On the way to artificial conscousness


Discovery magazine had an interview by Susan Kruglinski with Gerald Edelman, What Makes You Uniquely ‘You’? (here). Here is another part of Edelman’s ideas – how to make artificial consciousness.

“The cortex is responsible for a good degree of the contents of consciousness, and if I take out an awful lot of cortex, there gets to be a point where it’s debatable as to whether you’re conscious or not.

For example, there are some people who claim that babies born without much cortex—a condition called hydran­encephaly—are still conscious because they have their midbrain. It doesn’t seem very likely. There’s a special interaction between the cortex and the thalamus, this walnut-size relay system that maps all senses except smell into the cortex. If certain parts of the thalamo­cortical system are destroyed, you are in a chronic vegetative state; you don’t have consciousness. That does not mean consciousness is in the thalamus, though.

If you touch a hot stove, you pull your finger away, and then you become conscious of pain, right? So the problem is this: No one is saying that consciousness is what causes you to instantly pull your finger away. That’s a set of reflexes. But consciousness sure gives you a lesson, doesn’t it? You’re not going to go near a stove again. As William James pointed out, consciousness is a process, not a thing.”

I like the reference to the thalamocortical system!!

 

“If we ever create a conscious artifact, it won’t be living. That might horrify some people. How can you have consciousness in something that isn’t alive? There are people who are dualists, who think that to be conscious is to have some kind of special immaterial agency that is outside of science. The soul, floating free—all of that.

There might be people who say, “If you make it conscious, you just increase the amount of suffering in this world.” They think that consciousness is what differentiates you or allows you to have a specific set of beliefs and values. You have to remind yourself that the body and brain of this artifact will not be a human being. It will have a unique body and brain, and it will be quite different from us…

We construct what we call brain-based devices, or BBDs, which will be increasingly useful in understanding how the brain works and modeling the brain. They may also be the beginning of the design of truly intelligent machines.

It looks like maybe a robot, R2-D2 almost. But it isn’t a robot, because it’s not run by an artificial intelligence [AI] program of logic. It’s run by an artificial brain modeled on the vertebrate or mammalian brain. Where it differs from a real brain, aside from being simulated in a computer, is in the number of neurons. Compared with, let’s say, 30 billion neurons and a million billion connections in the human cortex alone, the most complex brain-based devices presently have less than a million neurons and maybe up to 10 million or so synapses, the space across which nerve impulses pass from one neuron to another. Our brain-based device learned to pick up a ball and kick it back to a human colleague. It did not just execute algorithms…

An artificial intelligence program is algorithmic: You write a series of instructions that are based on conditionals, and you anticipate what the problems might be. AI robot soccer players make mistakes because you can’t possibly anticipate every possible scenario on a field. Instead of writing algorithms, we have our BBDs play sample games and learn, just the way you train your dog to do tricks.

At the invitation of the Defense Advanced Research Projects Agency, we incorporated a brain of the kind that we were just talking about into a Segway transporter. And we played a match of soccer against Carnegie Mellon University, which worked with an AI-based Segway. We won five games out of five. That’s because our device learned to pick up a ball and kick it back to a human colleague. It learned the colors of its teammates. It did not just execute algorithms.

It seems to work better to build in a sort of consciousness.

 

“The brain can be simulated on a computer, but when you interface a BBD with the real world, it has the same old problem: The input is ambiguous and complex. What is the best way for the BBD to respond? Neural Darwinism explains how to solve the problem. On our computers we can trace all of the simulated neuronal connections during anything the BBD does. Every 200 milliseconds after the behavior, we ask: What was firing? What was connected? Using mathematical techniques we can actually see the whole thing converge to an output. Of course we are not working with a real brain, but it’s a hint as to what we might need to do to understand real brains.

Eugene Izhikevitch [a mathematician at the Neurosciences Institute] and I have made a model with a million simulated neurons and almost half a billion synapses, all connected through neuronal anatomy equivalent to that of a cat brain. What we find, to our delight, is that it has intrinsic activity. Up until now our BBDs had activity only when they confronted the world, when they saw input signals. In between signals, they went dark. But this damn thing now fires on its own continually. The second thing is, it has beta waves and gamma waves just like the regular cortex—what you would see if you did an electroencephalogram. Third of all, it has a rest state. That is, when you don’t stimulate it, the whole population of neurons stray back and forth, as has been described by scientists in human beings who aren’t thinking of anything.

In other words, our device has some lovely properties that are necessary to the idea of a conscious artifact. It has that property of indwelling activity. So the brain is already speaking to itself. That’s a very important concept for consciousness.”

If you can make something – you can understand it. This work is on the way to understanding consciousness.

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