How does this primary consciousness contrast with the self-consciousness that seems to define people?
Humans are conscious of being conscious, and our memories, strung together into past and future narratives, use semantics and syntax, a true language. We are the only species with true language, and we have this higher-order consciousness in its greatest form. If you kick a dog, the next time he sees you he may bite you or run away, but he doesn’t sit around in the interim plotting to remove your appendage, does he? He can have long-term memory, and he can remember you and run away, but in the interim he’s not figuring out, “How do I get Kruglinski?” because he does not have the tokens of language that would allow him narrative possibility. He does not have consciousness of consciousness like you.
How did these various levels of consciousness evolve?
About 250 million years ago, when therapsid reptiles gave rise to birds and mammals, a neuronal structure probably evolved in some animals that allowed for interaction between those parts of the nervous system involved in carrying out perceptual categorization and those carrying out memory. At that point an animal could construct a set of discriminations: qualia. It could create a scene in its own mind and make connections with past scenes. At that point primary consciousness sets in. But that animal has no ability to narrate. It cannot construct a tale using long-term memory, even though long-term memory affects its behavior. Then, much later in hominid evolution, another event occurred: Other neural circuits connected conceptual systems, resulting in true language and higher-order consciousness. We were freed from the remembered present of primary consciousness and could invent all kinds of images, fantasies, and narrative streams.
So if you take away parts of perception, that doesn’t necessarily take away the conceptual aspects of consciousness.
I’ll tell you exactly—primitively, but exactly. If I remove parts of your cortex, like the visual cortex, you are blind, but you’re still conscious. If I take out parts of the auditory cortex, you’re deaf but still conscious.
But consciousness still resides in the brain. Isn’t there a limit to how much we can lose and still lay claim to qualia—to consciousness—in the human sense?
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.
Can consciousness be artificially created?
Someday scientists will make a conscious artifact. There are certain requirements. For example, it might have to report back through some kind of language, allowing scientists to test it in various ways. They would not tell it what they are testing, and they would continually change the test. If the artifact corresponds to every changed test, then scientists could be pretty secure in the notion that it is conscious.
At what level would such an artifact be conscious? Do you think we could make something that has consciousness equivalent to that of a mouse, for example?
I would not try to emulate a living species because—here’s the paradoxical part—the thing will actually be nonliving.
Yes, but what does it mean to be alive?
Living is—how shall I say?—the process of copying DNA, self-replication under natural selection. 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.
If you could combine a conscious artifact with a synthetic biological system, could you then create an artificial consciousness that is also alive?
Who knows? It seems reasonably feasible. In the future, once neuroscientists learn much more about consciousness and its mechanism, why not imitate it? It would be a transition in the intellectual history of the human race.
Do you believe a conscious artifact would have the value of a living thing?
Well, I would hope it would be treated that way. Even if it isn’t a living thing, it’s conscious. If I actually had a conscious artifact, even though it was not living, I’d feel bad about unplugging it. But that’s a personal response.
