Shawn Mikula on Brain Preservation Protocols and Extensions

oge

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/

Perhaps he doesn't really understand the implications of universal computability.

Or perhaps he's skeptical of the fidelity of that kind of model. Evolution famously abhors abstraction barriers.

Would you care to quantify your 'almost everyone' claim? Are there surveys, etc.?

To add my own highly anecdotal evidence: my experience is that most people with a background in computer science or physics have no active model of how consciousness maps to brains, but when prodded they indeed usually come up with some form of functionalism*.

My own position is that I'm highly confused by consciousness in general, but I'm leaning slightly towards substance dualism, I have a background in computer science.

*: Though note that quite a few of these people simultaneously believe that it is fundamentally impossible to do accurate natural language parsing with a turing machine, so their position might not be completely thought through.

12jacob_cannell11y

No - it's just an observation from my experience (CS degree in the 90's). Just to be clear, he is making a clear conceptual mistake that indicates he does not understand universal computability: [...] If there is some other weird computer architecture that can reproduce the causal structure of neural interactions in wetware, then a universal computer (such as a Von Neumann machine) can also reproduce the causal structure of neural interactions simply by simulating the weird computer. This really is theory of computation 101.

4Luke_A_Somers11y

The problem is, he just - JUST - got done saying that he's talking about the exact case where it turns out that the simulation's subject completely encompasses the source of consciousness. If that were his objection, it wouldn't matter if it was Von Neumann or not.