Eyebrow raises in dialogue and their relation to discourse structure, utterance function and pitch accents in English

Face-to-face interaction involves both verbal and non-verbal communication. Studies have suggested a relationship between eyebrow raises and the verbal message, but our knowledge is still limited. If we could characterise a relation between eyebrow raises and the linguistic signal we could better understand and reproduce human multimodal communication behaviour. Based on previous observations on body movement, this research investigated eyebrow raising in face-to-face dialogue in English in connection with (1) discourse structure and utterance function and (2) pitch accents. Small but significant results partially supported the predictions, suggesting a link between eyebrow raising and spoken language. Eyebrow raises occurred more frequently at the start of high-level discourse segments than anywhere else in the dialogue, and more frequently in instructions than in requests for or acknowledgements of information. Interestingly, contrary to the hypothesis queries did not have more raises than any other type of utterance. Additionally, as predicted, eyebrow raises seemed to be aligned with pitch accents, preceding them by an average of 0.06 s. Possible linguistic functions are proposed, namely the structuring and emphasising of information in the verbal message. Finally, methodological issues and practical applications are briefly discussed.