Skin appearance is affected by local contrast

摘要

Skin appearance heavily influences perceptions of age, health, and attractiveness. We observed anecdotally that faces appear to have more even skin tone and fewer wrinkles when the facial features are digitally darkened (increasing the contrast between the facial features and the surrounding skin) or when makeup is applied to the facial features but not to the skin. We confirmed this in two studies by collecting ratings of the evenness and wrinkliness of facial skin, one study with digitallymanipulated facial features and the other study with makeup applied to the eyebrows, eyes, and lips, but not the skin. This effect could be due to face-specific visual processes or to lower-level visual processes like contrast gain control. Because face-specific visual processes are disrupted by inverted orientation, we conducted a third study inverting the face images with darkened or lightened facial features. Darkened features again resulted in the skin appearing more even and less wrinkled, contradicting the notion that this effect is due to face-specific processes. In a fourth study we added varying amounts of local contrast to face images by placing them behind occluding bars that were either black or skin-toned. Faces were perceived to have more even skin and fewer wrinkles when behind black bars, further supporting the notion that skin appearance is affected by contrast via lower-level visual processes. Collectively these findings demonstrate that skin appearance is affected by contrast with facial features and other adjacent surfaces, shedding light on face perception and practices of decoration such as makeup.