The vestibular system is responsible for sensing and controlling motion. Research in this laboratory is directed toward understanding the physiological processes that mediate vestibuloocular reflexes. These reflexes maintain the stability of images on the retina during head movements. They accomplish this task by moving the eyes through precisely the proper angle and in exactly the correct timing sequence required to compensate for the effects of head motion.

     The investigations in this laboratory have two closely related goals: 1) to define, at the level of eye movement analyses and single-unit recordings from neurons in the vestibular nerve and nuclei, the signal processing mechanisms involved in the control of rotational and translational vestibuloocular reflexes; and 2) to apply this knowledge of basic vestibular physiology to the diagnosis and treatment of balance disorders in humans.

     Our ongoing research has led to the identification of reflex dynamics that can best be understood in terms of inputs from tonic and phasic pathways. We have shown that the signals from these pathways can be selectively modified and that the physiological properties of the phasic pathway are principally responsible for the asymmetries in vestibular reflexes noted after unilateral vestibular lesions.

     Our understanding of the physiology of eye movements evoked by vestibular stimulation led to the identification of a clinical syndrome of vertigo and imbalance in patients due to a dehiscence (opening) in the bone overlying the superior semicircular canal. We developed a surgical procedure to correct this abnormality in patients with superior canal dehiscence.  We are studying the physiological effects of this lesion and the procedure used for correction of the disorder in an animal model of the syndrome.