INDUCTION OF EXPERIMENTAL MOTION SICKNESS AND ITS EFFECT ON OKN AND OKAN ADAPTATION PROCESS

Abstract

Motion sickness was induced experimentally by pseudo-coriolis stimulation, and from changes in optokinetic nystagmus (OKN) and optokinetic afternystagmus (OKAN), the adaptation process in motion sickness was investigated.
With an increase in the number of experiments, a decreasing tendency was seen in the appearance of phase 1 of OKAN, while a significant increasing tendency was observed in phase 2. Symptons of motion sickness were alleviated with adaptation. It is considered that phase 1 of OKAN is a result of output information reflecting the indirect optokinetic passways and represents the activities of the vestibulai nuclei. With induction of motion sickness, phase 1 of OKAN was inhibited and phase 2 was increased. Therefore, it is considered that changes occurred in the vestibulai nuclei during the adaptation process of motion sickness.