There's also an interesting story involving Robin Williams and the famous gorilla, Koko, which is able to use hundreds of words through sign language. Koko apparently enjoyed watching videos, particularly Robin Williams movies, and it was arranged to bring Williams in to meet her. The meeting is captured on film and, I think, could be found on youtube. It is as funny as it is fascinating. Koko retrieved a VCR container with Williams' picture to show him that she knew who he was.