Sharp Body, Sour Taste: Changing Taste Experiences Through Cross-Modal Correspondence With the Bouba/Kiki Self-Avatar...

Cross-modal correspondence, exemplified by the Bouba/Kiki effect, which refers to the association between linguistic sounds and visual shape impressions, is known to influence taste perception. Previous studies have shown that taste perception varies with the visual features of foods, beverages, and tableware. However, it remains unclear how embodying a self-avatar in virtual reality (VR) whose visual features are associated with Bouba/Kiki influences taste perception. We conducted two studies to investigate the effects of cross-modal correspondence between VR self-avatar characteristics and taste perception using lemon-flavored carbonated beverages that elicit both sweetness and sourness. Study 1 directly compared Bouba avatars (round shapes, red colors, slow animations) and Kiki avatars (angular shapes, yellow colors, fast animations) in a within-participants design ($N = 36$N=36). Study 2 examined the effects of each avatar type separately by comparing them with neutral control conditions ($N = 72$N=72). In Study 1, the Bouba avatar led participants to perceive the beverage as mellower compared to the Kiki avatar. However, this effect was not significant when compared with a neutral control avatar in Study 2. In contrast, the Kiki avatar produced robust effects, increasing perceived sourness and sharpness in both studies. These findings suggest that the observed changes in taste are primarily driven by the congruence between avatar characteristics and the intrinsic sensory properties of the beverage. This study demonstrates the potential for avatar-mediated congruence effects to alter perceived taste in VR, highlighting the importance of the alignment between the user's virtual body and the consumed stimulus.