Re: COMP/NEURO: Images Extracted from Cat Brain

Eliezer S. Yudkowsky (
Sat, 09 Oct 1999 20:33:01 -0500

> Such revolutionary devices should not be expected in the very near future.
> They will require decoding information from elsewhere in the brain looking
> at signals that are far more complicated than those decoded from the cat's
> thalamus but, in a way, the principle has been demonstrated.

All right. I wasn't going to take the time to write this up even briefly, since I didn't think it would be necessary, but perhaps I was wrong.

In order to build useful siliconeural interfaces, you need some idea of what the brain's internal coding system is. To build true telepathic interfaces, you need to decode high-level cognition and concepts, things that live in the prefrontal lobes of the cerebral cortex, not just relatively "easy" encodings like the visual cortex or the highly modular and localized emotions of the limbic system. I don't know what the high-level codes are, but I can tell you where to start looking.

Certain thoughts - certain complex intellectual structures, presumably distributed all over the frontal cortex - reliably create certain emotions. This is what I call a semantic binding, and it's an amazing thing, when you think about it. Imagine translating the thoughts into the kind of propositional-logic semantic networks LISP-based AIs use - like, "Bob broke my ribs" to "hurt(person72, me)"; which, in one of those AIs, really translates to "G023(G052, G187)".

(Yes, Eugene Leitl, I know the mind's not a semantic network; that is, in fact, exactly my point.)

How does the mind know to bind the thoughts to the emotion of anger? How can the limbic system reliably single out symbol G023? If you look at the modular and simpler limbic system, and look at the codes it uses to interface to high-level cognition, you'll find a set of regularities that exist reliably, and you can use that for the Rosetta Stone of the mind.

Once again, it all boils down to my own little specialty - the interface between emotions and cognition.

           Eliezer S. Yudkowsky
Running on BeOS           Typing in Dvorak          Programming with Patterns
Voting for Libertarians   Heading for Singularity   There Is A Better Way