Abstract
Humans perceive illusory self-motion when a coherent motion is presented in a large visual field (vection). It is dominated by a larger motion field, motion of the background, and non-attended motion, and enhanced by a perspective jitter (Kitazaki & Sato, 2003; Palmisano, et al., 2015). However, an effect of awareness to observer's own body has not been investigated. Illusory body ownership to an avatar in a virtual environment is elicited by contingent visual movements of the avatar body with the observer's action (Gonzalez-Franco, et al., 2010). We aimed to test if the awareness to the body ownership modulates vection in a virtual environment. In Experiment 1, ten naive subjects wore a head-mounted-display and observed a virtual room rotating around them to induce circular vection for 30s following a body ownership period for 300s. In the body ownership period, they were asked to move their legs and feet to step on randomly appearing circles. The avatar body in the virtual environment was visible and moved synchronously with subjects' action (visible condition) or invisible (invisible condition). Subjects performed four repetitions of the combination of the visibility condition (visible and invisible) and the directions (left and right). We found that the latency of vection was shorter (p=.070) and its duration was longer (p=.038) for the visible condition than the invisible condition. In Experiment 2, we used the synchronous condition that was identical to the visible condition in Experiment 1, and the asynchronous condition that the avatar moved independently of subjects' action for the body ownership period (n=9). The latency of vection was shorter (p=.022) and its duration was longer (p=.021) for the synchronous condition than the asynchronous condition. To conclude, the awareness to the own body or the sensation of body ownership with the visible and synchronously moving avatar enhances perception of vection.
Meeting abstract presented at VSS 2018