Embodied representations are known to influence user behavior in virtual environments through stereotypes associated with their appearance, a phenomenon known as the Proteus effect, or through perceived affordances. The latter concept refers to the suggested ways of interacting with the environment as perceived by the capabilities of the user's virtual representation. The inherent ability of virtual reality to support non-anthropomorphic avatars, enabling new interaction modalities, paves the way for a deeper understanding of affordances in virtual environments. We designed an experiment to assess the effect of embodying a chimeric hand (crab claw), compared to a regular hand, on participants' sense of embodiment, presence, character plausibility, mental workload, and behavior. Following a within-subject design, participants took part in a gamified task consisting of finding a key in a wrecked pirate ship. As the key could be hidden in containers of different durability, their strategy (opening or destroying objects) was used as an objective measure. Results indicated a high perceived usability and a low mental workload with both virtual limbs. Participants also performed hitting actions more frequently when using the biomimetic limb than when using the humanoid hand representation. A higher perceived change in the body schema was reported when embodying the crab claw, but a higher sense of body ownership and agency were observed with the anthropomorphic hand. Results revealed no significant difference in terms of plausibility.

The way users interact with Virtual Reality (VR) environments plays a crucial role in shaping their experience when embodying an avatar. How avatars are perceived by users significantly influences their behavior based on stereotypes, a phenomenon known as the Proteus effect. The psychological concept of affordances may also appear relevant when it comes to interact through avatars and is yet underexplored. Indeed, understanding how virtual representations suggest possibilities for action has attracted considerable attention in the human-computer interaction community, but only few studies clearly address the use of affordances. Of particular interest is the fact aesthetic features of avatars may signify false affordances, conflicting with users' expectations and impacting perceived plausibility of the depicted situations. Recent models of congruence and plausibility suggest altering the latter may result in unexpected consequences on other qualia like presence and embodiment. The proposed research initially aimed at exploring the operationalization of affordances as a tool to investigate the impact of congruence and plausibility manipulations on the sense of embodiment. In spite of a long and careful endeavor materialized by a preliminary assessment and two user studies, it appears our participants were primed by other internal processes that took precedence over the perception of the affordances we selected. However, we unexpectedly manipulated the internal congruence following repeated exposures (mixed design), causing a rupture in plausibility and significantly lowering scores of embodiment and task performance. The present research then constitutes a direct proof of a relationship between a break in plausibility and a break in embodiment.