31 July 2012

You Might Try to Perfect the Technique With Insect Brains First

Is it possible to preserve who you are, after you die? There are large numbers of serious people who spend their time devising ways to do just that. There are those who plan to freeze their brains, those who want to upload their brains into a "more permanent" repository of consciousness, and there are those who wish to dismantle their own brains -- piece by piece -- in order to build a replica of all brain cells and connections to a level of precision unimaginable today.

They would call that replica, "Themselves, version II."
"There is only one truly interesting problem in science and technology," [Sebastian] Seung writes, "and that is immortality."

His tone, in the book and in conversation, is that of an open-minded skeptic. Of brain preservation, he says simply, "it's possible" but not imminent. As for immortality, he's quite sure that he'll die, just as we all will. The discussion about these issues has reached an impasse, he explains. Until someone dead is brought back to life, "it's just your word against mine, a philosophical debate." But connectomics can provide a way forward, he says.

Seung proposes a two-part test. First, is it true that we are our connectomes? Second, does cryonics or chemical brain preservation keep the connectome intact? If either statement is false, then freezing or uploading can't work. If both statements are true, immortality isn't in the offing, he cautions, but it's at least plausible. "Some colleagues may think this is all kind of crazy," he says, "but these questions can be addressed in an intellectually rigorous way." _Chronicle of Higher Ed_via_NBF

Seung is responding to the ideas of Ken Hayworth, a man who believes that he has found a way to live forever. Hayworth plans to peel his brain -- at the moment of death -- to a very thin level with a microtome. The peeled brain will be preserved, then analysed to an exquisite level of detail, and then "reproduced" precisely.

More on Hayworth's bold ideas:
He wants his 100 billion neurons and more than 100 trillion synapses to be encased in a block of transparent, amber-colored resin—before he dies of natural causes.

To understand why Hayworth wants to plastinate his own brain you have to understand his field—connectomics, a new branch of neuroscience. A connectome is a complete map of a brain's neural circuitry. Some scientists believe that human connectomes will one day explain consciousness, memory, emotion, even diseases like autism, schizophrenia, and Alzheimer's—the cures for which might be akin to repairing a wiring error. In 2010 the National Institutes of Health established the Human Connectome Project, a $40-million, multi-institution effort to study the field's medical potential.

Among some connectomics scholars, there is a grand theory: We are our connectomes. Our unique selves—the way we think, act, feel—is etched into the wiring of our brains. Unlike genomes, which never change, connectomes are forever being molded and remolded by life experience. Sebastian Seung, a professor of computational neuroscience at the Massachusetts Institute of Technology and a prominent proponent of the grand theory, describes the connectome as the place where "nature meets nurture."

Hayworth takes this theory a few steps further. He looks at the growth of connectomics—especially advances in brain preservation, tissue imaging, and computer simulations of neural networks—and sees something else: a cure for death. In a new paper in the International Journal of Machine Consciousness, he argues that mind uploading is an "enormous engineering challenge" but one that can be accomplished without "radically new science and technologies."

...A piece of human brain tissue the size of a thimble contains around 50 million neurons and close to a trillion synapses. Scientists compare the task of tracing each connection to untangling a heaping plate of microscopically thin spaghetti....a human connectome would generate one trillion gigabytes of raw data. By comparison, the entire Human Genome Project requires only a few gigabytes. A human connectome would be the most complicated map the world has ever seen.

... _Chronicle

Here is how Hayworth plans to achieve his astounding miracle: Using an "ultramicrotome," he intends to have his brain fatally preserved in place while still alive, then "peeled" into ultra-thin slices, imaged in an electron microscope, and electronically "rebuilt" to a level of detail unimaginable with today's technology.

After Hayworth is placed under anesthesia, a cocktail of toxic chemicals will be perfused through his still-functioning vascular system, fixing every protein and lipid in his brain into place, preventing decay, and killing him instantly. Then he will be injected with heavy-metal staining solutions to make his cell membranes visible under a microscope. All of the water will then be drained from his brain and spinal cord, replaced by pure plastic resin. Every neuron and synapse in his central nervous system will be protected down to the nanometer level, Hayworth says, "the most perfectly preserved fossil imaginable."

His plastic-embedded brain will eventually be cut into strips, perhaps using a machine like the one he invented, and then imaged in an electron microscope. His physical brain will be destroyed, but in its place will be a precise map of his connectome. In 100 years or so, he says, scientists will be able to determine the function of each neuron and synapse and build a computer simulation of his mind. And because the plastination process will have preserved his spinal nerves, he's hopeful that his computer-generated mind can be connected to a robot body.

...Current methods of preserving brain tissue, an intensely fragile substance, top out at around one cubic millimeter—far, far short of an entire human brain. _Chronicle

So . . . . imagine that Hayworth succeeds in re-creating his brain's connectome within the programming of an infinitely fast super-computer. What will happen next?

When asked that question, most Al Fin cognitivists state that Hayworth is committing an error of logical levels. The mind is not, in fact, the connectome. Rather, the mind is the impossibly complex and dynamic -- never ending in life -- pattern of reacting, interacting, self-referential, and outwardly probing pulses and signals within the brain, which live within a physical and chemical environment of the body and the outer world, and which are constantly both enabled and limited by a unique pattern of genetic and epigenetic architecture and action.

Although still a young man, Hayworth is concerned about the possibility of his own death. He means to do something about it. His time and effort will not be wasted, entirely. He himself is unlikely to enjoy any sort of immortality which his current self would "enjoy." But his work will be used by others within a wider view of the mind and self. Reproducing a brain's connectome is likely to be one important piece of simulating that unique brain. But probably not the most important piece. And possibly not even a necessary piece.

I would like to see the techniques used on simpler brains, of course, before anyone considers using them on human brains. Worms and insects suggest themselves as excellent starting points.

h/t Brian Wang

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“During times of universal deceit, telling the truth becomes a revolutionary act” _George Orwell

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