You might be interested in hearing about Washoe, a chimpanzee that was taught American Sign Language[1]. A particular quote from the entry: "When Washoe was shown an image of herself in the mirror, and asked what she was seeing, she replied: 'Me, Washoe.'"

Here's also a video on her, as well as Koko, a gorilla that was also taught ASL[2]

[1]http://en.wikipedia.org/wiki/Washoe_(chimpanzee) [2]http://www.youtube.com/watch?v=3V_rAY0g9DM