[etrautmann]

As a neuroscientist working on brain computer interfaces, it's painfully clear to me that we are absolutely nowhere close to understanding the full complexity of the human brain in a manner required to simulate or reboot someone's consciousness. It's not even clear yet what level of abstraction is required. Do we need to map all of the synapses to get a connection graph, or do we need to map all synapses plus the synaptic proteins to assign connection weights too? This is ignoring other types of connections like gap junctions between cells, ephaptic coupling (the influence of local electric fields on neurons firing), mapping neuormodulator release, etc. On one hand, it feels like irreduceable complexity. On the other hand, however, you can lose about half of your neurons to neurodegenerative diseases before you start noticing a behavioral effect, so clearly not every single details is required to simulate your consciousness. It would be a MAJOR leap forward in neuroscience to even understand what level of abstraction is necessary and which biological details are essential vs. which can be summarized succinctly.

Anyone claiming to take your brain and slice it up and have a working model right now is currently selling snake oil. It's not impossible, but neuroscience has to progress a ways before this is a reasonable proposition. The alternative is to take the brain and preserve it, but even a frozen or perfused brain may have degraded in ways that would make it hard to recover important aspects that we don't yet understand.

It is, however, fascinating to do the research required to answer these questions, and that should be funded and continue, even if just to understand the underlying biology.

[radarsat1]

In addition to all that we don't know about synapses etc, I've often wondered if even mapping all the "hardware connections" so to speak would even be enough. You'd have everything in the right place, but what about the "signals" running on it? Does a certain amount of constant activity on these circuits constitute signs of a "living" brain vs a dead one? How much of our consciousness is really in the topology of the circuits, and how much of it is simply defined by the constant activity running around in them? I assume neural circuits form loops that consist of synapses that reinforce or surpress activity. If these signals going around and around ever "stop", can they ever be started again with the same "patterns"? What if these patterns, the living "software", are at least partially what define you?

Well anyway that's my airchair crackpot neuroscience theory for the world to consume ;). I'm sure there must already be a name for the idea though.

[ImPostingOnHN]

This article [0] may help here:

Six of the sheep were given a single higher dose of ketamine, 24mg/kg. This is at the high end of the anesthetic range. Initially, the same response was seen as with a lower dose. But within two minutes of administering the drug, the brain activity of five of these six sheep stopped completely, one of them for several minutes – a phenomenon that has never been seen before.

“This wasn’t just reduced brain activity. After the high dose of ketamine the brains of these sheep completely stopped. We’ve never seen that before,” said Morton. Although the anesthetized sheep looked as though they were asleep, their brains had switched off. “A few minutes later their brains were functioning normally again – it was as though they had just been switched off and on.”

0: https://www.technologynetworks.com/neuroscience/news/sedated...

[johnea]

Just to add a current link to this conversation:

https://www.scientificamerican.com/article/consciousness-mig...

An article suggesting that consciousness is embodied in the active fields, not the synapses themselves.

[alchemist1e9]

Losing half neurons caught my attention. I believe we had a post about how LLM weights being trimmed by 1/2 still had them functional. Interesting.

[idreyn]

On one hand, I wonder if a gradual transition would work. Spend enough time over the years mirroring your conscious patterns onto a computational substrate, and they might get used to the lay of the land, the loss of old senses and the appearance of new ones. There might not be an ultimate "stepping in", but something like you might be able to outlive you, on a substrate that it feels happy and comfortable on.

On the other hand, the idea of "simulating your consciousness" raises questions beyond just cognition or personality. A mechanistically perfect simulation of your brain might not be conscious at all. Spooky stuff.

[belfalas]

Keying off your comment - in the field of neuroscience, is consciousness viewed as a kind of simulation?

(I'm just a programmer so it's fascinating to me to consider how actual brain scientists model consciousness in their work.)

[suzzer99]

Imagine the bugs introduced in trying to make a digital copy of a brain. Terrifying for the subject.

[scotty79]

There's gonna be million artificial minds of various levels of capacity before the first human mind is accurately simulated.

At that time we are going to be accustomed to glitching artificial minds creates, modified, bugged, debugged that current moral conundrums "is the copy me or not", "is it ok to create a hobbled copy of someone" are going to be as quaint bit akin to counting angels on a head of the pin. Mangled and molded consciousness will be as mundane as computation itself.