title: A comparison between two types of visually-evoked nystagmus in the monkey.
abstract: Similarities between optokinetic nystagmus (O.K.N.) and flicker-induced nystagmus (F.I.N.) include: response buildup and occurrence during the entire period of stimulation; absence of habituation; after-nystagmus in the same direction, occasional after-after-nystagmus to the opposite side; frequency spectrum, peak frequency and existence of lower and upper frequency thresholds. Phenomena are different in that for O.K.N. the stimulus is in motion; binocular and monocular stimulation are effective; direction is determined by direction of motion; unidirectionality is absent; there is minimal influence of background illumination, posture, labyrinthine receptors, and section of crossed optic fibers. For F.I.N. the stimulus is stationary; the response is elicited only by monocular stimulation; the direction is determined by the stimulated eye; there is exclusive unidirectionality; it is abolished by background illumination, optic chiasm section and bilateral labyrinthectomy; it is strongly influenced by posture. This comparison suggests that O.K.N. and F.I.N. are separate responses and that the effective stimulus for F.I.N. may activate selectively the crossed optic fibers.
mesh_terms: D000818:Animals; D007758:Ear, Inner / Q000502:physiology; D004584:Electronystagmography; D005133:Eye Movements; D000882:Haplorhini; D008029:Lighting; D008253:Macaca mulatta; D009897:Optic Chiasm / Q000502:physiology; D009900:Optic Nerve / Q000502:physiology; D009904:Optical Rotation; D010775:Photic Stimulation / Q000379:methods; D011187:Posture; D012399:Rotation; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception