IMAGINARY GAZE EFFECTS ON EYE-MOVEMENTS INDUCED BY LINEAR ACCELERATION - INVOLVEMENT OF VESTIBULAR INDUCED SMOOTH-PURSUIT EYE-MOVEMENT

We investigated smooth eye movements elicited i) by linear acceleratio n in a space-fixed imaginary gaze condition (smooth component of eye m ovement induced by linear motion: LSEM) and ii) during acoustic pursui t of a moving sound source (smooth component of eye movement induced b y acoustic pursuit of a sound source: SSPEM). The two conditions were examined using the same test subjects. LSEM and SSPEM performance was found to he positively correlated across the subject population. From the comparison of LSEM and SSPEM we propose the following hypothesis: LSEM consists not only of a pure translational vestibular-ocular refle x (tVOR) component but also of a component based on the perception of otolithic information. Accordingly, this second component is instrumen tal in the pursuit of an imaginary visual target during linear self-mo tion.