In human communication, pictures often complement a meaning of language. A picture represents an original item, but not exactly reflect it. There are various types of pictures. Some pictures are very realistic, whereas others are not. There is also difference in styles of drawing between cultures. Drawing skill will develop with practice, but an ability of recognition of pictures is equipped without previous experience (Hochberg & Brooks, 1962; Kennedy & Ross, 1975).
Captive great apes spontaneously draw with markers, paintbrushes, or with their fingers. Even 1-year-old infant chimpanzee drew with its finger on a touch panel monitor (Tanaka, in prep.). Almost all of works that the great apes were scribbles. There were very few that humans could recognize as a representation of something. Is it possible for great apes to recognize the pictorial representation, which are not used in their communication?
In this talk, I will discuss recognition of pictures in chimpanzees. The pictures were, of course, representations for humans. Three adult female chimpanzees (Ai, Mari, Pan) had been trained to choose photographs of flower among 12 photographs of objects (Tanaka, 2001, submitted). The subjects could choose almost perfectly. As the generalization test, the following three types of pictures were presented: 1) colored sketches (more realistic), 2) colored illustration, 3) black-and-white line drawings, and 4) Kanji characters (as a control condition). Only one chimpanzee (Ai) was able to choose any types of pictures of flowers significantly more often than chance, but her choices of the Kanji character corresponding to the flower were not different from chance. The other chimpanzee, Pan's performance was not different from chance in any types of pictures. The results suggest that not all chimpanzees could recognize the human-made pictorial representations without training. Ai had extensive prior experience in the use of visual symbols matched to various objects, colors, and numbers, whereas Pan had little experience. An ability of recognition of pictorial representation may relate to that of using symbols.

Hochberg, J. & Brooks, V. (1962). Pictorial Recognition as an unlearned ability: A study of one child's performance. American Journal of Psychology, 75, 624-628.
Kennedy, J. M. & Ross, A. S. (1975). Outline picture perception by the Songe of Papua. Perception, 4, 391-406.
Tanaka, M. (2001). Discrimination and categorization of photographs of natural objects by chimpanzees (Pan troglodytes). Animal Cognition, 4, 201-211.
Tanaka, M. (submitted for publication). Categorization of flowers in chimpanzees (Pan troglodytes).
Tanaka, M. (in prep.) Finger drawing in an infant chimpanzee.

TANAKA, Masayuki
Section of Language & Intelligence,
Primate Research Institute, Kyoto University
Kanrin, Inuyama, Aichi 484-8506, Japan
mtanaka@pri.kyoto-u.ac.jp