Relationship between the individual differences in curved-surfaceaftereffect (CS-AE) and equilibrioception performance is investigated. Subjects with a rigid perception of CS-AE have rich sporting experience and so can integrate visual and gravity sensory systems well. Some of them can perceive CS-AE when viewing narrow angle images in addition to wide ones.

We tested the footsteps illusion under both occluding-and occluded-conditions in 2D and 3D environments. Experiments suggest that 1) object contours have an essential role, and 2) the illusion is not perceived as the simple consequences of edgecontrast deterioration but is the result of top-down reinforcement learning triggered by attention.