RE: Computability of consciousness

Billy Brown (
Thu, 1 Apr 1999 10:12:43 -0600 wrote:
> Billy Brown, <>, writes:
> > In this sense you could view any complex object as encoding all sorts
> > of different programs, using many different schemes.
> So would you agree that my couch could be interpreted as having the same
> structure as any given program P?

Almost. It could be interpreted as containing any given program - but what you actually get is endless reams of random noise, with an occasional working program produced by chance. To create an exact equivalence between your couch and one particular program, you would have to use that program's code as your encoding scheme. In that case it would be more proper to say that the encoding scheme is equivalent to the program, and your couch is irrelevant.

> Perhaps even that the couch could be
> interpreted as encoding the same structure as a snapshot of Einstein's
> brain?

No. The effect you refer to relies on having such a vast amount of random data that the pattern you are looking for will occur somewhere just by chance. A couch has nowhere near enough states for this to work with something as complex as the brain. Actually, because of the combinatorial explosion involved, I'm not sure there is enough matter in the universe for such an equivalence to occur by chance.

> And that the reality and validity of this interpretation is as
> strong as viewing Einstein's brain as encoding that same structure?

No. It is equivalent to a tape backup of an uploaded version of Einstein - which brings up the whole identity problem again. That aside, however, I would say that there is an important difference between a computer that is running some arbitrary program, and a snapshot of the contents of that computer's memory at some instant. The snapshot does not contain all of the information in the original system, and it is not capable of displaying the same behaviors.

> Are you drawing a distinction between an encoding of a single state,
> versus an encoding of a sequence of states? You can see the couch
> encoding any given structure, but you can't see it encoding a specified
> sequence of complex structures (say, the sequence that a programmed
> computer or a brain goes through)?

A sequence of states is just a series of snapshots. What you are lacking is the process that created the changes between those states.

> Or is the issue here the fact that the sequence of structures are not
> "causally connected"? We can set up a mapping by which the couch goes
> through a sequence of states with the same structure as a sequence of
> states in Einstein's brain.

Well, no we can't. That is the problem. If we choose a scheme for mapping, say, thermal vibrations to neuron states, we might scan your couch and find an area where that is equivalent to the states in someone's brain at the same instant. However, if we scan the same area a millisecond later there will be no trace of that pattern. No matter how many times we repeat the experiment, we will never find anything but a momentary snapshot.

If you want to say that the two systems are equivalent, you have to be able to show that they display equivalent behaviors over time. Since the couch does not in fact think, or do any other kind of computation, no static coding scheme will be able to produce an equivalence.

> But perhaps we would say that the causal
> relationship of these states is not the same, because *if* we
> had tweaked
> some aspect of Einstein's brain state at a given moment, it would have
> led to changes in the pattern of succeeding states. But making the
> corresponding change to the state of the couch would not have led to
> the same kind of changes in the succeeding couch states..

Yes. Exactly.

Billy Brown, MCSE+I