Production in visual non-verbal communication has been studied with the use of various research methods, both qualitative and quantitative. Whereas the former approach investigates the meaning and the structure of a gesture or a pantomime, the latter attempts to characterise low-level motion features in the production of visual non-verbal communication. In this presentation, we focus on the quantitative approach to the study of non-verbal behavior: we compare it with quantitative methods, highlighting main differences between the two approaches, present an overview of previous quantitative research methods, and identify the shortcomings of those methods. Finally, we propose a new method of studying non-verbal communication, which involves the application of motion capture systems, especially ones based on Inertial Measurement Units.

A commonly held assumption is that demonstration and pantomime differ from ordinary action in that the movements are slowed down and exaggerated to be better understood by intended receivers. This claim has, however, been based on meagre empirical support. This article provides direct evidence that different functional demands of demonstration and pantomime result in motion characteristics that differ from those for praxic action. In the experiment, participants were dressed in motion capture suits and asked to (1) perform an action, (2) demonstrate this action so that somebody else could learn how to perform it, (3) pantomime this action without using the object so that somebody else could learn how to perform it, and (4) pantomime this action without using the object so that somebody else could distinguish it from another action. The results confirm that actors slow down and exaggerate their movements in demonstrations and pantomimes when compared to praxis.

We rated video recordings of participants playing a charades-like semiotic game, where they took turns miming stories and picking the sequence of pictures that best suited what was mimed. The stories had one (male or female) or two characters (male and female). Although there was no pressure to disambiguate between the characters, most of the participants did so by producing iconic or indexical gender markers. Our analysis shows that when the gender of the characters in a story (the referent environment) matched the gender of the participants (the physical environment), the participants were more likely to use indexes rather than icons (p < 0.05, β = 1.4247). These results complement research on the role of the environment in the emergence of language-like structures and their systematicity in silent gesture tasks (e.g. Nölle et al. 2018).