Is it possible to upload our minds into a computer or in engineered living tissue?

[dyresand]

In recent times it has become appealing to believe that your dead brain might be preserved sufficiently by freezing so that some future civilization could bring your mind back to life. Assuming that no future scientists will reverse death, the hope is that they could analyze your brain’s structure and use this to recreate a functioning mind, whether in engineered living tissue or in a computer with a robotic body. By functioning, I mean thinking, feeling, talking, seeing, hearing, learning, remembering, acting. Your mind would wake up, much as it wakes up after a night’s sleep, with your own memories, feelings and patterns of thought, and continue on into the world.

We have often batted around this question here.  Not sure if anyone would like to have another go at it.  If so, this article by Kenneth D. Miller could provide a nice jumping off point for another go around.  Based on this article which appeared in last Sunday's NY Times which is all I know of the author, I believe he thinks it is not an in principle impossibility.  However he thinks it would be an enormously difficult problem requiring centuries of conceptual and technological breakthroughs.  In other words, we're skating on thin ice here since we must assume we will somehow answer questions we can't yet specify.  Yet he seems to be as much an expert as anyone we might like to find, and the article is pitched to our interested layman level.

Extended quote:

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I am a theoretical neuroscientist. I study models of brain circuits, precisely the sort of models that would be needed to try to reconstruct or emulate a functioning brain from a detailed knowledge of its structure. I don’t in principle see any reason that what I’ve described could not someday, in the very far future, be achieved (though it’s an active field of philosophical debate). But to accomplish this, these future scientists would need to know details of staggering complexity about the brain’s structure, details quite likely far beyond what any method today could preserve in a dead brain.

How much would we need to know to reconstruct a functioning brain? Let’s begin by defining some terms. Neurons are the cells in the brain that electrically carry information: Their electrical activity somehow amounts to your seeing, hearing, thinking, acting and all the rest. Each neuron sends a highly branched wire, or axon, out to connect or electrically “talk” to other neurons. The specialized connecting points between neurons are called synapses. Memories are commonly thought to be largely stored in the patterns of synaptic connections between neurons, which in turn shape the electrical activities of the neurons.

Much of the current hope of reconstructing a functioning brain rests on connectomics: the ambition to construct a complete wiring diagram, or “connectome,” of all the synaptic connections between neurons in the mammalian brain. Unfortunately connectomics, while an important part of basic research, falls far short of the goal of reconstructing a mind, in two ways. First, we are far from constructing a connectome. The current best achievement was determining the connections in a tiny piece of brain tissue containing 1,700 synapses; the human brain has more than a hundred billion times that number of synapses. While progress is swift, no one has any realistic estimate of how long it will take to arrive at brain-size connectomes. (My wild guess: centuries.)

Second, even if this goal were achieved, it would be only a first step toward the goal of describing the brain sufficiently to capture a mind, which would mean understanding the brain’s detailed electrical activity. If neuron A makes a synaptic connection onto neuron B, we would need to know the strength of the electrical signal in neuron B that would be caused by each electrical event from neuron A. The connectome might give an average strength for each connection, but the actual strength varies over time. Over short times (thousandths of a second to tens of seconds), the strength is changed, often sharply, by each signal that A sends. Over longer times (minutes to years), both the overall strength and the patterns of short-term changes can alter more permanently as part of learning. The details of these variations differ from synapse to synapse. To describe this complex transmission of information by a single fixed strength would be like describing air traffic using only the average number of flights between each pair of airports.

Underlying this complex behavior is a complex structure: Each synapse is an enormously complicated molecular machine, one of the most complicated known in biology, made up of over 1,000 different proteins with multiple copies of each. Why does a synapse need to be so complex? We don’t know all of the things that synapses do, but beyond dynamically changing their signal strengths, synapses may also need to control how changeable they are: Our best current theories of how we store new memories without overwriting old ones suggest that each synapse needs to continually reintegrate its past experience (the patterns of activity in neuron A and neuron B) to determine how fixed or changeable it will be in response to the next new experience. Take away this synapse-by-synapse malleability, current theory suggests, and either our memories would quickly disappear or we would have great difficulty forming new ones. Without being able to characterize how each synapse would respond in real time to new inputs and modify itself in response to them, we cannot reconstruct the dynamic, learning, changing entity that is the mind.

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http://www.nytimes.com/2015/10/11/opinio....html?_r=0

In short it is possible but the larger issue becomes is with ethics and technology and our knowledge we do not have a fully grasp  over 
sentience or fully understand the mind, one we finally really understand then we can and if we have the technology upload away.