i) no-one has even the slightest clue about how you would access the "data" to be downloaded all in one go. Presumably you would have to grab it all in one go with all the interconnections, chemical signals, synaptic transmitters, correctly mapped out with corrent weighting, time dependancies etc. pretty much instantly

ii) If you could get it no-one knows what you would do with it to make a mind. Given that there are 10^11 neurones each with 10^4 synapses - each synapse is a complex analogue device (NOT BINARY) and the connections are probably all pretty critical (or at least its difficult to know which ones we can do without) -

iii) The computing power is *very* parallel and not necessarily 'digital' for the reasons above. Although you might be able to simulate a neurone on a digital computer you are not just going to need a G4 to do this for a whole brain (which may (or may not) be a Turing Machine)

iv) no-one has even the slightest clue about how you would put the data back into your head again given the way it is stored there.

Best
Kzin!

* there are some complications so we can discuss this further if there are any pedants out there

** we are talking about straight forward physic based stuff mainly e.g. reconstruction of stereo from both ears, depth perception from about 5 distinct cues like vergence, focus etc, similar stuff for touch smell etc.
1) No one had the slightest clue what a computer was 500 years ago.

2) Biological functionality is probably very inefficient, I think you can simplify, restructure, enhance it's functionality until you have your software/hardware brain, hardware would limit some kind of evolutionary process but is it going to be needless?

3) A simple turing machine? Maybe that's exactly what we are...

4)

Today we're looking into VR as source of entertainment, education, communication and so on. Today we think the ethical layout 500 years ago was absurd. What does that conclude?
It certainly is pointing toward Safe and Permanent Virtual Reality (which means each one of you will have a independent reality running, which means you can't hurt anybody else, and by keeping you locked inside there, you're going to born and die there or possibly never die either but live there until a meteor crashes into the planet or the sun swallows it. Both of those could be prevented too, the humanity ported over to a database on a spaceship and sent out from the galaxy ensuring safety...