Relevance. It is one of very important tasks of modern neuroscience to investigate the psychological and psychophysiological mechanisms of body orientation processes. Particularly due to the growth in use of visualization and simulation technologies (virtual reality, projection displays, aircraft simulators). The application of such systems is often associated with mismatch between different sensory signals. One of the phenomena resulting from this mismatch is the self-motion illusion – the perception of own movement by a motionless person observing a moving visual stimulus occupying a large part of field of view.

Objective. Investigation the role of optokinetic nystagmus in self-motion illusion. The virtual optokinetic drum rotating at 30, 45 and 60 deg/s was used as a stimulus. The drum was presented using CAVE virtual reality system. 17 healthy participants took part in the experiment. The slow phases of nystagmus during self-motion illusion perception were analyzed. 

Results. The more the drum rotation speed, the more the illusion intensity and slow phases duration. Also the disturbances in slow phase realization led to increase the illusion intensity. The restoration of nystagmus reduced the illusion. Thus it was found that optokinetic nystagmus is a component of a human space orientation system and the nystagmus also adjusts the illusion perception. The effectiveness of application of CAVE virtual reality system in complicated cognitive processes investigation was proved.