Facial coloration and temperature responses in blushing.

Little work on the psychophysiology of blushing has been done since Darwin's 1872 observations. Facial vascular and temperature changes have been largely ignored in psychophysiology. We had 16 female and 16 male undergraduate volunteers watch a videotape intended to produce blushing (the individual's singing recorded the previous day), and a videotape not intended to produce blushing, but elicit physiological responses for comparison (a segment from Hitchcock's movie Psycho). Four people were present as a subject watched these video segments. Cheek and ear coloration, measured photoplethysmographically, cheek temperature, and finger skin conductance responses were significantly greater during stimulation intended to elicit blushing than during comparison stimulation. Gender interacted statistically with kind of stimulation only in cheek temperature. Only video segments of the subject's face that coincided with maximal cheek coloration during stimulation intended to produce blushing were judged reliably as blushing, and then more often in females than in males.