Shawn Mikula on Brain Preservation Protocols and Extensions

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Recently published article in Nature Methods on a new protocol for preserving mouse brains that allows the neurons to be traced across the entire brain, something that wasn't possible before. This is exciting because in as little as 3 years, the method could be extended to larger mammals (like humans), and pave the way for better neuroscience or even brain uploads. From the abstract:

Here we describe a preparation, BROPA (brain-wide reduced-osmium staining with pyrogallol-mediated amplification), that results in the preservation and staining of ultrastructural details throughout the brain at a resolution necessary for tracing neuronal processes and identifying synaptic contacts between them. Using serial block-face electron microscopy (SBEM), we tested human annotator ability to follow neural ‘wires’ reliably and over long distances as well as the ability to detect synaptic contacts. Our results suggest that the BROPA method can produce a preparation suitable for the reconstruction of neural circuits spanning an entire mouse brain

http://blog.brainpreservation.org/2015/04/27/shawn-mikula-on-brain-preservation-protocols/

Here we describe a preparation, BROPA (brain-wide reduced-osmium staining with pyrogallol-mediated amplification), that results in the preservation and staining of ultrastructural details throughout the brain at a resolution necessary for tracing neuronal processes and identifying synaptic contacts between them. Using serial block-face electron microscopy (SBEM), we tested human annotator ability to follow neural ‘wires’ reliably and over long distances as well as the ability to detect synaptic contacts. Our results suggest that the BROPA method can produce a preparation suitable for the reconstruction of neural circuits spanning an entire mouse brain

http://blog.brainpreservation.org/2015/04/27/shawn-mikula-on-brain-preservation-protocols/

Thanks for replying ! Sorry if the bit I quoted was too short and over-simplified.

That does clarify things, although I'm having difficulty understanding what you mean by the phrase "causal structure". I take it you do not mean the physical shape or substance, because you say that a different computer architecture could potentially have the right causal structure.

And I take it you don't mean the cause and effect relationship between parts of the computer that are representing parts of the brain, because I think that can be put into one-to-one correspondence with the cause and effect relationship of the things being represented.

For example, If neuron N1 causes changes to neurons N2, N3 and N4; and I have a simulated S1 causing changes to simulated S2, S3 and S4, then that simulated cause and effect happens by honest-to-god physical cause and effect: voltage levels in the memory gates representing S1 propagate through the architecture to the gates representing S2, S3, S4 causing them to change.

Using a different computer architecture may avert this problem ...

So consciousness would have to then be something that flesh brains and "correctly causally structured" computer hardware have in common, but which is not shared by a simulation of either of those things running on a conventional computer ?

Thanks for the replies. I will try to answer and expand on the points raised. There are a number of reductio ad absurdums that dissuade me from machine functionalism, including Ned Block's China brain and also the idea that a Turing machine running a human brain simulation would possess human consciousness. Let me try to take the absurdity to the next level with the following example:

Does an animated GIF possess human consciousness?

Imagine we record the activity of every neuron in a human brain at every millisecond; at each millisecond, we record whether ... (read more)

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Shawn Mikula on Brain Preservation Protocols and Extensions

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Shawn Mikula on Brain Preservation Protocols and Extensions

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