ResearchPad - forehead Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Effect of aging and body characteristics on facial sexual dimorphism in the Caucasian Population]]> The aim of this study was to quantify gender-specific facial characteristics in younger and older adults and to determine how aging and body characteristics, such as height and body-mass index (BMI), influence facial sexual dimorphism.MethodsThe cohort study included 90 younger adults of Caucasian origin (average age of 45 females 23.2 ± 1.9 and 45 males 23.7 ± 2.4 years) and 90 older adults (average age of 49 females 78.1 ± 8.1 and 41 males 74.5 ± 7.7 years). Three-dimensional facial scans were performed with an Artec MHT 3D scanner. The data were analyzed using the software package Rapidform®. The parameters to evaluate facial symmetry, height, width, profile, facial shape, nose, eyes and mouth characteristics were determined based on 39 facial landmarks. Student’s t-test was used to calculate the statistical differences between the genders in the younger and older adults and a multiple-linear-regression analysis was used to evaluate the impact of gender, age, body-mass index and body height.ResultsWe found that the female faces were more symmetrical than the male faces, and this was statistically significant in the older adults. The female facial shape was more rounded and their faces were smaller, after normalizing for body size. The males had wider mouths, longer upper lips, larger noses and more prominent lower foreheads. Surprisingly, we found that all the gender-dependent characteristics were even more pronounced in the older adults. Increased facial asymmetry, decreased facial convexity, increased forehead angle, narrower vermilions and longer inter-eye distances occurred in both genders during aging. An increased BMI was associated with wider faces, more concave facial profiles and wider noses, while greater body height correlated with increased facial heights and wider mouths.ConclusionFacial sexual dimorphism was confirmed by multiple parameters in our study, while the differences between the genders were more pronounced in the older adults. ]]> <![CDATA[The Processing of Human Emotional Faces by Pet and Lab Dogs: Evidence for Lateralization and Experience Effects]]>

From all non-human animals dogs are very likely the best decoders of human behavior. In addition to a high sensitivity to human attentive status and to ostensive cues, they are able to distinguish between individual human faces and even between human facial expressions. However, so far little is known about how they process human faces and to what extent this is influenced by experience. Here we present an eye-tracking study with dogs emanating from two different living environments and varying experience with humans: pet and lab dogs. The dogs were shown pictures of familiar and unfamiliar human faces expressing four different emotions. The results, extracted from several different eye-tracking measurements, revealed pronounced differences in the face processing of pet and lab dogs, thus indicating an influence of the amount of exposure to humans. In addition, there was some evidence for the influences of both, the familiarity and the emotional expression of the face, and strong evidence for a left gaze bias. These findings, together with recent evidence for the dog's ability to discriminate human facial expressions, indicate that dogs are sensitive to some emotions expressed in human faces.