Mind uploading

Philosophical issues[edit]

The main philosophical problem faced by "mind uploading" or mind copying is the hard problem of consciousness: the difficulty of explaining how a physical entity such as a human can have qualia, phenomenal consciousness, or subjective experience.^[37] Many philosophical responses to the hard problem entail that mind uploading is fundamentally or practically impossible, while others are compatible with at least some formulations of mind uploading. Many proponents of mind uploading defend the possibility of mind uploading by recourse to physicalism, which includes the philosophical belief that consciousness is an emergent feature that arises from large neural network high-level patterns of organization, which could be realized in other processing devices. Mind uploading relies on the idea that the human mind (the "self" and the long-term memory) reduces to the current neural network paths and the weights of synapses in the brain. In contrast, many dualistic and idealistic accounts seek to avoid the hard problem of consciousness by explaining it in terms of immaterial (and presumably inaccessible) substances like soul, which would pose a fundamental or at least practical challenge to the feasibility of artificial consciousness in general.^[38]


Assuming physicalism is true, the mind can be defined as the information state of the brain, so it is immaterial only in the same sense as the information content of a data file, or the state of software residing in a computer's memory. In this case, data specifying the information state of the neural network could be captured and copied as a "computer file" from the brain and re-implemented into a different physical form.^[39] This is not to deny that minds are richly adapted to their substrates.^[40] An analogy to mind uploading is to copy the information state of a computer program from the memory of the computer on which it is executing to another computer and then continue its execution on the second computer. The second computer may perhaps have different hardware architecture, but it emulates the hardware of the first computer.


These philosophical issues have a long history. In 1775, Thomas Reid wrote: “I would be glad to know... whether when my brain has lost its original structure, and when some hundred years after the same materials are fabricated so curiously as to become an intelligent being, whether, I say that being will be me; or, if, two or three such beings should be formed out of my brain; whether they will all be me, and consequently one and the same intelligent being.”^[41] Although the name of the hard problem of consciousness was coined in 1994, debate surrounding the problem itself is ancient. Augustine of Hippo argued against physicalist "Academians" in the 5th century, writing that consciousness cannot be an illusion because only a conscious being can be deceived or experience an illusion.^[42] René Descartes, the founder of mind-body dualism, made a similar objection in the 17th century, coining the popular phrase "Je pense, donc je suis" ("I think, therefore I am").^[43] Although physicalism is known to have been proposed in ancient times, Thomas Huxley was among the first to describe mental experience as merely an epiphenomenon of interactions within the brain, having no causal power of its own and being entirely downstream from the brain's activity.^[44]


A considerable portion of transhumanists and singularitarians place great hope in the belief that they may become immortal, by creating one or many non-biological functional copies of their brains, thereby leaving their "biological shell". However, the philosopher and transhumanist Susan Schneider claims that at best, uploading would create a copy of the original person's mind.^[45] Schneider agrees that consciousness has a computational basis, but this does not mean we can upload and survive. According to her views, "uploading" would probably result in the death of the original person's brain, while only outside observers can maintain the illusion of the original person still being alive. For it is implausible to think that one's consciousness would leave one's brain and travel to a remote location; ordinary physical objects do not behave this way. Ordinary objects (rocks, tables, etc.) are not simultaneously here, and elsewhere. At best, a copy of the original mind is created.^[45] Neural correlates of consciousness, a sub-branch of neuroscience, states that consciousness may be thought of as a state-dependent property of some undefined complex, adaptive, and highly interconnected biological system.^[46]


Others have argued against such conclusions. For example, Buddhist transhumanist James Hughes has pointed out that this consideration only goes so far: if one believes the self is an illusion, worries about survival are not reasons to avoid uploading,^[47] and Keith Wiley has presented an argument wherein all resulting minds of an uploading procedure are granted equal primacy in their claim to the original identity, such that survival of the self is determined retroactively from a strictly subjective position.^[48][49] Some have also asserted that consciousness is a part of an extra-biological system that is yet to be discovered; therefore it cannot be fully understood under the present constraints of neurobiology. Without the transference of consciousness, true mind-upload or perpetual immortality cannot be practically achieved.^[50]


Another potential consequence of mind uploading is that the decision to "upload" may then create a mindless symbol manipulator instead of a conscious mind (see philosophical zombie).^[51][52] If a computer could process sensory inputs to generate the same outputs that a human mind does (speech, muscle movements, etc.) without necessarily having any experience of consciousness, then it may be impossible to determine whether the uploaded mind is truly conscious, and not merely an automaton that externally behaves the way a human would. Thought experiments like the Chinese room raise fundamental questions about mind uploading: If an upload displays behaviors that are highly indicative of consciousness, or even verbally insists that it is conscious, does that prove it is conscious?^[53] There might also be an absolute upper limit in processing speed, above which consciousness cannot be sustained. The subjectivity of consciousness precludes a definitive answer to this question.^[54] Numerous scientists, including Ray Kurzweil, believe that whether a separate entity is conscious is impossible to know with confidence, since consciousness is inherently subjective (see solipsism). Regardless, some scientists believe consciousness is the consequence of computational processes which are substrate-neutral. Still other scientists believe consciousness may emerge from some form of quantum computation that is dependent on the organic substrate (see quantum mind).^[55][56][57]


In light of uncertainty about whether mind uploads are conscious, Sandberg proposes a cautious approach:^[58]