Various lines of evidence (signed languages, emotional signalling) suggest that eyebrow and other upper-face movements may have specifiable functions in communication. However, research on the relation between such movements and spoken language is still scarce. This study starts from the assumption that eyebrow raises have linguistic (not just emotional) functions, and tests the specific hypothesis that such movements will be distributed unequally across different types of "conversational move" (asking a yes-no question, giving an instruction, acknowledging information, etc.). Preliminary analysis of six dialogues between participants performing a standard cooperative experimental task (the Map Task) confirmed this hypothesis: eyebrow raises were significantly more common when speakers were giving out instructions or providing an explanation than when they were replying to a query or acknowledging information. The difference does not appear to depend simply on differences in the length of the various types of conversational move. Further research is in progress, with a larger set of data and a more accurate annotation tool. One eventual application of this work will be the more efficient engineering of multimodal communication systems.