Fast component threshold for vestibular nystagmus in the rabbit

Lau, Clifford G. Y.; Honrubia, Vicente

doi:10.1007/bf00611931

Cited by 5 publications

(3 citation statements)

References 15 publications

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“…The QP amplitude is also dependent on both the QP start position and SP velocity. Similar relationships have been observed in the threshold for triggering the QP of vestibular nystagmus in humans (Lau, Honrubia, & Baloh, 1978) and rabbits (Lau & Honrubia, 1986). This implies that these relationships have biological relevance in other species and even other forms of nystagmus, and future studies might investigate how the model parameters change between foveate and afoveate species or between optokinetic and vestibular nystagmus.…”

Section: Discussionsupporting

confidence: 55%

Human optokinetic nystagmus: A stochastic analysis

Waddington

Harris

2012

Journal of Vision

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Optokinetic nystagmus (OKN) is a fundamental gaze-stabilizing response found in almost all vertebrates, in which eye movements attempt to compensate for the optic flow caused by self-motion. It is an alternating sequence of slow compensatory eye movements made in the direction of stimulus motion and fast eye movements made predominantly in the opposite direction. The timing and amplitude of these slow phases (SPs) and quick phases (QPs) are remarkably variable, and the cause of this variability is poorly understood. In this study principal components analysis was performed on OKN data to illustrate that the variability in correlation matrices across individuals and recording sessions reflected changes in the noise in the system while the linear relationships between variables remained predominantly the same. Three components were found that could explain the variance in OKN data, and only variables from within a single cycle contributed highly to any given component. A linear stochastic model of OKN was developed based on these results that describes OKN as a triple first order Markov process, with three sources of noise affecting SP velocity, the QP trigger, and QP amplitude. This model was used to predict the degree of signal dependent noise in the system, the duration of the transient state of SP velocity, and an apparent undershoot bias to the QP target location.

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Section: Discussionsupporting

confidence: 55%

Human optokinetic nystagmus: A stochastic analysis

Waddington

Harris

2012

Journal of Vision

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“…There is a wide range of neurons, and each operates with different characteristics. Their frequency sensitivity varies, and each neuron functions as a tuned filter for specific head motions 3‐40 (i.e., frequency selective). It has been suggested tht the heterogeneity of responses represent developmental adaptive strategies that fulfill the biologic needs of vestibulospinal reflexes and VORs to achieve their behavioral goals 41 .…”

Section: Modern Approach To Evaluation Of Vestibular Functionmentioning

confidence: 99%

“…In all varieties of nystagmus, the fast component acts in anticipation to compensate for a positional sense for the gaze shift produced by the slow component, whereas the slow component is compensatory in the velocity domain: The production of the fast component is far from being random. It has been shown that the initiation of the fast component can be predicted on the basis of slow‐component position and velocity in animals and human beings 26 , 27 . Very specific changes in the fast‐component characteristics have been observed in a variety of patients 1 under different testing conditions 2 .…”

Section: Technologic Developmentsmentioning

confidence: 99%

Contemporary vestibular function testing: Accomplishments and future perspectives

Honrubia

1995

Otolaryngol.--head neck surg.

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The development of a standard test battery for the evaluation of vestibular function required a variety of preliminary investigations about the technical and physiologic foundations of the tests. The most important technologic development was the creation of computerized methods, including hardware and software capabilities. The designs of tests were based on physiologic and diagnostic considerations, as demonstrated in experiments on normal subjects and patients. Although time tested and sound, the available test battery satisfies only a limited number of requirements for comprehensive evaluation of vestibular function. This article describes the list of accomplishments, the state of the present limitations, and the needs for the future.

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Behavioural characteristics of the quick phase of vestibular nystagmus before and after unilateral labyrinthectomy in guinea pig

et al. 2003

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The aim of this paper was to characterise the conditions under which the quick phase of vestibular nystagmus is generated in response to sinusoidal horizontal angular accelerations in guinea pig and to determine whether the characteristics of the quick phase are altered following unilateral vestibular deafferentation (UVD). In experiment 1, the quick-phase response to 2-Hz sinusoidal stimuli with different peak head velocities was measured before and after UVD. In experiment 2, lower-frequency stimuli with a fixed amplitude (+/-20 degrees ) were used to measure the eye-movement response. In experiment 1, at 2 Hz, the most noticeable difference between UVD animals and normal animals was a reduction in the number of quick phases generated, particularly when rotating towards the lesioned side: the onset of the quick phase was delayed and occurred at a lower value of peak head velocity compared to normals. However, both these measures probably reflect the depressed slow-phase eye-velocity gain rather than a change in the quick-phase mechanism itself, because if a quick phase was generated there was no difference between UVDs and normals on a variety of measures (duration, position, peak eye velocity) for a 2-Hz stimulus. For both UVD and normal animals there did appear to be a position threshold for the onset of a quick-phase eye movement (approximately +/-7.5 degrees ), although it should be noted that the threshold is not an absolute value. In experiment 2, with lower-frequency stimuli, the characteristics of the quick phase itself were altered in UVD animals. At these lower accelerations, although the head velocity and average eye position for the onset of the quick phase did not differ between UVD and normal animals, there were significant differences between UVD and normal animals in the number of quick phases generated (fewer), the duration of the quick phase (longer) and the peak eye velocity of the quick phase (slower). For lower-frequency stimuli there was no evidence of a specific eye-position threshold for the generation of a quick phase, although the position at which a quick phase occurred rarely exceeded the +/-7.5 degrees value obtained in experiment 1. The behavioural data were used to produce a biologically based neural-network simulation of both the slow- and quick-phase components of the vestibulo-ocular reflex, the results of which are presented in a companion paper.

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Fast component threshold for vestibular nystagmus in the rabbit

Cited by 5 publications

References 15 publications

Human optokinetic nystagmus: A stochastic analysis

Human optokinetic nystagmus: A stochastic analysis

Contemporary vestibular function testing: Accomplishments and future perspectives

Behavioural characteristics of the quick phase of vestibular nystagmus before and after unilateral labyrinthectomy in guinea pig

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