2025 年 37 巻 4 号 p. 153-164
The shading and shadow of the face are essential information forming the impression of a person’s face. This study presented the facial carving illusion: although the face in the foreground is the same, the facial carving is perceived to be more profound when the background is changed. We demonstrated several examples of the contrast and intensity of natural backgrounds changing the depth perception of the nose. Furthermore, this study investigated the effect of background image statistics on the perception of facial carving under controlled laboratory conditions. The experiment revealed that the perception of facial carving is most pronounced when a low mean and large variation of the intensity distribution characterize the background. These results suggest that a dark background and high contrast enhance the perception of facial carving. We concluded that the facial carving illusion includes one of the phenomena of brightness assimilation.
