PTN interviews D.J. MacLennan; futurist and author on the subject of cryonics

D.J. MacLennan is an author and futurist who had been researching the state of cryonics and cryopreservation for his book: Frozen to Life: A Personal Mortality Experiment. PlanetTech News interviews him about the current state of cryonics and how he sees the future of cryopreservation technology:
How did you come across the topic of cryonics and why did you decide to write a book about it?
I first heard about cryonics in a Scottish newspaper article about Alcor, around 2003. It piqued my interest, but I did not sign up as a member until several years later. I had been thinking about the brain and the parallels between its operation and the virtual machine concept in computing. I was reading Ray Kurzweil’s The Singularity is Near and K. Eric Drexler’s Engines of Creation. Kurzweil’s "patternist" approach to the subject of mind and the philosophical problems of personal identity fascinated me, and I began to think of the mind as a kind of emergent virtual machine supervening on the biological substrate of the brain. Through reading Drexler’s work on nanotech, I began to see how it might some day become possible to trace, infer and repair broken neuronal networks at the molecular level. Cryonics began to look like a reasonable proposition, so I signed up.
In 2010, I changed career direction. With more time to think, I found myself writing articles, mostly on neurophilosophy and futurism/transhumanism topics. But persistent questions from family, friends and acquaintances about my decision of a few years earlier to sign up for cryoperservation drove me in the direction of writing a book about it. Frozen to Life: A Personal Mortality Experiment was published in August of this year.
What have you discovered about the current state of cryonics through your research for the book? 
There are various different, sometimes conflicting, approaches to the gargantuan challenge of preserving brain structure at high fidelity. Not all of those approaches are connected directly to cryonics, but all have implications for the field.
The issue of head-only "neuropreservation" (the option I have chosen) is particularly contentious. Alcor offers the option, but the Cryonics Institute does not. The CI believes that neuropreservation is bad for the public image of cryonics, creating a perception that it is a gruesome "Frankenstein" science. As this isn’t a scientific objection, I reject it. What matters is to find the best, most efficient preservation method, regardless of public perception.
But we are also seeing consensus emerge in cryonics. The majority of cryonicists are science-informed reductionists, and we see much in current neuroscience research that is moving the debate in our direction. Dualism is dead. You are the emergent pattern we call "mind", and there is no extra "secret sauce" in the mix. Self, and even "free will", are useful cognitive illusions, with "conscious" decisions registering in the brain after actions have been taken. Cryonicists don’t tend to see a "hard problem of consciousness"; we see opportunities to make radical use of connectionist neuroscience to save irreplaceable patterns — persons — from destruction.
In summary, I think that the field of cryonics is currently in a state of steady innovation, development and healthy philosophical and scientific debate. It is a field ready to shed its maverick image and join the mainstream of scientific and public discourse.
What have been the biggest advances in the field of cryonics in the past 10 years?
Advances in vitrification techniques to preserve brains at very low temperatures with minimal formation of damaging ice crystals have been important. There are drawbacks to using very high concentrations of toxic cryoprotectant chemicals, but these are vastly outweighed by the dramatic retardation of ice formation resulting from "glass state" vitrification instead of freezing. Grey Fahy’s pioneering experiments with vitrifying rabbit kidneys (in M22 vitrification solution), and then transplanting them back into their original donor animals (with varying degrees of "life supporting function" observed) provided invaluable proof-of-concept for cryonicists.
Of course, we don’t remember with our kidneys. But Vita-More and Barranco’s recent vitrification and revival experiments with C. elegans worms indicate that memories can survive vitrification intact. 
Ken Hayworth’s aldehyde-stabilized cryopreservation (ASC) — a hybrid approach utilising elements of cryopreservation and plastination — is a fascinating new avenue in brain preservation.
And though not directly an advance in the field of cryonics, work on connectomics (mapping connectomes — the "wiring diagrams" of brains) has been a hugely important development. I agree with connectomics scientist Sebastian Seung that "We are our connectomes". Seung is sceptical about cryonics, but I think that detailed observation of widespread, neurite-level connectome integrity in vitrified brain tissue would force many of the sceptics to reconsider their views.
Do you think that initiatives such as “The Brain Preservation Prize” or “The Grand Challenges in Organ Preservation” are going to make big impact on progress in the field of cryonics?
It’s hard to say. But I’m a "thousand flowers" type of pragmatic optimist, so I’m happy to see many different initiatives of this kind blooming. And I find the diversity of aims of "The Brain Preservation Prize" laudable. Brain preservation is a crucial scientific endeavour in its own right; we must find ways to preserve brain networks at high resolution/fidelity. How will we ever learn how brains really work if we can’t preserve them well enough for long enough to study them properly?
The fields of cryonics and cryobiology are, of course, inextricably linked. All steps towards better organ preservation for transplant will have spin-offs for cryonics research, and (although cryobiologists may try to deny it) vice versa.
What are the biggest problems blocking progress from the state of the art now to reversible whole brain cryopreservation?
Attitudes. Backward, religionist, dualist beliefs and customs. Lack of funding. Fear of potential damage to their professional reputations prevents even some supportive neuroscientists from backing cryonics research publicly. Some cryogenicists and cryobiologists go to great pains to distance themselves from cryonics. With enough financial backing and more top-flight scientists involved in the effort, we could make much faster progress towards perfecting cryopreservation or chemo-cryopreservation techniques.
Reversibility, however, is another matter. Let’s say we find a method that shows demonstrable, high-fidelity preservation of neurites throughout an entire brain. How do we release that preserved connectomic ultrastructure from its fixative scaffold without damaging it? It’s hard to imagine that we could do that without the aid of nanomedicine, and to get there — to build the necessary recovery and repair nanomachines — we may need to perfect atomically precise manufacturing (APM). That will require a great deal more funding, research and a shift in focus away from vaguely-defined "nanotechnology" and towards the specific goal of engineering useful, self-assembling nanoscale machines from mechanically stiff, atomically precise components.
Why do you think the general public seems to have so little interest in cryonics?
I actually think that the general public is quietly fascinated by the subject. It might just be that cryonics (with its blurred life/death boundary connotations) is a shorthand abstraction (SHA) that is difficult to absorb and interrogate. By that, I mean that although interest is there, perhaps the questions that would generate a stimulating, vociferous public debate are not — yet. Therefore, public discourse on cryonics is sparse and stuttering, and the debate that does emerge is often sensationalist.
I think that one way into the "public consciousness" is through our personal stories. And that’s another reason why I wrote the book. We have to take cryonics out of the realm of science fiction and ground it in the nitty-gritty of real lives and, of course, real science.
But remember also that discussing cryonics means discussing death, sometimes in a pretty unsentimental way. Most people don’t want to talk about their own deaths. They wrap the subject in religion, custom, fatalism — anything to avoid genuine contemplation of its relentless approach. Most people don’t talk much about writing their wills either.
Where do you see cryonics in 10 and 20 years?- on what grounds do you make these predictions?
In 10 years time, I think we’ll be seeing much greater crossover between cryonics, cryogenics, cryobiology and connectomics. With connectomic mapping speeds growing exponentially, mapping ever greater volumes of brain tissue in ever greater detail, we may well have strong evidence indicating that cryonic vitrification (or a related technique) preserves brain ultrastructure intact. This evidence (and other evidence from experiments building upon those I have mentioned above) will lead reductionist scientists inexorably towards the conclusion that vitrification preserves the critical substrates upon which the emergent patterns of mind, memory and "personal identity" supervene.
Therapeutic hypothermia will become a widely-used surgical technique. In 10 years time, many surgeons will be testing its limits, operating at progressively lower temperatures for progressively longer periods of time. Already, we see therapeutic hypothermia (also known as targeted temperature management) used after cardiac arrest, in treatment of gunshot victims and in treatment of neonatal encephalopathy.
Within 20 years, we may see the beginnings of "deep sleep stasis" techniques for manned space voyages lasting many months. NASA’s Innovative Advanced Concepts programme is funding research into this.
Within 20 years, these and other biomedical developments (including longevity treatments) will bring about a change in attitudes towards death. It will become increasingly difficult to draw a clear line between life and death. Along with a rise in this more nuanced view will come a great upsurge in interest in cryonics, necessitating a big expansion in cryonics facilities worldwide.
As a writer, what other topics in the biomedical field you find fascinating that also make good material for a popular book?
I have some ideas on that front, but I’m not going to give them away right now! Suffice to say the we are really just at the beginning of an amazing journey of discovery about the human brain, and into what it actually means to be thinking/living/dying entities. Expect many popular science books to probe each new discovery from many angles. It’s going to be "neuro with everything".
And as we consider (then experiment with) ways to augment our bodies and brains, and even to extend our lives far into the future, we will increasingly question what it means to be human. It’s going to be fascinating, accelerating, radical and challenging. I’m not at all sure that popular science writers will be able to keep up!