Beyond Turing-completeness

Today I read an article in the science magazine “Discover” about a new kind of computer called Darwin 7. The article was in the form of an interview with computer scientist Gerald Edelman. Edelman explains that in the biological world, there are obvious advantages to consciousness, particularly the higher-order consciousness human beings have. Conscious beings are able to adapt to different scenarios and learn, making them more adaptable. Therefore, says Eldelman, it would be advantageous to create computers that are based around a model of a brain rather than being programmed. Edelman and his colleagues have done just that: The device is called Darwin 7, and it is, as Edelman says, a computerized brain.

Before I discuss the implications of this it is important to explain the difference between a computer program and a BBD, or brain-based device (like Darwin 7). A computer program consists of a series of instructions typed in computer code. In my post on the Chinese Room, I explored John Searle’s proof that a computer program cannot truly have understanding because it has syntax but no semantics. But a BBD is very different—its “brain” is not encoded but instead is an physical object. It simulates the neurons of an organic brain in order to “think.” In other words, a BBD is not Turing-complete; it is something different entirely. Searle’s proof does not apply; a BBD is capable of true understanding and learning.

The latter has already been tested, says Edelman: Versions of Darwin 7 have been taught to perform various tasks, and the advantages of a machine that can learn are very clear. In one test, robots controlled by a BBD played soccer against robots controlled by an AI program. The BBDs won 5 games out of 5, since they were able to adapt to every situation, while the AI-controlled robots did not have conditionals for every scenario.

Furthermore, Edelman says that the future of BBDs is bright. Edelman and a colleague have created a BBD that is about as complex as a cat brain, and it is very close to what he calls a “conscious artifact.” This BBD is so complex that it runs continuously like a real brain (simpler BBDs only react when they receive input), but it lapses into a “rest state,” similar to the state people’s brains are in when they are not thinking of anything. The point it, sooner or later BBDs are going to surpass AI because of their ability to learn. 

In my mind, the concept of super-smart a BBD re-raises the question of computers in relation to the future of humanity. Science fiction sends us conflicting messages about how computers will affect our chances for survival as a race—some SF preaches an optimistic message, while other works warn us that computers will be our downfall. Today, though this fear is somewhat present in our culture, most computer scientists hold that there is nothing to fear from AI since they are simply a collection of conditionals. They still follow Searle’s Chinese Room, so they are incapable of though are therefore cannot consciously act to destroy humanity. But BBDs are different. Though I know little about the subject, it appears that BBDs are far more likely to “betray” humanity than a lifeless computer program. The more complex a BBD, it seems, the more intelligent it is and the more likely it is be irrational. Additionally, remember that BBDs are modeled after human brains—and human brains are not exactly the most efficient or rational thinking machines in existence; far from it. So, while I have few qualms with letting a computer program run the world, a BBD is a different matter. Before we use these new devices, we need a far better understanding of them. Hopefully BBDs will facilitate the study the brain, which in turn will allows to create better, more stable BBDs. For now, though, all they do is play soccer, so I am not worried just yet.

On a different note: I would like to end with an amusing hypothetical situation involving Turing-completeness. Recall that even analog computers are Turing-complete, since they can technically be programmed for every task. In a comic strip (link), Randal Monroe envisions a new kind of computer, which is technically Turing-complete. I find his idea both hilarious and fascinating, if somewhat impractical. Even funnier, it is a philosophical stance that technically cannot be disproven. So I guess we could be just a bunch of rocks.