Can a robot ever be conscious and how would we know if it were?
Some people think we could easily build and identify a conscious robot, while others insist that its impossible  it all depends on what you think consciousness is. Yuichiro Chino/Getty Images  There is disagreement over whether machines can ever be conscious, let alone how we would know if one were. Your view may depend on how you see consciousness. If the subjective feeling of consciousness is an illusion created by brain processes, then machines that replicate such processes would be conscious in the way that we are. Daniel Dennett at Tufts University in Massachusetts thinks a Turing test, in which a machine has to convince a human interrogator that it is conscious, should, if conducted with suitable vigour and aggression and cleverness, be enough. Michael Graziano at Princeton University thinks we could take a more direct approach. His attention schema hypothesis sees consciousness as the brains simplified model of its own workings  a representation of how it represents things. He believes it is possible to build a machine that possesses a similar self-reflective model. If we can build it in a way that we [can] see into its guts, then we will know this is a machine that has a rich self-description, he says. It is a machine that thinks and believes it has consciousness. And those are confirmable because you can understand, in principle, how the machine is processing information.  For Graziano, consciousness could appear in any machine, whether it is purely in software or 