This revised continuation proposal builds upon ongoing research regarding vestibulo-ocular function in the elderly. The proposed research addresses, in part, priorities established in a Program Announcement entitled Mechanisms of Sensorimotor Adaptation issued jointly by the NIA and NASA. In particular, we will study the influence of aging on two well-described vestibulo~ocular reflex phenomena, velocity storage and visual-vestibular interaction. The latter studies will enable 1:10th eye movement assessments and a study of the influence of vestibular stimulation and visual suppression of the vestibulo-ocular reflex on cognitive processes. These studies are important because cognitive variables may play a critical role in vestibular processing, and because aging is associated with a decline in cognitive abilities, sensory capabilities, and vestibular function. Elderly subjects will be drawn from a pool of healthy community- dwelling individuals between the ages of 65 and 75. Control subjects will be healthy individuals aged 20 to 30. Vestibular stimulation will consist of earth-vertical axis and off-vertical axis rotation. Eye movements will be recorded with the magnetic scleral search coil technique and with electro-oculography. Cognitive tasks will consist of simple and complex reaction time measures using auditory cues. Subjects will perform these tasks during vestibular stimulation, visual-vestibular interaction, and several control conditions. All three aspects of the proposed study, namely, velocity storage, visual-vestibular interaction, and the influence of vestibular stimulation and visual suppression of the vestibulo-ocular reflex on cognitive performance depend upon multi-neuronal pathways and will allow an improved understanding of how aging affects the balance system, specifically, the processing of vestibular signals by the CNS.
Showing the most recent 10 out of 27 publications
