After Effect of Seen Movement: Evidence for Peripheral and Central Components

Three experiments showed that the movement after-effect (MAE) contains both peripheral and central components. In Experiment I, the left eye viewed a sectored disc rotating to the left, and the right eye viewed a disc rotating to the right, on corresponding retinal areas. Result: when each eye in turn then viewed a stationary disc, the left eye saw a MAE to the right, and the right eye a MAE to the left. These MAEs must be peripheral. In Experiment II, it was arranged that the movement information was shared out between the eyes, using a ring of lights which were switched on and off to give rotating phi movement. It was arranged that each eye on its own saw a random flashing oscillation but the two eyes together saw rotation anticlockwise. Result: a clockwise MAE was seen, which must be central. In Experiment III, the switching programme was modified to arrange that now each eye on its own saw rotation clockwise, but the two eyes together saw rotation anticlockwise. Result: a clockwise MAE was seen, which must be central. (Peripheral MAEs from each eye on its own would have been anticlockwise.)