Publications by authors named "Rosalyn M Schneider"

Human eyes move continuously, even during visual fixation. These "fixational eye movements" (FEMs) include microsaccades, intersaccadic drift and oculomotor tremor. Research in human FEMs has grown considerably in the last decade, facilitated by the manufacture of noninvasive, high-resolution/speed video-oculography eye trackers.

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When normal subjects fix their eyes upon a stationary target, their gaze is not perfectly still, due to small movements that prevent visual fading. Visual loss is known to cause greater instability of gaze, but reported comparisons with normal subjects using reliable measurement techniques are few. We measured binocular gaze using the magnetic search coil technique during attempted fixation (monocular or binocular viewing) of 4 individuals with childhood-onset of monocular visual loss, 2 individuals with late-onset monocular visual loss due to age-related macular degeneration, 2 individuals with bilateral visual loss, and 20 healthy control subjects.

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Prior studies indicate that the human translational vestibulo-ocular reflex (tVOR) generates eye rotations approximately half the magnitude required to keep the line of sight pointed at a stationary object--a compensation ratio (CR) of ∼0.5. We asked whether changes of visual or vestibular stimuli could increase the CR of tVOR.

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The cerebellum plays an important role in programming accurate saccades. Cerebellar lesions affecting the ocular motor region of the fastigial nucleus (FOR) cause saccadic hypermetria; however, if a second target is presented before a saccade can be initiated (double-step paradigm), saccade hypermetria may be decreased. We tested the hypothesis that the cerebellum, especially FOR, plays a pivotal role in programming sequences of saccades.

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