[tim58]

The human brain processes ~40gigabits/second of information. Current direct brain interfaces are probably closer to 400bits/second Computer to Brain. I think it's very possible that we will hit wetware limitations for direct brain interfaces an order of magnitude or two less than ~40gigabits/seconds. With less information to process the digital worlds created by brain machine interfaces will be significantly less stimulating than the real world.

In conclusion I believe the real world will always feel more real, and be generally preferred because the digital world will provide less total information to our brains than digital worlds, even with brain machine interfaces.

Neal Stephenson's 2019 book "Fall; or, Dodge in Hell" describes a path forward to the mysterious and sexy place through upload. Upload removes the wetware limitations and provides the most likely candidate for a mysterious and sexy place.

[pharke]

I would argue that that number is a bit high for sense input. Figures I've seen are about 20x lower on the high end. The only time I've seen estimates as high as the one you gave are when they are considering the full field of vision for each eye and translating that directly to pixels assuming there is 100% fidelity. Human vision doesn't work that way, we dedicate far fewer neurons to our peripheral vision outside the fovea. You also have to remember that neurons transmit data at a much slower rate than electrical connections (100m/s vs 300,000km/s) so the path to building a better brain machine interfce is to have a large number of electrodes which seems to me a fairly straightforward problem to solve e.g. make them smaller and adding more of them. The other side of the coin is that we aren't aware of all of our sensory input all of the time so you can get away with only transmitting the important stuff which greatly reduces the bandwidth needed. Further out, there's likely some form of abstraction going on inside our brains and if we can communicate data on that level we'll likely need even less input to create a realistic experience.

As an aside, I don't think I'd opt for the type of uploading outlined in that novel considering it involves a posthumous destructive scan of the connectome. There wouldn't be any continuity so you'd probably just end up with a copy. The only type of uploading I could see working would be a Ship of Theseus approach where you gradually replace your biological neurons with artificial neurons and even that causes some hesitation.