A model of the nystagmus induced by off vertical axis rotation. 1986

T C Hain

A three-dimensional model is proposed that accounts for a number of phenomena attributed to the otoliths. It is constructed by extending and modifying a model of vestibular velocity storage. It is proposed that the otolith information about the orientation of the head to gravity changes the time constant of vestibular responses by modulating the gain of the velocity storage feedback loop. It is further proposed that the otolith signals, such as those that generate L-nystagmus (linear acceleration induced nystagmus), are partially coupled to the vestibular system via the velocity storage integrator. The combination of these two hypotheses suggests that a vestibular neural mechanism exists that performs correlation in the mathematical sense which is multiplication followed by integration. The multiplication is performed by the otolith modulation of the velocity storage feedback loop gain and the integration is performed by the velocity storage mechanism itself. Correlation allows calculation of the degree to which two signals are related and in this context provides a simple method of determining head angular velocity from the components of linear acceleration induced by off-vertical axis rotation. Correlation accounts for the otolith supplementation of the VOR and the sustained nystagmus generated by off-vertical axis rotation. The model also predicts the cross-coupling of horizontal and vertical optokinetic after nystagmus that occurs in head-lateral positions and the reported effects of tilt on vestibular responses.

UI MeSH Term Description Entries
D008433 Mathematics The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Mathematic
D008954 Models, Biological Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment. Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D009760 Nystagmus, Physiologic Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair. Nystagmus, Barany,Nystagmus, Caloric,Nystagmus, End-Position,Nystagmus, Positional,Nystagmus, Post-Rotatory,Nystagmus, Thermal,Nystagmus, Barany's,Nystagmus, Physiological,Physiologic Nystagmus,Barany Nystagmus,Barany's Nystagmus,Caloric Nystagmus,End-Position Nystagmus,Nystagmus, Baranys,Nystagmus, End Position,Nystagmus, Post Rotatory,Physiological Nystagmus,Positional Nystagmus,Post-Rotatory Nystagmus,Thermal Nystagmus
D011187 Posture The position or physical attitude of the body. Postures
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D012399 Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Clinorotation,Clinorotations,Rotations
D014785 Vision, Ocular The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain. Vision,Light Signal Transduction, Visual,Ocular Vision,Visual Light Signal Transduction,Visual Phototransduction,Visual Transduction,Phototransduction, Visual,Transduction, Visual

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