Automatic blush detection in 'concealed information' test using visual stimuli

Blushing has been identified as an indicator of deception, shame, anxiety and embarrassment. Although normally associated with the skin coloration of the face, a blush response also affects skin surface temperature. In this paper, an approach to detect a blush response automatically is presented using the Argus P7225 thermal camera from e2v. The algorithm was tested on a sample population of 51 subjects, while using visual stimuli to elicit a response, and achieved recognition rates of similar to 77% TPR and similar to 60% TNR, indicating a thermal image sensor is the prospective device to pick up subtle temperature change synchronised with stimuli.