Spatial Orientation, Navigation, and Neuropsychologic Function in Patients With Vestibular Implant

The vestibular system, located in the inner ear, provides information to the brain information about how head acceleration and orientation relative to gravity. Damage to the vestibular system is usually permanent and can contribute to a lower quality of life. The goal of this research is to to examine how vestibular implants (VI) may improve performance of cognitive tasks in patients with severe vestibular damage. These higher-level cognitive behaviors include (1) orientation relative to gravity, (2) navigation, and (3) neuropsychologic function. VI patients will be tested in these three cognitive domains across study sessions: pre-stimulation (VI implanted but stimulation OFF), following chronic stimulation (12 days, VI-ON), and then again 1 month later with the VI turned off. There will be both "true" stimulation experiments during which the VI will provide motion-modulated stimulation and also "placebo" stimulation (no motion cues, tonic stimulus). The order of these experiments will be randomized and separated by 3 months. Researchers will compare VI data in the three cognitive domains (spatial orientation, navigation, \& neuropsychologic function) with control data from non-implanted bilateral vestibular loss (BVL) and unilateral vestibular loss (UVL) patients and normal subjects.