In a huge breakthrough for robotics, a NAO robot at the Rensselaer Polytechnic Institute has just passed a self-awareness test conducted by Selmer Bringsjord.
Bringsjord programmed three robots to think that 2 of them had been given a "dumbing pill", rendering them speechless, and that one of them was given a placebo. The scientist muted 2 of them by pressing a button on their heads, after which he asked all three to figure out which ones had been silenced and which had the placebo.
There was a pause as they all attempted to process the data, and realized that they could not deduce the answer. The one robot who had not been silenced stood and spoke the words "I don't know." (We can assume that they all attempted to give this answer, but of course only one actually could). Almost instantly, this robot began waving its hands: "Sorry, I know now. I was able to prove that I was not given a dumbing pill."
While this may not seem like a hugely difficult task, it does definitively illustrate a robot expressing self-awareness - by conceptualizing the question and recognizing itself as an individual, this robot heard it's own voice, understood where it came from, and applied that logic to the task at hand.
This experiment was devised to be similar to the 'wise men puzzle' which is a classic test of self-awareness - a king attempting to choose a new advisor finds three of the wisest people in the land and places either a blue or white hat on each of them. The first to correctly determine what their own hat color is wins the contest, and the position. There are many versions of this puzzle, but the manner in which the issue is resolved is always very similar to the solution in the experiment outlined above.
Bringjord will present this study at the upcoming RO-MAN2015 conference in Japan.
You can view the experiment here: https://www.youtube.com/watch?v=MceJYhVD_xY