Double body effect induced by integrating proprioceptive-vestibular and visual information.
Caleb Liang, Wen-hsiang Lin, Wei-kai Liou, Bo-yu Chen, Jie-rong Lin, Yen-tung Lee, Sufen Chen
iScience November 21, 2025 Peer reviewed DOI: 10.1016/j.isci.2025.113819 via PubMed
Summary
Healthy participants in virtual reality can experience owning and being located in two bodies simultaneously, a phenomenon called the Double Body Effect. In the experiments, participants wobbled involuntarily while watching two identical avatars performing the same movements. This effect occurred whether the avatars were seen from a first-person or third-person perspective. The findings indicate that body ownership and body location are more flexible than previously thought, and that self-location and body-location are distinct experiences. The results also suggest that the relationship between self and body is more complex than traditional dualism or contemporary reductionism, and may provide a preliminary model for understanding the puzzling experience of heautoscopy.
Study at a glance
| Design | experimental study |
|---|---|
| Population | healthy subjects |
| Key finding | Healthy subjects can experience the Double Body Effect, indicating that body ownership and body location are more flexible than previously considered. |
Abstract
Most studies in bodily self-consciousness were limited to the case of a single body. We performed VR experiments to test the hypothesis that it is possible for healthy subjects to experience the Double Body Effect-the experiential combination of double body ownership and double body-location. Under proprioceptive-vestibular and visual manipulations, participants wobbled involuntarily while watching two identical avatars doing exactly the same. The results showed that, in both the 1PP and 3PP conditions, it was indeed possible for healthy subjects to experience the Double Body Effect. This reveals that body ownership and body location are more flexible than most studies have considered so far. It also suggests that self-location and body-location are not the same experiences, and that the relation between self and body is more complicated than both traditional dualism and contemporary reductionism. Finally, our findings can serve as a preliminary model for understanding the perplexing phenomenology of heautoscopy.