[david-given]

I doubt the scans really high enough resolution for a meaningful simulation --- I don't believe MRI scans can capture the complete connectome of a single human brain, let alone any subcellular data.

e.g. the Human Connectome Project is still working on capturing the macroscale connectome, that is, high level structures only. Recording the microscale connectome, that is, the neuronal structure, currently requires destroying the brain you're analysing.

[marmaduke]

As the research engineer on the Virtual Brain simulator to which I linked, which we apply to improve e.g. epilepsy diagnosis, I can say that those scans do have enough resolution to capture global properties of anatomy and dynamics of brain networks.

[david-given]

Yes, but that's just large scale structures. This wouldn't be simulating any of the features which most people find interesting about brains, i.e. the personality. It's important to make that clear. This is not a brain upload.

[marmaduke]

Personality would be expressed as interperson variability in certain parameters or connectivity of the brain model. It's not at all mystical or hiding in the subcellular structure.

Brain upload is a sci-fi invention; using a T1, DWI, fMRI, EEG and behavioral data to build a realistic model of a subject's brain is today's neuroscience.

[jpellman]

Brain upload is a sci-fi invention; using a T1, DWI, fMRI, EEG and behavioral data to build a realistic model of a subject's brain is today's neuroscience.

I will echo this point. I don't think I've met anyone in the field of neuroimaging who sees mind uploading as plausible. There's simply too much noise in the data for that sort of thing. Even simplified simulations such as the Human Brain Project require so much computing power that modeling a single mind is prohibitive; I can't imagine trying to perform whole-brain emulation accurately and practically without incurring more cost than it's worth. Wetware is good enough for me.

[marmaduke]

> (1) Even simplified simulations such as the Human Brain Project require so much computing power that (2) modeling a single mind is prohibitive

This step from (1) to (2) is a common assumption that most people are unwilling to reconsider, but it's equally possible to reject bottom-up modeling and ask what are the high-level constraints on brain activity that shape and direct it. This is what we do with the data I mentioned (T1, EEG, etc).

[shpx]

You need at least 10 picometer percision to go down to the cell level (1.5L / 86 billion neurons), MRIs are 1mm according to the talk dcunit3d posted [0].

[0] https://www.youtube.com/watch?v=HdrSZtB0uX0

[amluto]

10 picoliter, perhaps? That's much less crazy than 10 picometer.

But you want the dendrites, too, not just cells.

[marmaduke]

Why would you want to simulate cells?