X-Message-Number: 11644
Date: Fri, 30 Apr 1999 13:17:48
From: Damien Broderick <>
Subject: emulation is the sincerest form of simulation

Mike Perry wrote:

< A sufficiently lengthy computation by no more than a Turing machine
should be able to emulate, not just simulate, a person in full. Of course
this is just a thought experiment, not a proposal for a practical
implementation. To such a person, emulated rain would be just as wet as
"real" rain is to you or me. >

I've never grasped why people have any trouble with this
almost-self-evident truth.

It simply restates what we already know about flesh-and-blood people.
Perhaps the apparent problem arises because the assertion is too mildly put.

An emulation should be able to experience both algorithmically coded `rain'
and `real rain' detected via suitable sensors in the external world.  In
the limit of fidelity, the two inner states would presumably be

This says no more than its converse: we *already* experience only
`emulated' reality, since the external world is transduced into our mental
state space via mediating sensors, feature detectors, input reduction,
representations and encodings of various kinds.  Given suitable interface
devices, we could surely `experience' rain falling on our hands by piping
neural and neurohumoral inputs directly to the brain stem or even higher in
the brain.  But we needn't wait for future technology.

I assume that nobody here doubts the constructedness of experience, and
probably of `self' (that is, that nobody asserts we routinely utilise an
apodeictic access, independent of brain and other neural processing, to
some noumenal realm).  Dr V. S. Ramachandran's new book PHANTOMS IN THE
BRAIN provides a delightfully readable account of numerous hi-tech and
try-at-home investigations into the way the body/brain constructs its
on-going more-or-less continuous shadowplay from hints, templates, feedback.  

In one wonderfully simple demonstration, Ramachandran describes how you can
experience *as happening to self* a blow struck to someone else's hand, or
even to a bare table top.  (This kind of exteriorization of self-viewpoint
is a commonplace among VR users.) Having a sequence of patterned but
unpredictable scratches or impacts made by a friend's finger on the back of
your own hidden hand, while at some distance you watch the same motions
echoed exactly on another surface, causes your brain's rather simple-minded
interpretative modules to assume that `you' must extend out *there* - and
you *feel* the scratches or blows happening many feet away.

In other words, you are routinely `emulating' your own raw feels, once
regarded as primary and indefeasible.

Whether this procedure is instantiated on a protein brain or an array of
distributed neurodes seems to me to make no difference at all.  I draw the
line, however, at seeing the printed algorithmic description of Einstein's
brain as conscious, since it's not having any run-time. Implement it
suitably, though, and I reckon the old gentleman would be very pleased to
learn about the latest thinking on geons.

Damien Broderick

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11644