Re: Human Cloning: The Trade-In Strategy

Anders Sandberg (
Mon, 24 Feb 1997 15:47:00 +0100 (MET)

On Mon, 24 Feb 1997 wrote:

> I wonder whether one part of the
> solution to the mapping problem might not lie in further devlopments in that
> technology. Rather than a simple surgical or biochemical procedure of
> connecting the neural pathways, perhaps each end of the connection could be
> terminated in a "smart junction box", where the mapping process is assisted
> with some sort of "external" or at least non-biological aid. Developing the
> new functional connections then might be a cooperative process of the
> "trade-in" body, the transplanted brain and some fairly sophisticated
> computer device. Any thoughts on the viability of this approach?

We need good neural interfaces, of course. The computational problem
seems to be solvable in principle, but we need plenty of computing power.
I would say this is a nanotech-level problem.

> Also, I wonder what the order of magnitude is that we're talking about here.
> I assume that much of the cranial nerve structure would be carried across
> from the "original", e.g. the entire occular system, including the eyes
> themselves, would be transplanted, rather than attempting a hook-up to the
> "trade-in's" eyes. This would be more difficult with the nerves that serve
> the mouth and tounge, etc, but might not be insurmountable. If this were
> possible, then the connections across the spinal column would then be the
> biggest challenge. How many nerves are we talking about at that juncture?

The relevant number is the number of axons in the nerves. We have 12 pairs
of brain nerves and the spinal cord to think about. I seem to recall on
the order of 1 million axons in the optic nerves, and as a guess around
the same in the spinal cord (these are just order-of-magnitude estimates).
The other brain nerves are almost all much smaller, let's say they have 1
million axons together. The we get around 3 million axons to deal with.

Anders Sandberg Towards Ascension!
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y