Factors affecting the onset and magnitude of linear vection.

The role of central and peripheral vision in the production of linear vection was assessed by using displays in which flow structure and sources of internal and external depth information were manipulated. Radial optical flow was more effective for inducing self-motion in both central and peripheral visual fields than was lamellar flow in displays of the same size. The presence of external occlusion information was necessary to induce linear vection when small displays were composed of lamellar flow, whereas the effectiveness of small radial displays did not depend on the availability of occlusion edges.