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View submission: Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
Neuroscientists (and science fiction writers I suppose), with advances towards extending the human life and the desire to essentially cheat death, how are we looking towards digitising the human brain?
Is it more viable to consider a Ship of Theseus style transition where a person's brain, consciousness and other factors are copied over slowly and gradually vs those instant scan and copy theories portrayed by science fiction?
Thinking that our current brain and selves are made of entirely new cells and existence from that of what we were originally born with, are we not essentially bio-organically copying a version of our previous selves in the same sort of way a slow and gradual digitisation might achieve?
Maybe this applies more for transference than copying?
Comment by aTacoParty at 18/01/2024 at 20:32 UTC
2 upvotes, 0 direct replies
One interesting fact is that our brain is not made of entirely new cells. Unlike most other organs in our body, brain cells are not dividing and the majority of the neurons in our head are present at birth. The connections between these cells are changing and the strength of these connections change as well.
But the ship of Theseus still applies here if we zoom in as the proteins, lipids, and carbohydrates that make up our neurons are constantly being turned over so even though the cells are always there, their components are being swapped out.
Theoretically if we could construct a human with all the same brain cells and all the same connections, they would have the same brain and supposedly same consciousness as you.
The issue of digitizing the brain/consciousness is that the brain is so incredibly complex that we can't accurately model it. Each neuron has about 1000-7000 connections to other neurons. Each of those connections can send different messages via neurotransmitters of which over 100 have been described with an even larger diversity of receptors. Add to the mix the glial contribution to synaptic transmission and it's a system too complex for us to properly model with current technology.
Currently we are working towards digitizing the nervous system of c elegans, a small worm commonly used in science. It has 302 neurons and about 15,000 connections. We've mapped all these neurons and all the connections and just recently have we been able to generate good computational models (see below).
I think that we will progress rather rapidly towards digitizing consciousness but we're still very far away from doing it properly. I've read that there are some companies that will create a large language model based on the texts/writings of specific people to mimic them. It's a far shot from consciousness but it's probably closer than we've ever been.
Synapses per neuron - https://www.sciencedirect.com/science/article/pii/S0531556502001511
Neurotransmitters - https://www.cell.com/fulltext/S0960-9822(05)00208-3
Glia and synaptic transmission - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8513541/
Computational model of c elegans - https://www.nature.com/articles/s41598-022-25421-w