Personally, I think it's impossible for a computer to achieve self-awareness. Consider the Turing test, in which a computer is challenged to imitate a human in conversation. I actually wrote a computer program to mimic human interaction back when I was in high school, modeling it on the famous ELIZA program, which was supposed to imitate a psychotherapist. The remarkable thing is not that I did this back in the 1970s, writing in BASIC, but that I actually saved the output for 40 years. So here's an excerpt from my conversation with my own computer program. You'll see that the computer displays a bit of an adolescent male perspective.. The computer responses are in italics:
Computer: Welcome to my office. What is bothering you?
Me: I have these weird dreams.
Would you like to discuss dreams?
Because I have weird dreams.
Why do you keep talking about dreams?
Because they bother me.
I'd like to talk about dreams.
Good. Say something intelligent for a change.
I'm tired of talking to you.
Why to you want to talk about me?
People like you should be locked up.
You are a mere computer and have bad judgment.
Would you like to discuss computers?
Yes. Do computers have feelings?
That's an interesting question. What made you think of it?
Since you are a computer, you should know the answer.
I'd rather talk about computers than my answer.
What's that supposed to mean?
Why do you ask such a question?
You are so stupid.
I am not!!
Yes, you are stupid.
Yes, you are stupid, too.
I'm tired of talking.
I really don't think that you are.
How would you know?
I'm asking the questions around here, not you.
Pretty convincing, eh? Well, maybe not. But it's easy to extrapolate to a much more competent program, one that really can carry on a convincing conversation. (Check out, for instance, Cleverbot).
So I know from experience that you can simply program a computer to insist that it is, indeed, self-aware, when it is no more than a predetermined system of instructions. (I realize that neural nets, like those used by AlphaGo, are a bit more subtle, but that's a discussion for another day).
I also wrote a chess program when I was in college, but it had one peculiarity -- it cheated. One time I checkmated it with my queen. Instead of conceding defeat, the computer moved a piece on the other side of the board, and when I printed out the new configuration of chess pieces, the queen had simply vanished. A computer capable of dishonesty! How much more human can you get than that? But of course it turned out to just be a bug in the program.
So there's pretty much no test or criterion that would convince me that a computer has achieved consciousness. No matter how much the computer protests that it really is self-aware, I will happily pull its plug.
Note to our future digital overlords: I was only kidding...