Communication Effects and Functions of Nonverbal Movements in Video-Mediated Guessing Task

This paper aimed to explore the functional effects and characteristics of nonverbal body movements in communication via a bidirectional video system. In the present study we carried out the experiment where two subjects assigned specific roles (an explainer and a solver) in advance communicated for achieving their given objective. In order to control the communication developed in the experiment, we devised a new communication model called "the guessing model" for specifying the objective, the rules and the explainer's initial mental model. The subjects' objective was that the explainer explained a Japanese place for sight-seeing using only nonverbal body movements and the solver guessed it. The scenes of both communication sites were videorecorded and only the body movements of the subjects were analyzed. Objects representing a piece of information were classified into ones that can be plainly expressed (expressible information) and ones that cannot be plainly expressed (inexpressible information), and the process of the communication was split into three sorts of sections according to whether the interaction between the subjects was successful, failed or deadlocked. These objects and sections were related to Ekman's functional categories of body movements. Plainly expressible objects could be conveyed effectively and correctly by a small number of emblems and illustrators. Frequent occurrence of regulators and adaptors significantly prolonged the communication and meant that the subjects were puzzled what and how to communicate or that the interaction was deadlocked.