Otolith function as determined by body orientation in a human centrifuge

In an attempt to better understand the otolith organs' contribution to postural control and their involvement with antigravity muscle spindle gain, we propose employing a human centrifuge to simulate prolonged exposure to free-fall and +G environments while quantifying each volunteer's vestibulospinal reflex (VSR) utilizing vestibular evoked myogenic potentials (VEMP). The two testing environments will stimulate the saccule organ in opposing fashions, acting inferiorly and superiorly respectively, either hyperpolarizing or depolarizing the organ's hair cells. The findings of this study may lead to new techniques that assist with motor control in cerebral palsy patients and astronauts returning from spaceflight.