Mind Uploading

An Argument for the Scientific and Technical Plausibility of Preserving Thoughts Indefinitely

BY KENNETH HAYWORTH

PETER KASSAN’S ARTICLE IN THIS ISSUE OF SKEPTIC argues that the idea of mind uploading is “science fantasy, based on a misunderstanding both of the overwhelming complexity (and our near-total ignorance) of the brain, and of what computer models are.” Do any real neuroscientists believe that mind uploading might be possible? Kassan’s article mentions one that does—me. So I have been given the honor to write this rebuttal.

Any discussion regarding mind uploading must be about what can reasonably be assumed possible in the distant future, not what is achievable today. I am certainly not arguing uploading will be easy, or that it will occur within the next few decades; but I will argue it is a technically achievable, potentially desirable, long-term goal. I will present evidence that current neuroscience models support the possibility. I will cover recent developments in electron microscopy that hint at the technology needed. I will touch on cognitive models that directly support the mind-as-computation hypothesis, and I will delve deep into the consciousness debate. Finally, I will discuss a recently developed method for long-term brain preservation that seems sufficient to support future mind uploading, a fact that makes this discussion not merely academic.

Possible vs. Impossible

Hopefully we can all agree that it is physically possible to one day colonize the planet Mars with vibrant, self-sustaining encapsulated cities. And we can also all agree that such colonization would be incredibly difficult, requiring enormous resources and advancements. If colonization were ever to occur it is reasonable to assume it would take centuries. Reasonable people can disagree on whether Mars colonization is even a desirable long-term goal. They can also disagree on whether the first small self-sustaining colony will be achieved by the year 2050, 2150, or 3050. And they can certainly disagree on how best to prioritize today’s resources with respect to that goal. But it would be unreasonable to level unsupported statements that such colonization is physically impossible, especially in the light of our successful baby steps toward that goal (e.g., landing men briefly on our moon). And it would certainly be unreasonable to ridicule the scientists and engineers (e.g., those at NASA and SpaceX) who, motivated by such lofty long-term goals, have decided to devote their lives to tackling some of the technical obstacles.

Kassan’s argument is analogously structured, asserting that mind uploading is theoretically impossible but backing up his assertion only by pointing out its great technical challenge. His argument ignores the significant “baby steps” that have already been taken (e.g., automated, reliable methods that scan neural tissue at the nanometer scale). Further it ignores the fact that all of today’s neuroscience models are fundamentally computational in nature, supporting the theoretical possibility of mind uploading. Kassan declares “our near-total ignorance of the brain,” a quite inflammatory statement that I find perplexing given neuroscience’s enormous advances just in the past decade. A small counter example: a flurry of papers have recently tested decades old computational models of how memories are formed by genetically tagging (in mice) only those neurons active during a fear memory formation. Optogenetic reactivation of those same “engram” cells was sufficient to recall the memory,1 and to “incept” a false memory,2 and have confirmed long-suspected aspects of the synaptic connectivity underlying memories.3

Is it Possible to Image Synaptic Connectivity?

Kassan’s article points out the obvious: our current technology is not sufficient to scan an entire brain at the required resolution. This is equivalent to arguing that Mars colonization is forever impossible because we don’t currently have the rockets. Kassan actually goes so far as to claim something as “impossible” that I and other scientists have been doing on a small scale for years. He states: “A proposed (but never implemented) method of gathering the information involves preserving your brain in some kind of plastic and then sectioning it… This is unlikely to work. However thin each slice is, it would be impossible to section your brain without destroying a countless number of synapses.”

“Impossible” is a strong word. Since 1958 electron microscopists have been embedding brain tissue, sectioning and imaging it to create 3D models of every synapse.4 Recently 3D electron microscopy (3DEM) has undergone a revolution.5 It is no longer necessary to collect fragile sections, instead a technique called Serial Block Face Scanning EM is much more reliable and automated.6 The surface of a plastic-embedded sample is imaged with a scanning electron microscope (SEM), then a 25nm layer is automatically scraped off with a diamond knife, and the fresh surface is again imaged. Repeating this cycle thousands of times creates 3D images of neural circuits.7,8