OPTOKINETIC REACTIONS OF THE RABBIT - RELATION TO THE VISUAL STREAK

The effectiveness of different parts of the retina in mediating optokinetic tracking of a moving pattern (OKN) has been tested with relatively small random dot patterns (diameter 30°) that were moved in eight directions. The retinal location of the stimulus was fixed by immobilization of the eye or by servo-control of the stimulus position by the eye position. The area of maximal optokinetic sensivity was coextensive with the visual streak. The total sensitive area extended between 50° superior. 10° inferior, 75° posterior and 100° anterior in the visual field of one eye. Beyond this area no OKN could be elicited. OKN smooth phase velocity was maximal for stimulation in anterior direction, about 3 times smaller for vertical movement and 20 times smaller for posterior movement. Only the cooperation of the two eyes can assure balanced responses in all directions. Such a design supports the function of the rabbit's OKN in global stabilization, but is unsuitable for the pursuit of small objects. © 1979.