Saturday, 2 June 2018

The Ethics of Exponential Life Extension through Brain Preservation

Chemical brain preservation allows the brain to be preserved for millennia. In the coming decades, the information in a chemically preserved brain may be able to be decoded and emulated in a computer. I first examine the history of brain preservation and recent advances that indicate this may soon be a real possibility. I then argue that chemical brain preservation should be viewed as a life-saving medical procedure. Any technology that significantly extends the human life span faces many potential criticisms. However, standard medical ethics entails that individuals should have the autonomy to choose chemical brain preservation. Only if the harm to society caused by brain preservation and future emulation greatly outweighed any potential benefit would it be ethically acceptable to refuse individuals this medical intervention. Since no such harm exists, it is ethical for individuals to choose chemical brain preservation.


CERULLO, Michael A. The ethics of exponential life extension through brain preservation. Journal of Evolution and Technology, 2016, vol. 26, no 1, p. 94--105.
  

Thursday, 31 May 2018

The Fallacy of Favoring Gradual Replacement Mind Uploading Over Scan-and-Copy

Mind uploading speculation and debate often concludes that a procedure described as gradual inplace replacement preserves personal identity while a procedure described as destructive scan-and-copy produces some other identity in the target substrate such that personal identity is lost
along with the biological brain. This paper demonstrates a chain of reasoning that establishes metaphysical equivalence between these two methods in terms of preserving personal identity.


WILEY, Keith B. and KOENE, Randal A. The Fallacy of Favoring Gradual Replacement Mind Uploading Over Scan-and-Copy. arXiv preprint arXiv:1504.06320, 2015.

  

Wednesday, 30 May 2018

Personal Identity and Uploading

Objections to uploading may be parsed into substrate issues, dealing with the computer platform of upload and personal identity. This paper argues that the personal identity issues of uploading are no more or less challenging than those of bodily transfer often discussed in the philosophical literature. It is argued that what is important in personal identity involves both token and type identity. While uploading does not preserve token identity, it does save type identity; and even qua token, one may have good reason to think that the preservation of the type is worth the cost.


WALKER, Mark. Personal identity and uploading. Journal of Evolution and Technology, 2011, vol. 22, no 1, p. 37--51.
  

Tuesday, 22 May 2018

Do Thin Spines Learn to be Mushroom Spines that Remember?

Dendritic spines are the primary site of excitatory input on most principal neurons. Long-lasting changes in synaptic activity are accompanied by alterations in spine shape, size and number. The responsiveness of thin spines to increases and decreases in synaptic activity has led to the suggestion that they are `learning spines', whereas the stability of mushroom spines suggests that they are `memory spines'. Synaptic enhancement leads to an enlargement of thin spines into mushroom spines and the mobilization of subcellular resources to potentiated synapses. Thin spines also concentrate biochemical signals such as Ca^2+, providing the synaptic specificity required for learning. Determining the mechanisms that regulate spine morphology is essential for understanding the cellular changes that underlie learning and memory.



BOURNE, Jennifer and HARRIS, Kristen M. Do thin spines learn to be mushroom spines that remember?. Current opinion in neurobiology, 2007, vol. 17, no 3, p. 381--386.

Monday, 21 May 2018

Memory Systems of the Brain

The idea that memory is composed of distinct systems has a long history but became a topic of experimental inquiry only after the middle of the 20th century. Beginning about 1980, evidence from normal subjects, amnesic patients, and experimental animals converged on the view that a fundamental distinction could be drawn between a kind of memory that is accessible to conscious recollection and another kind that is not. Subsequent work shifted thinking beyond dichotomies to a view, grounded in biology, that memory is composed of multiple separate systems supported, for example, by the hippocampus and related structures, the amygdala, the neostriatum, and the cerebellum. This article traces the development of these ideas and provides a current perspective on
how these brain systems operate to support behavior.



SQUIRE, Larry R. Memory systems of the brain: a brief history and current perspective. Neurobiology of learning and memory, 2004, vol. 82, no 3, p. 171--177.
  
  

Saturday, 19 May 2018

How would brain preservation work in practice?


Vitrifying the Connectomic Self: A case for developing Aldehyde Stabilized Cryopreservation into a medical procedure

... [b]ut the main point of this paper is to persuade the scientific and medical community
that now is the time to develop this ASC procedure into a reliable medical procedure that can be offered to terminal patients. This is a radical proposal that can easily be misunderstood. This misunderstanding often manifests itself in questions like: ``Why on earth would a terminal patient desire such an option in the first place?'', ``How would such a procedure work on a practical level?'', ``Are patient safeguards even possible for a procedure whose final success won't be known for decades or centuries?'', ``Can we even imagine the technologies that would allow future revival?'' 

Perhaps the best way to answer all of these questions is to offer a speculative short story meant to summarize and clarify this vision. The following fictional story follows a man diagnosed with Alzheimer's dementia in the year 2030 who chooses to undergo ASC preservation in the hopes of future revival. Extensive footnotes throughout this fictional story briefly explain the science behind key steps and point to references that support the science and technology discussed.



HAYWORTH, Kenneth. Vitrifying the Connectomic Self: A case for developing Aldehyde Stabilized Cryopreservation into a medical procedure.


Monday, 14 May 2018

Electron Imaging Technology for Whole Brain Neural Circuit Mapping

The goal of uploading a human mind into a computer is far beyond today's technology. But
exactly how far? Here I review our best cognitive and neuroscience model of the mind and show
that it is well suited to provide a framework to answer this question. The model suggests that our
unique ``software'' is mainly digital in nature and is stored redundantly in the brain's synaptic
connectivity matrix (i.e., our Connectome) in a way that should allow a copy to be successfully
simulated. I review the resolution necessary for extracting this Connectome and conclude that
today's FIBSEM technique already meets this requirement. I then sketch out a process capable
of reducing a chemically-fixed, plastic-embedded brain into a set of tapes containing
20x20 micron tissue pillars optimally sized for automated FIBSEM imaging, and show how
these tapes could be distributed among a large number of imaging machines to accomplish the
task of extracting a Connectome. The scale of such an endeavor makes it impractical, but a
version of this scheme utilizing a reduced number of imaging machines would allow for the
creation of a ``Connectome Observatory''---an important tool for neuroscience and a key
milestone for mind uploading.




HAYWORTH, Kenneth J. Electron imaging technology for whole brain neural circuit mapping. International Journal of Machine Consciousness, 2012, vol. 4, no. 1, p. 87--108.