Negative aftereffect arising from prolonged viewing of induced movement-in-depth.

Prolonged induced movement-in-depth in a static circle was elicited by a spiral stimulus. Afterwards an aftereffect was observed in the circle. The aftereffect was towards the subject after induced movement away from the subject, and away from the subject after induced movement towards the subject. Longer aftereffect was observed with a circle central to the inducing stimulus than with a circle peripheral to the inducing stimulus. In contrast to some other psychophysical effects, no clear-cut directional asymmetry was observed.