In a 2015 issue of Giga Society's journal "Nemesis", leaked back in time by Giga member and Time Lord Dr Whence, I found this letter:
While exploring future developments in the field of "Life Extension" I came accross a bizarre form of "immortality", realized in the late 22nd century. In addition to convential treatment with anti-oxidants and the like to slow down cell aging, one appears to have found a method to transpose an individual's self-awareness - the "I" or "mind" or "soul", if one likes - into a man-made silicon-based substrate.
This involves high-tech brain surgery; artificial neural networks, consisting of "chips" but structured to be compatible with biological tissue, are inserted into the brain and microscopically connected to individual neurons, to thus expand the cortex. These brain extensions are unprogrammed and neutral in structure; during the months following the operation the brain "takes them into use", just as normal neurons are employed, e.g. in early life or after brain damage. The patient experiences nothing abnormal, as the new networks, though silicon-based, behave exactly like natural tissue when it comes to processing incoming electric signals. These signals come from artificial synapses, carefully connected by the surgeon to thousands of neurons. Each artificial network contains around a hundred million virtual neurons, ten thousand of which receive, via the artificial synapses, impulses directly from the biological brain. Twenty of these networks are implanted in different locations in the cortex. The period following the operation is comparable to that after a mild stroke, when functions of damaged tissue are taken over by other parts of the brain; except that there is no damage.
Once the brain has incorporated the extensions and the neural activity is equally spread over old and new tissue, the twenty networks are electrically connected to a supernetwork containing ten to the twelfth virtual neurons, temporarily built-in in the chest; a new brain.
Over the course of several years, the brain functions gradually get to employ parts of the new brain. A situation evolves where the neural activity is divided over the two brains, that work as one. In this stage, only a fraction of the gigantic new brain is yet in use. The patient has hardly or not noticed the process, since it does not differ from the natural development of brain activity throughout life.
When the patient is approaching his natural death, the biological brain is, in phases, destroyed by means of subcranial injections. Each time a section has been eliminated, some time is allowed for the new brain to take over that section's functions, if this had not already taken place. Finally, about five years after the initial operation, the patient's neural activity is restricted to the artificial substrate. His awareness, his "self", occurs exclusively in the silicon-based virtual network. Now the new brain is logged in on a large supercomputer that supplies virtual sensorial information and a virtual world to live in. The new brain is removed from the body, and the body is cremated. The patient's mind has survived his physical death.
The virtual environment of the supercomputer called "Thoth" is temporary. Thoth conducts a thorough survey of each entering soul, to decide its final destiny. To that purpose, Thoth scans the soul's memory, which has the effect of seeing one's life roll by. Thoth then counts the number of times one has spoken the truth despite inherent discomfort and regardless of consequenses. If this suffices, one is allowed to enter a hypernetwork called HEAVEN.COM. One can associate there in virtual hyper-reality with other truthful and righteous individuals who passed the Test Of Thoth. And finally, finally, finally there will be the compensation for years, decades and centuries of living amongst liars, cheaters and worse; finally the cruel joke called "life" turns into an eternal state of truth, reason and understanding. And of course there are links to Internet, in case one still wishes to communicate with the outside world. These minds with their powerful new brains though will eventually evolve into entities of superhuman intelligence and lose interest in "the undead", as they begin to call us. Still, for Time Lords it could prove worthwhile to keep track of them, as their possible new insights might be instructive.
On the other hand, if one does not "make the grade", if one has not been truthful to Thoth's satisfaction, Thoth calls a delightful little program named FLAMINGHELL.EXE, that creates one a virtual environment to see to it one spends one's eternity in an appropriate manner. There is justice for everyone in Thoth. I have asked Thoth, "Why divide humanity?", and his answer was, "Humanity divides itself; I merely confirm the choice the individual has already made during physical life".
It is interesting to mention this method of gradually transposing the mind into an artificial substrate and providing it with a "hereafter" was conceived as early as in the late 20th century by [name illegible, scrambled when it was sent back in time to me, PC], who first published it in an IQ journal named [scrambled again, PC]. So how [rest of letter scrambled, PC]
Fascinating! I've seen more speculations on transposing your mind into a computer, but the big problem always was: even if you succeed in making a sufficiently complex neural network that is a copy of your brain, and even if awareness and "self" occur in it... it isn't you!! It's a copy of you. Your "own" consciousness would not "jump over" into the computer, but a second "self" would come into being. This is the ultimate problem of AI and immortality.
And from Dr Whence' report we know this problem will be solved! And how brilliantly! If only I had a tenth of that person's genius... A pity the name got scrambled, but these things happen in time travel. The late 20th century he writes! Who could that be? What IQ journal? Let's read them all carefully, it must be one of these days this method will be published!
And how instructive yet frightning to learn there will be two paths to go by for the new-brained mind. On the other hand, would not life be too cruel a joke if there would not be some form of compensation? But for the moment we can only hope the Life Extension methods that will become available during our life spans will bring us to the late 22nd century, so that we can participate in this breathtaking project of immortality.