Consciousness Considerations—Part 2 of a Trilogy

I find consciousness a fascinating topic. I've blogged about it here several times. One aspect of its allure for me—besides the fact that it is utterly basic to who we humans are and how we behave—is that even academic experts disagree on a definition. The field of consciousness research is very dynamic and broad. Our ability to probe into the workings of the brain by technologies, such as fMRI (functional magnetic resonance imaging) is rapidly expanding our knowledge base. Yet an agreed-upon definition or clarity of consciousness is still lacking among those authorities.

I think a core issue that is not often acknowledged in consciousness debates is that it's not so much whether or not some entity has consciousness, but what is its level of consciousness? It's not either/or; it's shades of gray. A bird is conscious, but certainly does not have the level of consciousness that most people do. Furthermore, we'll likely never penetrate the mind of a bird, in order to assess its level of consciousness. We have enough of a problem achieving this, human to human.

So how about a machine? Some artificial intelligence (AI) machines are becoming incredibly complex. Their software can be viewed as an aggregation of nodes interconnected by many pathways. That's very similar to our brain's nodes (neurons) and its pathways (axons, dendrites, and synapses). When will one of these AI machines possess enough nodes and interconnections to cross the threshold of consciousness? Would we even know? Could that type of consciousness be so alien that we'd not be able to recognize it?

Here's another way to look at it. Start with the human brain—something that we can confidently consider to be conscious. Cut it in half. Still conscious? Well, yes, some people's brains have been severed in half...they're still conscious. Keep cutting the brain in half. (Of course, this thought experiment assumes that the divided brain stays alive. So rather than cutting the brain apart, maybe imagine a critter whose brain has the same number of neurons as the repeatedly-cleaved human brain.) When do we reach a point when the brain fragment is no longer conscious? When the neurons are down from several hundred billion to a mere 100 million? A hundred thousand? 300? 75?

Or consider what happened on Earth, some time after life emerged. Were those first single-cell critters conscious? At what number of neurons and synapses did consciousness come into being? These are questions yet to be answered, if they ever can be. That's why I love science: just keep plugging away at the unknowns, and someday an answer will likely appear. Answers do exist—it's just that it's often very hard to locate them.

Completion of consciousness next time...