| Thinking hardly|
or hardly thinking?
|Major trains of thought|
|The good, the bad|
and the brain fart
|Come to think of it|
Mind uploading is a science fictional trope and popular desired actualization among transhumanists. It's also one of the hypothesised solutions to bringing people back from cryonics. It posits that your
soul 'mind pattern' can be implemented in a computer.
The first, and main, problem is that the "mind" isn't a physical thing. "Minds" are emergent properties of living brains. So what you would need to do is preserve is all the electrical, chemical and physical information contained in a living connected-up brain at one particular instant, and then recreate that exact instantaneous set of electrical and chemical data in a new physical substrate and get it set up so that it immediately created the same set of emergent properties. This is not going to happen soon and, perhaps, ever.
Nevertheless proponents typically will say you just need to preserve a dead person's brain, slice it very thinly, scan each piece with microscopes, and reconstruct and run the connections on a computer. With continued exponential improvements in computing, this will soon be possible!
Except it isn't that simple. The brain is not a 'computer' as such, and the neurons are much more complicated than the simplified 'neurons' of machine learning. It isn't feasible to preserve a dying brain before cell death destroys much of the information you are trying to get. Even if it were, preservation techniques only allow one to see the structure of the connections between neurons, but further electrical and chemical detail is lost.
The brain, like any organ, works via biochemistry. It doesn't have a standardized computer architecture whereby you can download data. Vital information of the distribution of various molecules and how they are distributed and interact needs to be recorded, but this is heavily damaged by any preservation solution. There does not appear to be a way, even in theory, to preserve the biochemistry in a readable state. Not only that, but the brain is a wet, organic analogue processor; it will certainly not be possible to copy it to dry, inorganic digital silicon without massive changes to the enormous amounts of data you would need to obtain.
As biologist PZ Myers - who freezes zebrafish brains a whole lot, and would be delighted to have anything recoverable at the end - explained:
“”We don’t have a method to lock down the state of a 1.5kg brain. What you’re going to be recording is the dying brain, with cells spewing and collapsing and triggering apoptotic activity everywhere. And that’s another thing: what the heck is going to be recorded? You need to measure the epigenetic state of every nucleus, the distribution of highly specific, low copy number molecules in every dendritic spine, the state of molecules in flux along transport pathways, and the precise concentration of all ions in every single compartment. Does anyone have a fixation method that preserves the chemical state of the tissue? All the ones I know of involve chemically modifying the cells and proteins and fluid environment. Does anyone have a scanning technique that records a complete chemical breakdown of every complex component present?
Additionally, computer emulations of brain activity, even if it was just the connections between neurons, are not going to be affordable. This means that the price of computing cannot keep falling like it has, so the enormous supercomputers that would be required to run any uploaded mind would be unaffordable, even in the future.
It seems likely that the best and most efficient medium for running a human mind is a human brain, so keep yours in good working order.
The less crazy transhumanist think that brain uploading would involve cutting up the brain.  The more crazy guys think that nanotech would allow a slow and steady replacement of brain's tissue to the computing substrate. 
Several metaphysical questions are brought up by the prospect of mind uploading. Like many such questions, these may not be objectively answerable, and philosophers would no doubt continue to debate them even if uploading somehow became a reality.
The first major philosophical question is more or less falsifiable: whether consciousness is artificially replicable in its entirety. In other words, assuming that consciousness is not magic, and that the brain is the seat of consciousness, does it depend on any special functions or quantum mechanical effects that cannot ever be replicated on another substrate? This question, of course, remains unanswered although, considering the current state of cognitive science, it is not unreasonable to think that consciousness will be found to be replicable in the future.
Assuming that consciousness is proven to be artificially replicable, the second question is whether the "strong AI hypothesis" is justified or not: if a machine accurately replicates consciousness, such that it passes a Turing Test or is otherwise indistinguishable from a natural human being, is the machine really conscious, or is it a soulless mechanism that merely imitates consciousness?
Third, assuming that a machine can actually be conscious (which is no great stretch of the imagination, considering that the human brain is essentially a biological machine), is a copy of your consciousness really you? Is it even possible to copy consciousness? Is mind uploading really a ticket to immortality, in that "you" or your identity can be "uploaded"?
Advocates of mind uploading take the functionalist/reductionist approach of defining human existence as the identity, which is based on memories and personalities rather than physical substrates or subjectivity. They believe that the identity is essential; the copy of the mind holds just as much claim to being that person as the original, even if both were to exist simultaneously. When the physical body of a copied person dies, nothing that defines the person as an individual has been lost. In this context, all that matters is that the memories and personality of the individual are preserved. As the recently murdered protagonist states in Down and Out in the Magic Kingdom, "I feel like me and no one else is making that claim. Who cares if I've been restored from a backup?"
Skeptics of mind uploading question if it's possible to transfer a consciousness from one substrate to another, and hold that this is critical to the life-extension application of mind uploading. The transfer of identity is similar to the process of transferring data from one computer hard drive to another. The new person would be a copy of the original; a new consciousness with the same identity. With this approach, mind uploading would simply create a "mind-clone" — an artificial person with an identity gleaned from another. The philosophical problem with uploading "yourself" to a computer is very similar to the "swamp man" and teleportation thought experiments.  Suppose
Alec Davidson goes hiking in the swamp and is struck and killed by a lightning bolt. At the same time, nearby in the swamp another lightning bolt spontaneously rearranges a bunch of molecules such that, entirely by coincidence, they take on exactly the same form that Dr. Holland's Davidson's body had at the moment of his untimely death. This being, whom Davidson terms Swamp Thing "Swampman," has, of course, a brain which is structurally identical to that which Davidson had, and will thus, presumably, behave exactly as Davidson would have. He will walk out of the swamp, return to Davidson's office at Berkeley, and write the same essays he would have written; he will interact like an amicable person with all of Davidson's friends and family, and so forth. This is one reason that has led critics to say it's not at all clear that the concept mind uploading is even meaningful.  For the skeptic, the thought of permanently losing subjective consciousness (death), while another consciousness that shares their identity lives on yields no comfort. Daniel Dennett, in Consciousness Explained, has called into question the validity of these sorts of thought experiments altogether, maintaining that when a thought experiment is too far removed from the actual state of affairs, our intuitions cease to be meaningful.
Consciousness is currently (poorly) understood to be an epiphenomenon of brain activity — specifically of the cerebral cortex. Identity and consciousness are distinct from one another — though presumably the former could not exist without the latter. Unlike an identity, which is a composition of information stored within a brain — it is reasonable to assume that a particular subjective consciousness is an intrinsic property of a particular physical brain. Thus, even a perfect physical copy of that brain would not share the subjective consciousness of that brain. This holds true of all 'brains' (consciousness-producing machines), biological or otherwise. When/if non-biological brains are ever developed/discovered it would be reasonable to assume that each would have its own intrinsic, non-transferable subjective consciousness, independent of its identity. It is likely that mind uploading would preserve an identity, if not the subjective consciousness that begot it. If identity rather than subjective consciousness is taken to be the essential, mind uploading succeeds in the opinion of mind-uploading-immortalist advocates.
Mind uploading has also ethical issues, especially in what refers to duplicates of a given self, as well as others relatives to the harmful things that could be done on what basically would now be an equivalent of a computer file or program, and that (at least for now and at least not so easily too) cannot happen in a human mind -namely, erasing it or destroying the computer that is running the simulation/storing the uploaded mind killing for good the person, modifying its contents deleting and/or adding others, merging two or more previous selves into other and vice-versa, being copied or moved ad infinitum, messing with inputs (sort of sending someone to a "digital heaven" or a "digital hell" -or worse-), messing with the way time is felt by the uploaded speeding or slowing the simulation (or causing it to enter into an infinite loop), infecting a mind with the equivalent of a computer virus (or rather the equivalent of a neurological disease)... the list goes on-.
Believing that there is some mystical "essence" to consciousness that isn't preserved by copying is ultimately a form of dualism, however. Humans lose consciousness at least daily, yet still remain the same person in the morning. In the extreme, humans completely cease all activity, brain or otherwise, during deep hypothermic circulatory arrest, yet still remain the same person on resuscitation, demonstrating that continuity of consciousness is not necessary for identity or personhood. Rather, the properties that make us identifiable as individuals are stored in the physical structure of the brain.
Ultimately, this is a subjective problem, not an objective one: If a copy is made of a book, is it still the same book? It depends if you subjectively consider "the book" to be the physical artifact or the information contained within. Is it the same book that was once held by Isaac Newton? No. Is it the same book that was once read by Isaac Newton? Yes.
- Collection of articles on mind uploading
- Welcome to Life — The Singularity, Ruined by Lawyers.
- Against Naive Uploadism: Memory, Consciousness, and Synaptic Homeostasis, Seth Weisberg, H+ Magazine
- Why Transhumanism Won't Work, The New Atlantis (A misleading title, the article is about mind uploading, not transhumanism in general)
- Brain vs Deep Learning Part I: Computational Complexity — Or Why the Singularity Is Nowhere Near (an article examining the technical feasibility of strong AI)
- And everyone gets a robot pony!, PZ Myers.
- Reconstructing a brain, PZ Myers.
- We’ll get brain-uploading about the time we get teleportation, PZ Myers.
- How can you protect a brain by destroying it?, PZ Myers.
- Will You Ever Be Able to Upload Your Brain?, Kenneth D. Miller.
- SMBC answers swamp man.
- Mind Uploading and The Teleportation Problem April 16, 2015, Isidore MacDubh
- Meet Bina-48, an artificially intelligent 'mind clone', Dylan Love, Feb 9, 2015
- Downloading Consciousness: Philosophical Issues, Stanford University
- Davidson, Donald (2001 (1987)). "Knowing One's Own Mind" Reprinted in Subjective, Intersubjective, Objective (pp. 15–38). New York and Clarendon: Oxford University Press. Originally published in Proceedings and Addresses of the American Philosophical Association, 60 (1987), 441-58.
- Bjorn Merker (2007). Consciousness without a cerebral cortex: A challenge for neuroscience and medicine. Behavioral and Brain Sciences, 30, pp 63-81 doi:10.1017/S0140525X07000891
- Neurologic Recovery after Prolonged Circulatory Arrest in Surgery for Aortic Dissection December 2008 DOI: 10.1532/HSF98.20081067 "The patient's head was packed in ice to facilitate maintenance of brain hypothermia. Her average systemic temperature during the third period of circulatory arrest was 22.5 degrees C. Extensive neuropsychologic testing, which was performed to assess the patient's cognitive functions and abilities at 4-month follow-up, showed an absence of global cognitive decline and only a moderate impairment of attentional capacity. Overall cognitive functioning was within the normal range and did not interfere with everyday activities or quality of life."