Posed and spontaneous smile assessment with wearable skin conductance measured from the neck and head movement

Electro-Dermal Activity (EDA)and head movement have been shown to correlate with felt affect. Given the easiness to measure them, they are suitable as a wearable affective assessment tool. Arguably, autonomic affective responses such as EDA are less affected by volition than the production of other embodied cues of affect such as facial expressions. Moreover, head movement has been shown as a reliable source of information about the intention behind a facial expression. Therefore, we explored the feasibility of using EDA measured from the neck and head movement to make inferences about the nature of facial expressions, in particular, smiles. EDA was measured simultaneously from the hand and the neck of participants displaying spontaneous and posed smiles. Our results show that both measurement locations are highly correlated. Furthermore, EDA signals carry information about the spontaneity of the measured smiles, as shown by a classification accuracy of about 90%. Finally, head movement turned out to be rather revealing, with classification accuracy reaching about 99 %.