There have been recent advances in computers’ abilities to understand human emotions. Whether that is recognizing facial expressions or detecting depression and happiness in human voice, machines are better able to interpret what humans do. The question all of this brings out, though, is something far more profound: Is it possible for a machine to feel; for a machine, for instance, to feel pain or to feel emotions?
This is at the core of the limit of what artificial intelligence may or may not be able to do. We use the word sentient usually to mean intelligent, but it actually means being able to sense things. And whereas you can make a sensor on a computer that can detect if heat has been applied to it, the question of whether a computer can feel pain is at the core of what is possible with artificial intelligence and an artificial general intelligence.