title: Optokinetic nystagmus: the effects of stationary edges, alone and in combination with central occlusion.
abstract: In Experiment 1 we investigated the independent and combined effects of horizontal OKN of stationary edges and occlusion of the central retina. For a display 60 degrees wide moving at 30 degrees/sec a symmetrically placed pair of vertical nonoccluding bars suppressed OKN when near the center of the display but had no effect when 30 degrees apart. A 7 degrees-high 60 degrees-wide central occluder reduced OKN gain by 37%. However, a central occluder with edges only 30 degrees wide abolished OKN. In Experiment 2 this interaction between central occlusion and stationary edges was confirmed with a wider display over a range of stimulus velocities and configurations. A functional explanation of this interaction is presented.
mesh_terms: D000328:Adult; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology; D009760:Nystagmus, Physiologic; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010470:Perceptual Masking / Q000502:physiology; D012160:Retina / Q000502:physiology*; D013997:Time Factors; D014792:Visual Acuity; D014794:Visual Fields