2008 年 26 巻 2 号 p. 186-193
In this paper, I summarize the series of experiments with chimpanzees (Pan troglodytes) on the perception and cognition of faces and related topics from the comparative-cognitive-developmental perspective. Chimpanzees show the face-specific inversion effect. Under the rotational matching paradigm, the chimpanzee showed longer response times when the sample and choice stimuli differed in orientation. In addition, they showed more efficient detection of upright faces among inverted ones than in the reversed condition. Furthermore, the face pops out from the other nonface objects. These results imply that the chimpanzees also process the face in a configural manner. Gaze is one of the most important information in the face. The chimpanzee showed efficient detection of direct-gaze face against the averted-gaze face (stare-in-the-crowd effect) but this discrimination was not extended to the discrimination of head orientations. Humans show the reflexive shift of visuospatial attention triggered by the gaze cues. A series of experiments, however, showed that the voluntary mechanism of attention shift was more dominant than reflexive one in chimpanzees.