Penny Patterson with Koko the Gorilla
(Original Caption) "You key there me cookie." With that sign language, Koko the gorilla tells her mentor; 28-year old graduate student Penny Patterson, to get the key, open the closet and get a goodie out of the cookie jar. Here, Koko gives the "to listen" sign in sign-language, telling Penny she wants to listen to the phone. She doesn't know the real phone sign yet.