it may be possible. If we draw a box outside around the human brain, we can call this box a 'closed system'. Furthermore, this 'closed system' is based in the material world. (Presumably - the jury's still out on that.)

Thus, any thing created by the material world in a closed system can be recreated in a closed system. Or, in other words, we don't have any proof that it's impossible to upload a human mind. The problem is we don't really understand how consciousness works within the brain (why you feel an 'I', in other words), so from a purely observational, secular perspective, it might be possible, but we don't know how if it is. (That is, I'm ignoring souls right now because they're hard to interact with from a scientific perspective.)

There have been links to the electrical current running through the brain, so perhaps we can do it via a network of wires. Perhaps we'll be able to one day artificially grow nerve bridges between the brain and this new 'synthetic brain' to allow the human consciousness to move. Maybe we'll just be able to scan a human brain with a complicated array of different magnetic fields and figure out a program to replicate the brain off of that. But we just don't have enough information now to guess how to plausibly do it.


This process should be possible within the realm of science fiction. It would probably involve high levels of nanotechnology. After creating the synthetic body, nanorobots would surgically disconnect your spinal cord from the base of your brain without causing damage to it. They'd start disconnecting other nerves as well, and your brain would be de-skulled while they continue to provide oxygen to it so that no damage occurs with that.

At this point, I'm not sure if they can remain conscious. You suddenly become deaf and blind, while also experiencing absolute numbness? Might be psychological issues here, especially if that persists for very long. Assume that there are none though. This brain continues to have blood (possibly artificial) circulated within it while being transferred into an appropriately-sized volume in the artificial body (doesn't necessarily have to exist within the head of that body).

The body will have a mechanism for oxygenating the (artificial, most likely... otherwise we need to also keep marrow) blood, and for supplying nutrients into it and removing waste. The stubs for the optic nerves and others will be attached to some sort of neural interface. This probably happens in the reverse order that they were disconnected.

It's unclear how similar the new body has to be to the old one. As people age, their bodies change and while this causes some emotional/psychological distress, that's usually tolerable and many become accustomed to it. Additionally, we've got decades of various organ transplant cases under our belts, and those don't seem to be very traumatizing (even face and hand transplants, recently).

Without a proper theory of consciousness or artificial intelligence, I contend that it's impossible to know how mind-uploading would or could work. Is the neuron the smallest unit of intelligence? I've read some fringey science over the years that suggests there may be cellular organelles within the neuron that are that. Is the neuron primarily electrochemical in nature? Again, some fringey science has suggested that neurons transmit signals via sound (the signals do indeed propagate at a speed similar to sound in tissue). There is a man who due to congenital problems has brain matter at about 15% that of typical humans, and he holds a civil service job in France, has an average IQ. Some people have reported after organ transplants (hearts, kidneys, etc) feeling as if they were the donor, though those reports are dismissed as psychological issues.

So we can't even figure out the basic biological issues here. What of the software, the part that makes us "us"?

If you make two copies, are they both the person that was copied? If you make a copy but keep the original, is the copy also the person? Does there need to be an uninterrupted continuity, if so what happens if you pause the copy and don't activate it for a minute? Or a day? Or a century? Are you currently an uninterrupted consciousness? What then of our dreams of suspended animation? Is consciousness even a Turing-computable phenomenon? Philosophically we posit that since we can simulate elementary particles, doing so for an entire brain would necessarily create a consciousness just as exists in a real brain... but in truth we can't simulate a brain. Or, as it turns out, even just a handful of elementary particles. Humans might be natural hypercomputers. Though, again we're veering into fringe science hokum with that.

As for legal implications, we should assume two probable avenues of exploration (likely in parallel). Military uses would be obvious... put a soldier's brain into some unstoppable robot. This first option will likely occur in secret and quite possibly in contravention of established law. The second will be for medical purposes, perhaps therapeutically for quadriplegics trapped in an unresponsive body. Given the nature of their predicaments, this will mostly pass medical ethics supposing that the technology is sufficiently advanced and tested that the likelihood of success is high.

Legally, there will be no laws against this. There are none now that would prevent it, and it's difficult to imagine scenarios that would invite legislation prohibiting it. So mostly it's a question for the medical ethicists. Prosthetics aren't just considered ethical, but essentially mandatory. Full-body prosthetics would be no different.


The complexity of the process described in this video shows the technological challenges https://youtu.be/2DWnvx1NYUA

A second challenge: when you upload your mind, is it you or someone else like you? The following thought experiment brings up the paradox created when you upload the mind into a "copy" without destroying the original: https://youtu.be/0X9bkylsuEU

"I'm still that cancer patient waiting to be uploaded"

No, you are the new you, see this man?

It's another copy! That's not me!

We're not done yet. We copied you and we must destroy the original.

What? You're gonna kill me? What's the point in doing this? I'm going to die in a few weeks anyway! Let me live my last days in peace and be with my family!

So the first step in uploading is first of all finding what defines "you" as yourself, and not someone else. That's sort of where your "soul" or whatever defines who you are. Let's call these the soul cells.

The body and mind are scanned. Let's say we have the technology. We scan all but the soul cells. We build that longed-for synthetic body of your choice (which might be a new flesh-and-blood body, a computer or whatever). The "hole where your soul should be" is the "socket".

Next, we do a surgical extraction of the soul cells. We make sure they are kept alive throughout the transfer phase. They are inserted into the "socket". The socket allows the soul cells to connect their synapses to the neighboring cells (or artificial support) and be fed by blood vessels.

As a conclusion, the soul cells must be sustained and take part in the transfer. It is possible to devise ways to maintain those cells indefinitely via advanced nano technology. Replicating them via uploading is not going to work. You must "cut and paste" and not "copy and paste". Once the soul cells are sustained, we can tweak their genetic and amino acids make-up to turn them into synthetic immortal cells.


Out of pure coincidence I've also had this concept in mind for a while. What I'm using for reference is the Ship of Theseus, take a boat, replace its parts and ask yourself is it still the same boat? Whats interesting is that the human body itself is like theseus' ship, constantly replacing itself. However it should be noted that brain cells aren't always replaced as they contain memory.

would something like this even be possible? Yes. With proper knowledge this could happen. Is it realistic? Not yet.

In what ways could it work? If you were to copy and paste memories into a synthetic brain it would simply be a copy and not a transfer, so the way you should go about is to synchronize the human brain with the synthetic one. You can use handwavium to explain how that's done. What matters is that the human subjects brain functions are mirrored and experienced in both minds. The human has two bodies and one mind, which will no doubt be a disorienting experience. Whats left to do after that is to instantly destroy the human brain, leaving the synthetic brain with the subjects mind. Note: It needs to be destroyed, otherwise simply severing the link will create a double. Think of it as losing a lobe of your brain, your still the same person (although some changes might occur).

Would it work, perhaps, with a body that's not a perfect replica of the one being abandoned? As long as the brain is identical in structure to the human brain this is possible. Other than that any augmentation on the cellular or physiological level is possible since the body is nothing but a meat puppet, a vessel for the mind so to speak.

One a side note, don't think that your idea is stupid "A, whether it violates any known laws (aka: is this stupid?)". People are so accustomed to the real (normal world) that they have trouble understanding fictional ones. I face this fact every day.


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