Aftereffects from jogging.

After running on a treadmill, runners who attempted to jog in place on solid ground inadvertently jogged forwards. One-legged hopping on the treadmill produced an aftereffect in the same leg, but not in the other leg. This non-transfer suggests a peripheral neural site. Judgments of velocity and slope were affected; running on a backward-moving treadmill made a stationary test treadmill seem to move forwards, and running on an uphill-sloping treadmill made a horizontal test treadmill seem to slope downhill. These aftereffects suggest an automatic gain control process.