Suppression video head impulse testing was recently introduced as a simple, non-invasive method of assessing inner ear balance function. During testing, the patient wears a pair of video-recording goggles while staring at a laser target projected from the goggles onto a wall. Quick head turns generate eye movements that are recorded by the goggles to determine the level of function. This study will investigate the effects of attention and cognition on eye movement responses in patients with cognitive, neurological and balance impairment. Knowledge of how the test is affected by different subject factors is important for the interpretation of results.