"Can't the current brain/mind dualism, rather than being a sophisticated reflection of Cartesian duality, be more simply explained as a reflection of the current state of technology?"

Hmm, I was talking about the specific brain-is-a-computer metaphor, not the more general concept of brain/mind dualism of which the literalist software/hardware camp, predominant within the brain = computer circle, partakes in its own way. If you mean to imply that there is just one current brain/mind dualism, the computer with software/hardware one, I'd have to disagree. There are resurgent forms of Cartesian-style dualism (The Thing That Will Not Die, I call it) which, while not necessarily making what Gilbert Ryle calls the "category mistake" - of imagining two different, parallel substances - are very much current, for instance the "mysterianism" of the philosopher Colin McGinn and others. (My reading homework this weekend is a piece of his.)

If you only meant "current" in the sense of "current among certain AI professionals", then fine... But of course they're not the only ones engaged in philosophy of mind, even within scientific circles. The Churchlands I'd count as within scientific circles. They are engaged with current computer science, cogsci and neurological research, and they stress the importance of being grounded in that (she coined the term "neurophilosophy", which may or may not add more understanding to the debate, but at least it underscores the groundedness lacking in much previous philosophy of mind), while at the same time disagreeing with those also within those circles who are literalist high-tech-metaphorists du jour. I'm not sure I agree or will agree with much of what they say, but my impression so far is that they're at least on the right track in questioning whether human cognition is analogous to *anything* else and stressing that we have to look at the one thing we can study - the brain - without jumping to false comparisons. We love to make analogies and create metaphors, and that's central to how we form concepts in language and how we construct language itself (see George Lakoff's work), but we lead ourselves astray as often as not.

Anyway, I wouldn't venture to make any broad statements about current brain/mind dualism in general, since there's potentially a variety of irreducibly different - non-equivalent - forms of dualism. (And I'm just beginning to explore what those might be, as a student of philosophy of mind.) Each has to be considered on the basis of its own set of premises.

So, I didn't mean to imply, and I don't think I stated, that the brain-as-just-like-a-computer (hardware running software, with all that implies) model is a *reflection* (or great-great-grandchild) of Cartesian substance dualism, only that it's a *replacement* which is just as problematic, just for different reasons.

My impression is that those who promote this particular computer metaphor, with a stark software/hardware divide, think of themselves as *opposed* to substance dualism, since software - or "bits" - isn't a "substance" on a par with (material) hardware - or "atoms" (if I may use the fave Silicon Valley facile distinction of bits vs. atoms. Software engineers and WIRED magazine lifetime-subscription acolytes of Nicholas Negroponte have been patting themselves on the back for that one for years now, but I question the scope of its usefulness. Yeah, yeah; there are bits and there are atoms. So what? What does that distinction really add to the discussion?) But being an alternative to one ancient (i.e., with roots in Plato's Idealism) and much-encrusted form of dualism doesn't necessarily make them any less dualist in their own way.

I'd say their metaphor rests on a different misconception altogether from Descartes' misconception. I'm still working out what exactly that misconception is. (So sue me... Skepticism at times has to take the form of intuition, a hunch that things, as presented by others, just aren't right - which motivates one to keep digging. A skeptical attitude can't always have its arguments fully formed at the outset.)

I think the scientific ideas of brain function go a lot further than a naieve model
of compoutation. The big difference, it seems to me is that every neuron intereacts with about 10,000
neighbors, where in most comouters there are only about 4. So that mental images, if
you want to think of them that way, achieve a level of (10000)^n connections at the level of
n near neighbors, which means that evem with the slowness of neural signals, the
speed of silicon is outweighed by the brain's connectivity.

As far as I know, only very small assamblages of neurons can be modelled by the biggest fastest silicon.
I think some folks at Santa Barbara were looking into computational models of neurons, but
I am on vacation from libraries and sources. And the parallel chem/hormonal system doesn't have much of
a computing analog...