On 2/22/07, Mark Peaty <[EMAIL PROTECTED]> wrote:

>
> Stathis:
>
> > "Stathis [from the other posting again]: 'There is good reason to
> > believe that the third person observable behaviour of the brain can be
> > emulated, because the brain is just chemical reactions and chemistry is a
> > well-understood field.'
> >
> > MP: Once again it depends what you mean. Does 'Third person observable
> > behaviour of the brain' include EEG recordings and the output of MRI
> > imaging? Or do you mean just the movements of muscles which is the main
> > indicator of brain activity? If the former then I think that would be very
> > hard, perhaps impossible; if the latter however, that just might be
> > achievable.
> >
>
> Huh? I think it would be a relatively trivial matter to emulate MRI and
> EEG data, certainly compared to emulating behaviour as evidenced by muscle
> activity (complex, intelligent behaviour such as doing science or writing
> novels is after all just muscle activity, which is just chemical reactions
> in the muscles triggered by chemical reactions in the brain). "
>
> MP: 'relatively trivial'? I think perhaps you underestimate what it
> involved; '... the brain is just chemical reactions, and chemistry is a
> well-understood field' reinforces this view. My point is that it is NOT just
> chemical reactions, but chemical reactions which take place in embodiment of
> multiple overlapping, inter-penetrating and self-organising hierarchies of
> dynamic structures. I think that various avenues of research are showing
> that a key feature of brain functioning which 'binds' together the 'just
> chemical' activities of multiple brain regions at any given moment and
> simultaneously at multiple scales of size, intensity and frequencies, is the
> harmonic resonance and interference patterns generated by wave forms which
> are made up of the combined actions of billions of neurons propagating
> thousands of impulses per second to form dynamic interaction patterns.
>

How could it not be chemical reactions? The fact that they are large and
complex macromolecules with some very complex physical chemistry involved
does not mean it's not chemistry, and neither does the fact that it is
easier to look at the emergent behaviour of the brain as a whole. If all the
relevant chemical reactions occur in the right order and the right
configuration, that is necessary and sufficient for a functioning brain.

I think the only way to truly grasp the scope of what is occurring is
> through visual imagination but linking one's ideas also to the experience of
> musical polyphony and rhythms. The trick is to 'see' in the mind's eye that
> the *effective* structures which make things happen and which constitute our
> experiences are in fact the wave patterns composed of swarms [or flocks,
> herds, shoals, clouds] of depolarisations. The neurons, ganglia, and
> whatever other 'physical' structural features you like to think about, are
> WHERE the dynamic interaction structures take place. Much work has been done
> to show that synapses vary in a metastable way in response to how they are
> used by the interaction patterns in which they participate, as also do
> dendrites which may move, extend, contract or die off in response to how
> they are used. The figurative nature of these patterns is embodied in the
> multiple, distributed locations in which most of their activity takes place
> and also in the characteristic temporal consistency of interaction between
> the spatially discrete or contiguous but contrastive locations. Furthermore
> it seems very likely, if not yet certain, that many synergistic effects will
> be occurring such as the occurrence of electric fields oscillating in
> directions orthogonal to the propagation of impulses.
>

Sure, but it's still just chemical reactions underlying all this.

MRI scans may be very good for pinpointing the topological features of this
> dynamic activity but not so the temporal details. On the other hand EEG
> records can give much better detail for some temporal features but the
> spatial resolution is very course and confined to areas near the skull. New
> techniques using laser beams passed through parts of the brain are capable
> of giving millisecond resolution to some events occurring deeper within. So
> also can very thin electrodes which report events within or near individual
> neurons, but here the problem is the limit to how many needles are allowed
> to be inserted into a human cortical pin cushion: not many! One day though
> someone is going to develop a kind of nanobot which can migrate
> unobtrusively through brain tissue and broadcast radio pulses describing the
> activity of neurons near by as well as key features of electric fields and
> other ambient conditions.
>

OK, but I thought you said that MRI and EEG data is difficult to emulate,
which it is not.

Stathis:'As for scientific research, I never managed to understand why Colin
> thought this was more than just a version of the Turing test. '
>
> MP: I think the key point is that successful basic science involves a
> degree of spontaneous creativity that is not merely an algorithmic
> implementation of rules, as opposed to, say, a competent chess-playing
> program or a merely classificatory program. It involves the construction of
> a new way of looking at the world, and then the testing of predictions which
> arise from the construct. In passing I would say this also is a key test for
> defining what is a REAL world. I tend to think that a Matrix of the
> eponymous Hollywood movie type, would suffer from being a Zenoverse: the
> resolution of time and space would be so lumpy as to REQUIRE a belief in a
> designer.
>

The idea of the Turing test is that "an algorithmic implementation of rules"
will give the required "degree of spontaneous creativity". If you don't
believe in this, then you don't even believe in weak AI, let alone strong AI
or computationalism. That is not a common position among scientists and
philosophers of mind; even John - anticomputationalism - Searle agrees that
the laws of physics necessitate that human-indistinguishable AI should be
theoretically possible. Roger Penrose, and Colin, are very much in the
minority.

Stathis: 'I can meaningfully talk about "seeing red" to a blind person who
> has no idea what the experience is like ... '
>
> MP: OK, but can he or she meaningfully understand you?
>

They can understand many things about sight without actually understanding
what it is like to have it, just as we can understand many things about a
bat's sonar, in many ways much more than the bat understands. But that part
of vision or bat sonar which cannot be understood unless the observer has it
himself, no matter how good the collected empirical data, is what is meant
by first person experience.

Stathis Papaioannou

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