Background: Previous studies have suggested that color and thermal changes in face and body are triggered by various forms of emotional arousal such as fear, pride as well as sexual arousal. Two phenomenons are related to color changes in the face - blushing and sex flush, but the continuity between these two types is unknown.
Our study aimed to test color and thermal changes in women face during emotional and sexual imagery. Methods: Color and thermal reactions of 21 women (mean age = 23.9, SD=4.9) on their face and neck were recorded in standardized conditions using a digital SLR camera and thermal imaging camera.
After a 15 minutes baseline measurement, women were led to imagine 5 different scenarios: embarrassment, pride, courtship, body-focused sexual arousal and sexual fantasy. The content of the imagination was based on participants' own experiences, the order of scenarios was randomized.
Analysis: For each condition, the moment with the strongest observed emotion was chosen for analysis. The skin temperature and color was examined in six selected regions (ROIs) on face and neck - forehead, eyes, nose, cheeks, mouth and upper chest.
Results: Though there was no significant relationship between temperature and color, all experimental scenarios caused changes in redness and temperature. Compared to the baseline, significant increase in temperature were measured in all ROIs in embarrassing and body focused sexual arousal scenarios (all p > .001).
The significant increase in facial skin redness were found in all ROIs in both sexual conditions and courtship situation (all p > .001), compared to the baseline. Conclusion: Our study showed that all experimental situations triggered some temperature and color changes in participants' face and neck areas.
Changes in skin redness are visible and therefore might serve as cue, e.g. for recognizing excitement (e.g, sexual arousal) of a given individual.