A Role for Contrast Gain Control in Skin Appearance

Apparent contrast can be suppressed or enhanced when presented within surrounding images. This contextual modulation is typically accounted for with models of contrast gain control. Similarly, the appearance of one part of a face is affected by the appearance of the other parts of the face. These influences are typically accounted for with models of face-specific holistic processing. Here we report evidence that facial skin appearance is modulated by adjacent surfaces. In four experiments we measured the appearance of skin evenness and wrinkles in images with increased or decreased contrast between facial skin and adjacent image regions. Increased contrast with adjacent regions made facial skin appear more even and less wrinkled. We found the effect whether faces were presented upright or inverted, and also when facial features were not present, ruling out face-specific holistic processing as an explanation yet fully consistent with contrast gain control. Because the mechanism is not face specific, contrast between skin and any adjacent surface should affect skin appearance. This suggests that adornments such as makeup, hair coloring, clothing, and jewelry could also affect skin appearance through contrast suppression or enhancement, linking these cultural practices to the structure and function of the visual system

Makeup Changes the Apparent Size of Facial Features

Makeup is a prominent example of the universal human practice of personal decoration. Many studies have shown that makeup makes the face appear more beautiful, but the visual cues mediating this effect are not well understood. A widespread belief holds that makeup makes the facial features appear larger. We tested this hypothesis using a novel reference comparison paradigm, in which carefully controlled photographs of faces with and without makeup were compared with an average reference face. Participants compared the relative size of specific features (eyebrows, eyes, nose, mouth) of the reference face and individual faces with or without makeup. Across three studies we found consistent evidence that eyes and eyebrows appeared larger with makeup than without. In contrast, there was almost no evidence that the lips appeared larger with makeup than without. In two studies using professionally applied makeup the nose appeared smaller with makeup than without, but in a study using self-applied makeup there was no difference. Thus makeup was found to alter the facial feature sizes in ways that are related to age and sex, two known factors of beauty. These results provide further evidence to support the idea that makeup functions in part by modifying biologically based factors of beauty

Cosmetics Increase Skin Evenness: Evidence from Perceptual and Physical Measures

Background Cosmetics are commonly attributed with increasing skin evenness, yet little published data characterizes the effect, either perceptually or physically. We therefore investigated whether makeup increases skin evenness using a perceptual measurement and two physical measurements of color and luminance homogeneity. Materials and Methods Twenty‐two French women (aged 29‐45 years) were photographed without cosmetics, with self‐applied cosmetics, and with professionally‐applied cosmetics. In Study 1, 143 participants rated skin evenness. In Study 2, each face was delineated to create regions of interest (ROI) in the cheek and forehead areas. Both ROIs were then analyzed for luminance homogeneity using an established measure (Haralick homogeneity) and a new measure that incorporates chromaticity (H76). Results In Study 1, the faces were rated as having more even‐looking skin with either self‐applied cosmetics or professionally‐applied cosmetics than without cosmetics. In Study 2, the luminance homogeneity measure found that the cheek ROI, but not the forehead ROI, was more homogeneous after both self‐applied cosmetics and professionally‐applied cosmetics when compared to without cosmetics. The new measure incorporating chromaticity found greater homogeneity in both ROIs in the two cosmetics conditions. The new measure incorporating chromaticity also better predicted the perceived skin evenness ratings from Study 1. Conclusion These results provide systematic empirical evidence that makeup increases perceived skin evenness, and that these increases are partly predicted by physical measurements of skin luminance and color. The data also indicate that H76—the new measure of skin evenness that incorporates chromaticity—better predicts perceived skin evenness

Positive Facial Affect Looks Healthy

A healthy appearance is linked to important behavioural outcomes. Here we investigated whether positive facial affect is a cue for perceived health. In study one, two groups of participants rated the perceived health or perceived happiness of a large set of faces with neutral expressions. Perceived happiness predicted perceived health, as did anthropometric measures of expression. In a second experimental study, we collected ratings of perceived health for a wide age range of target faces with either neutral or smiling expressions. Smiling faces were rated as being much healthier looking than neutral faces, confirming that facial expression plays a role in the perception of health. A third study investigating attractiveness as a possible mediator found that expression still had a significant direct effect on perceived health, after accounting for attractiveness. Together, these studies systematically show that facial affect plays a critical role in shaping our perceptions of health in others

Coloration in different areas of facial skin is a cue to health: The role of cheek redness and periorbital luminance in health perception

Looking healthy is a desirable trait, and facial skin color is a predictor of perceived health. However, skin conditions that cause dissatisfaction with appearance are specific to particular facial areas. We investigated whether color variation in facial skin is related to perceived health. Study 1 defined three areas based on color differences between faces perceived as healthy or unhealthy: the forehead, periorbital areas, and the cheeks. Periorbital luminance and cheek redness predicted perceived health, as did global skin yellowness. In Study 2, increased luminance and redness caused faces to be perceived as healthier, but only when the increase was in the periorbital and cheek areas, respectively. Manipulating each area separately in Study 3 revealed cheek redness and periorbital luminance equally increased perceived health, with low periorbital luminance more negatively affecting perceptions. These findings show that color variation in facial skin is a cue for health perception in female faces

Facial Contrast Is a Cross-Cultural Cue for Perceiving Age

International audienceAge is a fundamental social dimension and a youthful appearance is of importance for many individuals, perhaps because it is a relevant predictor of aspects of health, facial attractiveness and general well-being. We recently showed that facial contrast—the color and luminance difference between facial features and the surrounding skin—is age-related and a cue to age perception of Caucasian women. Specifically, aspects of facial contrast decrease with age in Caucasian women, and Caucasian female faces with higher contrast look younger (Porcheron et al., 2013). Here we investigated faces of other ethnic groups and raters of other cultures to see whether facial contrast is a cross-cultural youth-related attribute. Using large sets of full face color photographs of Chinese, Latin American and black South African women aged 20–80, we measured the luminance and color contrast between the facial features (the eyes, the lips, and the brows) and the surrounding skin. Most aspects of facial contrast that were previously found to decrease with age in Caucasian women were also found to decrease with age in the other ethnic groups. Though the overall pattern of changes with age was common to all women, there were also some differences between the groups. In a separate study, individual faces of the 4 ethnic groups were perceived younger by French and Chinese participants when the aspects of facial contrast that vary with age in the majority of faces were artificially increased, but older when they were artificially decreased. Altogether these findings indicate that facial contrast is a cross-cultural cue to youthfulness. Because cosmetics were shown to enhance facial contrast, this work provides some support for the notion that a universal function of cosmetics is to make female faces look younger

Towards Continuous Health Diagnosis from Faces with Deep Learning

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Understanding the visual effects of cosmetic products on beauty via Deep Learning

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