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/

Shawn Mikula here. Allow me to clear up the confusion that appears to have been caused by being quoted out of context. I clearly state in the part of my answer preceding the quoted text the following:

"2) assuming you can run accurate simulations of the mind based on these structural maps, are they conscious?".

So this is not a question of misunderstanding universal computation and whether a computer simulation can mimic, for practical purposes, the computations of the brain. I am already assuming the computer simulation is mimicking the brain's activity and computations. My point is that a computer works very differently from a brain which is evident in differences in its underlying causal structure. In other words, the coordinated activity of the binary logic gates underlying the computer running the simulation has a vastly different causal structure than the coordinated activity and massive parallelism of neurons in a brain.

The confusion appears to result from the fact that I'm not talking about the pseudo-causal structure of the modeling units comprising the simulation, but rather the causal structure of the underlying physical basis of the computer running the simulation.

Anyway, I hope this helps.

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 corr... (read more)

1V_V11y

The natural objection is, why would the physical substrate matter? Let's assume you replace somebody's brain with a Von Neumann computer running a simulation of that person's brain. You get something that behaves like a conscious person, and even claims to be conscious person if asked. Would you say that this thing is not conscious? If you think it is not conscious, then what does "conscious" actually mean in epistemic terms? If I tell you that X is conscious, how do you update your posterior beliefs on the outcomes of future observations about X?

1jacob_cannell11y

Shawn - firstly, congratulations on your BROPA research and publication; it is likely to have high future impact. [...] Universal computation necessarily implies/requires multiple realizability of causal systems and thus functionalism. Part of the confusion stems from the use of the term 'consciousness' and all of it's associated baggage. So let us taboo the word and use self-awareness instead. Self-awareness conveys most of the same meaning, but without the connotations (just as we may prefer the term 'mind' over 'soul'). Self-awareness is a specific key information processing capability that some intelligent systems/agents possess. Some animals (dolphins, monkeys, humans, etc) demonstrate general self-awareness through their ability to recognize themselves in mirrors. Self-recognition in a mirror test requires a specific ability to construct a predictive model of one's self as an object embedded in the world. The other day while on a walk I came upon a songbird that was repeatedly attacking a car (with a short hop ramming maneuver). I was puzzled until I realized that the bird was specifically attacking the side view mirror. I watched it for about 10 minutes and it just did the same attack over and over again. The next day I saw it attacking a different car in about the same location. Humans possess a more advanced form of self-awareness related to our ability to use language to communicate. Natural linguistic communication is very complex - it requires a sophisticated capability to model not only one's self - but other self-aware agents as well, along with those other agent's models of oneself and other agents, and so on recursively. Self-awareness isn't a binary concept - obviously it comes in many varieties and flavours, such that individual humans are not self-aware in exactly the same way. Nonetheless, these differences are tiny in comparison to those that separate typical human self-awareness from feline SA or the rudimentary SA of current artificial

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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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