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dc.creatorLEVY, JOEL KUTNER
dc.date.accessioned 2007-05-09T19:35:53Z
dc.date.available 2007-05-09T19:35:53Z
dc.date.issued 1984
dc.identifier.urihttp://hdl.handle.net/1911/15839
dc.description.abstract A commonplace symptom of vestibular endorgan damage is postural dysequilibrium. Vestibular compensation eventually restores balance to intact levels. At issue in describing the compensation process is what role other sensory input plays in balance behavior. Visual and other sensory cues may substitute for the decreased vestibular input or they may contribute to a developing reflexive mechanism that allows for balance at a range of arousal levels. To determine which of the two mechanisms underlies compensated behavior, body sway of squirrel monkeys was measured prior to and following unilateral labyrinthectomy. Visual fixation and alertness were avoided by recording sway during the animals' sleep. In three monkey subjects, body sway was analyzed from epochs of slow-wave sleep. Sway (anteroposterior and lateral), EEG, vertical eye movements, ECG, and respiration were recorded on magnetic tape; simultaneous strip-chart records also illustrated sway episodes. A characteristic sway pattern emerged following labyrinthectomy: slow deviation to the side of the lesion, followed by a rapidly corrective righting movement. This pattern resembled spontaneous eye nystagmus; therefore, the term body nystagmus was coined to refer to this behavior. Frequency of body-nystagmic beats, slow-phase body velocity (SPBV), and power-spectral density of sway were evaluated. Lateral SPBV significantly increased (p < 0.05) after unilateral lesion, then declined to intact levels. Body-nystagmic beat frequency results were inconsistent. For power-spectral density, in the lateral dimension, for both 0.00 to 0.25-Hz and 0.00 to 1.00-Hz bandwidths, energy was significantly greater (p < 0.05) three days postlabyrinthectomy than either the pre-operative condition or the compensated stage (35 days). Differences for the anteroposterior dimension were not significant. When these indices were compared with a standard measure of compensation, spontaneous eye-nystagmic velocity, lateral SPBV described the compensation trend as well or better than the oculomotor measure. These findings suggest that alternate sensory information contributes to the reestablishment of a reflexive balance mechanism. Rather than simply substitute for lost vestibular sensation, the alternate inputs integrate over the compensation period to regulate balance behavior across a range of arousal levels.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectPhysiological psychology
dc.title POSTURAL VESTIBULAR COMPENSATION IN THE SQUIRREL MONKEY (SLEEP, LABYRINTH LESION)
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Psychology
thesis.degree.discipline Social Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.citation LEVY, JOEL KUTNER. "POSTURAL VESTIBULAR COMPENSATION IN THE SQUIRREL MONKEY (SLEEP, LABYRINTH LESION)." (1984) Diss., Rice University. http://hdl.handle.net/1911/15839.


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