Most afternoons, you'll find 81-year-old Tom Clark snoozing with his pet cat, Aspen, on his lap. However, this cat doesn't need to be fed or let outside. Aspen, the name of a cat he once had, isn't real, but he just loves it. Aspen is a robotic cat with artificial intelligence built in, designed to do normal cat stuff like stretch, purr and roll on its back. "Sometimes, they'll even ignore you the way a cat might, typically," explains psychologist Dr. Caitlin Holly. She started using these robotic pets about two months ago with dementia patients at Albany, New York's...