Nested Moving Room が立位姿勢の視覚制御に与える影響

抄録

Ecological studies on the impacts of global optical flow (GOF) on posture have long employed the Moving Room experimental paradigm, in which the surfaces surrounding participants (except for the floor) oscillate back and forth. Although the accumulated results are insightful, these set-ups have used fully enclosed rooms without windows, and thereby, the effects of apertures connecting the room interior to an exterior environment remain unknown. To address this gap, the present study used virtual reality (VR) to construct a Nested Moving Room (NMR), in which an inner room was surrounded by an outer wall, and the two were connected by apertures of varying sizes. Two within-participant factors were manipulated: aperture pattern (three levels: no aperture, window aperture, and full aperture) and oscillation pattern (three levels: room oscillation, outside oscillation, and no oscillation). The results showed that room oscillations in the no-aperture condition induced strong feelings of self-motion and increased body sway, replicating the classical Moving Room effect. This effect was maintained under the window-aperture condition but was attenuated under the full-aperture condition. Furthermore, cross-recurrence quantification analysis (CRQA) revealed that the window-aperture condition yielded relatively high coupling stability (Lmax) and determinism (DET) between head sway and environmental oscillation. These findings suggest that apertures in the nested room walls alter the structure of optical flow available for posture maintenance, and that the occlusion relationships at the aperture edges may provide additional visual information that enhances the dynamic stability of postural control.