Putting Substance Dualism’s Money on the Table

Brains and digital computers go about computation in very different ways—so different, in fact, that it’s less than clear to me that “computation” (in the Turing machine sense) is what brains are really doing. This probably accounts for why trivial brain tasks like detecting speech, understanding natural language, and recognizing faces are at present next to impossible to do well in software, as anyone who has tried to use their mobile phone’s voice activated dialing can attest.

Researchers at Stanford are onto this:

Now Kwabena Boahen, a neuroengineer at Stanford University, is planning the most ambitious neuromorphic project to date: creating a silicon model of the cortex. The first-generation design will be composed of a circuit board with 16 chips, each containing a 256-by-256 array of silicon neurons. Groups of neurons can be set to have different electrical properties, mimicking different types of cells in the cortex. Engineers can also program specific connections between the cells to model the architecture in different parts of the cortex.

Substance dualists should be happy about this kind of research for two reasons. First, if it works, it is likely to yield new tools of heretofore unheard-of levels of aweXomeness. For instance, right now Google image search offers up pictures of trees based on the close association of a web image with text that talks about generally arboreal things. With massively scalable brain-like image recognition, maybe we’ll be able to do web-scale searches for pictures of, say, tire swings with foreboding skies in the background. But then physicalists get jazzed about this kind of thing too.

The real payoff for substance dualists is in the utterly faithful simulation of the human brain. That this will be done someday is a certainty. And theories of quantum consciousness notwithstanding, the brain is a machine—an elaborate configuration of matter scrupulously obeying the laws of physics. If substance dualism is true, then the silicon brain should be qualitatively different from the human one. It might be able to associate visual images with one another, find subtle patterns in search spaces, and carry on a spoken conversation with a person, but we would predict that its soulless-ness will in some way be obvious. Kind of like when Dr. Kurnow asked SAL in 2010 how she felt about being powered down: the question made no sense to her. Enfleshed souls tend to be a bit touchier about that one.

I have long thought it a key aspect of the Classical school that we always have our apologetic money on the table. Hence if the brain is the organ of the mind, then as technology allows, let’s build a replica brain and have a talk with it. If it’s indistinguishable from a person, I lose a line of evidence. If, the better and better we get at making silicon brains, the more and more obvious it is that these things are not human, then we need to have a nice, long talk about just how silly it is for me to believe that I have an immaterial component that is essential to my identity.

The metaphysics of the human person notwithstanding, it just wouldn’t fun if they didn’t create some nice, new bioethical dilemmas while they were at it:

Engineers ultimately hope to use the information generated by the silicon cortex in a variety of ways–to build better neural prosthesis, for example. “The real-time aspect of this technology allows us in principle to interface the silicon cortex with the real cortex or brain,” says Gert Cauwenberghs, a neuroengineer at the University of California, San Diego. “There is the promise, at least in the future, to build a prosthesis to replace some lost motor function or sensory function.”

And I’m sure it will stop there. William Gibson, call your office.

h/t Slashdot