Aftereffect of induced rotation: number of radial lines in inducing stimulus.

Duration of aftereffect of induced rotation was shown to increase with the number of uniformly-spaced radial lines in an inducing stimulus. Possible explanations could be based on (a) the amount of shearing between radial lines in the inducing and static stimuli during adaptation, or (b) the angular displacement required for the inducing stimulus to assume again its initial form. Results for 5 women and 3 men from an inducing stimulus with non-uniformly spaced radial lines suggested that (a) was more important.