Neural basis of the spontaneous optokinetic response produced by visual inversion.

One of the most conspicuous behavioral effects produced by surgical rotation of the eyeball through 180 degrees is the forced circling or spontaneous optokinetic reaction. Animals with inverted vision caused by eye rotation tend to turn continuously in circles (4, 6, 8). In fishes and amphibians this circling may persist indefinitely with little or no correction by reeducation. Similar circus movement is caused by contralateral transplantation of the eyeball with inversion on only one axis and also by cross-connection of the optic nerves to the wrong side of the brain (7). In all these situations movement on the part of the animal causes the visual image to pass over the retinal field or its central projection in a direction opposite to normal. The forced circling phenomenon of inverted vision is an illustration of the importance of kinesthetic effects in visual perception. Under normal conditions the image of the visual field, whether it be stationary or moving across the retina, can be perceived as being either in motion or at rest depending upon whether the perceiving animal is moving or at rest. The apparent position and direction of motion of the visual field depend upon the posture