Re: Brain on the Back of an Envelope

Anders Sandberg (
08 Dec 1997 20:42:08 +0100

Alex Tseng <> writes:

> How about organic interfaces e.g. processor drivers to nerve
> tissues ; neuro-chip replacement for spinal nerve connection
> etc etc ,... that's going to be a reality as well ...
> so that people like Christopher Reeves could possibly be walking
> again by 2027 or earlier , right ?

Hard to predict, but there is a lot of very promising work being done
right now. We are getting better and better at understanding cell
adhesion molecules, neurotrophic factors (which make axions grow in
certain directions) and growth factors that make neurons thrive. At
the same time there is plenty of work on neuron-chip interfaces,
ranging from letting them grow on field effect transistors to having
axons grow through holes in a silicon plate. The big problems to solve
are 1) how to make these systems last in the body (rejection, tissue
changes, neural wear and tear etc), 2) doing something useful with the
signals and 3) get some volume into the connections (there are
millions of axons in the spinal cord, and we need a sizeable fraction
(around 10% or so) in order to restore function).

My guess is indeed that by 2027 we should have the necessary know-how
to do it (or at least know why it can't be done if we are unlucky). Of
course, just because we can interface neurons with silicon doesn't
mean we will immediately get cool brain-computer interfaces, that is
much harder and is also influenced by trends in human-computer
interaction, competition with other systems such as wearable computers
and the big threshold of pain, expense, time and effort required to
get an interface to work for you.

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