Retinal image is displaced by saccade, but we do not perceive any displacement of the world across saccade. The visual system must separate the retinal image displacement caused by saccade and that by actual stimulus displacement. A surrounding stimulus that covered a whole visual field would become a basis of the separation of the retinal image displacement across saccade. We investigated how a displacement perception of a test stimulus was influenced by a displacement of a surrounding stimulus. The point of subjective equality (PSE) for the perceived direction of the test displacement shifted to same direction of displacement of the surrounding stimulus.
