Today, little robot rats — and tomorrow?

As sometimes happens, I find myself in an unplanned group of related posts. It may not be every article, but over a period of weeks a trend emerges.

The general subject this time is the nature of consciousness and human identity in the face of the growing evidence that the seemingly ineffable self-awareness we call “mind” is essentially a representation of our physical brain functions.

The particular stimulus today is an article by Linda Geddes in the September 27, 2011, issue of New Scientist. In “Rat cyborg gets digital cerebellum,” Geddes reports that a team at Tel Aviv University has implanted a “working” digital cerebellum into a lab rat.

This is a big deal for the rat, of course, but it’s potentially a far bigger deal for psychologists and philosophers trying to pin down the sources and — a much harder challenge — the nature of identity.

So far, the Tel Aviv team have managed only to replicate a single, simple reflex response; but they have high expectations of developing more sophisticated artificial brain parts, to say nothing of eventually implanting similar devices in human brains.

The first image that comes to mind is the scene in Frankenstein (1931), in which Dr. Frankenstein is informed by his colleague that the brain he has just inserted into his creature is “a criminal brain.” Dr. Frankenstein appears surprised for a moment, but then he replies that a brain is just a pile of tissue, and it doesn’t matter where it comes from.

That’s a complex claim, one that current research seems both to support and reject.  Our recent understanding strongly indicates that a brain is a brain is a brain, that we all share a single evolved anatomy. However, studies of brain injury patients and subjects with certain kinds of hereditary disorders just as clearly show that there are individual differences between brains, differences that cause sometimes dramatic differences in physical, emotional, and rational functioning.

There may be something equivalent to “a criminal brain” after all — and while it’s still sci-fi to imagine reforming criminals by replacing malfunctioning parts of their brains with digital parts, in much the same way that we now replace hip joints and heart valves, we’re getting closer every day to a time when the “-fi” will come off the “sci.”

What would that mean, philosophically? If my conscious mind is essentially a percept, a representation of the brain functions which produce it, how much difference does it make — if it makes any difference at all — that parts of that brain are made of polymer and not living cells?

Most people have no trouble accepting “Six Million Dollar Man” physical upgrades, like the texture-sensitive digital hand which helped a Paris lab monkey obtain a food reward — an accomplishment reported in the media yesterday.

But when it’s the brain, that’s another thing, isn’t it?

This is a terribly deep and complicated question, and I won’t presume to answer it, beyond the idea that the best answer likely will come from the fundamental understanding that while I am not my brain, I am entirely and only a product of my brain.

Of course, there are people who reject this notion, either partly or (less common) entirely. To these thinkers, the mind cannot be reduced to the brain. I agree, as I’ve written here frequently lately — the mind is not the brain; it’s a product of the brain. If the mind is an emergent property, in the way that table salt is not sodium and chlorine but another thing altogether that’s the result of a particular interaction of those two elements, that’s pretty much what I’ve been saying, isn’t it?

And if the mind is not a product of the brain because the brain is physical and the mind is not, I don’t see any way out of the dualistic corner into which that claim paints your argument.

Table salt is not sodium or chlorine; it’s not sodium and chlorine; it’s a product of an interaction between sodium and chlorine. But no one claims that table salt is therefore not something entirely physical.

And, for the same reasons, no one can claim convincingly that the mind is something not entirely physical.

So, let’s bring on the polymer parts, and senior moments, see you later!