Sharing spatial information in a virtual environment: How do visual cues and configuration influence spatial coding and mental workload?

International audience; When sharing virtual collaborative environments, operators exchange spatial statements that refer to the objects’ positions in the virtual space. If operators are to understand each other, they need to develop a common spatial frame of reference and then choose a space coding to describe the objects’ positions. In this paper, we consider how the content of a virtual environment can influence communication between users. We designed two studies in which one participant (the speaker) had to indicate the position of one object to another participant (the addressee). The virtual environment was sometimes enriched by additional (proximal and distal) visual cues. In study 1, we considered statements production. We observed that the speakers most often used the avatar of their partner as a spatial reference to indicate a localization in the virtual space (i.e., Addressee-Centered coding) despite it increases their mental workload. Nevertheless, in complex situations, they also used distal cues to speak to the addressees (i.e., Exocentric coding of the space). In study 2, we considered statements comprehension. Addressee-Centered coding and Exocentric coding were used by the speakers in various spatial configurations to indicate the object position. We observed that Exocentric coding is the most difficult to manage for the addressee. These results indicate that speakers implemented the principle of less collaborative effort by adopting a way of exchanging information based on an asymmetrical cognitive cost, taking into consideration each other’s difficulties. This allows a balanced mental workload to be maintained between the two operators throughout the task.