Build-a-brain

 We could build an artificial brain that believes itself to be conscious. Does that mean we have solved the hard problem?

The brain is a machine: a device that processes information. That’s according to the last 100 years of neuroscience. And yet, somehow, it also has a subjective experience of at least some of that information. Whether we’re talking about the thoughts and memories swirling around on the inside, or awareness of the stuff entering through the senses, somehow the brain experiences its own data. It has consciousness. How can that be?

That question has been called the ‘hard problem’ of consciousness, where ‘hard’ is a euphemism for ‘impossible’. For decades, it was a disreputable topic among scientists: if you can’t study it or understand it or engineer it, then it isn’t science. On that view, neuroscientists should stick to the mechanics of how information is processed in the brain, not the spooky feeling that comes along with the information. And yet, one can’t deny that the phenomenon exists. What exactly is this consciousness stuff?

Here’s a more pointed way to pose the question: can we build it? Artificial intelligence is growing more intelligent every year, but we’ve never given our machines consciousness. People once thought that if you made a computer complicated enough it would just sort of ‘wake up’ on its own. But that hasn’t panned out (so far as anyone knows). Apparently, the vital spark has to be deliberately designed into the machine. And so the race is on to figure out what exactly consciousness is and how to build it.