Ballard and Denny-Brown Laboratories, Harvard Neurological Unit, Beth Israel Hospital, Boston, Massachusetts 02215, U.S.A.
Abstract:
Rhesus monkeys were trained on a variety of simultaneous two-choice visual discrimination tasks to assess their ability to utilize pictures of other rhesus monkey faces as discriminative stimuli. The results revealed that this non-human primate is particularly adept at making such discriminations and is not confused by manipulations in orientation; posture; size; color; or illumination.