Causality and consciousness

From: <hal.domain.name.hidden>
Date: Fri, 15 Jan 1999 22:03:05 -0800

The all-universes model may provide some insight into causation and
consciousness.

Philosophers define causation in what seems at first to be a backwards
way. Rain causes the grass to grow; therefore, we might think to express
this as, if it doesn't rain, the grass won't grow.

But this does not work, because if it doesn't rain, we will water the
grass, and it will grow anyway.

Instead, they express the causality as, if the grass doesn't grow, it
didn't rain. This is similar to the "contrapositive" from symbolic
logic, where "a implies b" is equivalent to "not-b implies not-a".

Causation is seen to be an essentially counterfactual relationship (that
is, it deals with things which are contrary to actual facts). Especially
when we deal with actual events, we describe the causal relationship in
terms of "if one of the events didn't happen". But it did happen.

The status of counterfactuals is a problem in philosophy. Philosphers
invoke imaginary universes to describe them, but then how real can
causality be if it can only be described with reference to imaginary
situations?

However, in the context of the all-universe model, we have a ready set of
additional universes to work with, all as real as our own. This allows
counterfactuals to have a greater degree of reality. We can express
"if not-b then not-a" as "in all universes in which not-b occurs,
not-a occurs". It is a well defined set of relationships among the
contents of actually existing universes.

I got thinking about causality because some people suggest that it has
a crucial bearing in the phenomenon of consciousness. I first ran into
this, obliquely, in Searle's famous "Chinese Room" thought experiment.
This purports to be a philosophical demonstration that the computational
model of mind is absolutely wrong, that no computer could be conscious
merely by virtue of running the proper program.

Searle's Chinese Room is interesting for the wide variation in responses
it produces. Many people find it absolutely convincing, while others
see it as transparently absurd. A good discussion is in Hofstadter's
book Goedel, Escher, Bach.

If the computational activity of the brain isn't what produces
consciousness, what is? Searle points rather vaguely to the possibility
that the brain possesses "causal powers" which produce consciousness.
He never really defines what these causal powers are; they are really
just a placeholder for whatever the brain might be doing to produce
consciousness, since he feels he has shown that it can't be just its
information processing.

Searle's ideas aren't well regarded in the circles I frequent, but the
idea of causality playing a role in consciousness does come up. This
is an approach to the issue Wei raised: is it state, or information
processing that produces consciousness? Some people suggest that it
is information processing, and that specifically the processing must
have a causal flow.

It is not enough, in this view, to reproduce an instance of information
processing in a non-causal way. For example, we could monitor each
neuron in the brain and record its firing pattern, then play back those
patterns in another brain which has had its neural connections all
severed. Each neuron would have its own "recorded tape" for when it
was supposed to fire, based on the measurements made in the brain which
was thinking. In the playback brain, the neurons all fire with exactly
the same patterns as in the conscious brain. Is it conscious?

(My solution is, as I said earlier, that the question isn't meaningful,
because it is at best another iteration of an already-produced calculation,
and it doesn't matter if a conscious calculation is instantiated multiple
times.)

According to the consciousness-as-causality view, this playback is not
conscious, even though the patterns are all the same. There is no causal
relationship among the neural firings as their was in the real brain.
Without causality, there is no consciousness.

If we accept that consciousness is a real phenomenon deserving of
explanation, this view would require that causality is also a real,
fundamental, physical phenomenon. But if the only way causality can be
defined is as a relationship that spans multiple universes, it would
follow that consciousness also must fundamentally involve multiple
universes.

This is not necessarily as absurd as it may seem at first. Our
consciousness seems to inherently be an active process. The sense we
have of being conscious is intricately bound up with the sensation of
the passage of time. Yet time "passing" is really a matter of the
increase of entropy, which can also be related to universe splitting
in either a many-worlds or all-universes model. So it is already clear
that our perceptions do partake of some aspects of the multiple worlds.
If we could somehow bring counterfactuals into this, then we might be
closer to a coherent theory of consciousness.

Hal
Received on Fri Jan 15 1999 - 22:19:14 PST