[Awareness of the subjective vertical in weightlessness (results of Austrian-Russian experiment Optovert performed within the framework of the program Austromir, part III)].

Data about intersensory interactions and adaptations, dynamics of the adaptive shifts were obtained in short- and long-term space missions basing on the indices of the subjective optical vertical awareness evaluated in experiment "OPTOVERT" with the use of dedicated ingenious techniques and hard- and software. As was shown, the function of subjective optical vertical (SOV) awareness remained unaltered in microgravity; however, in the period of adaptation there was a significant growth of error in SOV awareness in the darkness, and against the vertical optokinetic stimulation. In prolonged microgravity SOV error returns to the norm both in the darkness and during stimulation while arising asymmetry differs from background in magnitude and directivity, exceeds the physiological norm and sustains throughout a mission.

[Spontaneous and visually-induced oculomotor reactions in microgravity (Results of Austrian-Russian Experiment "Optovert" performed within the frame of program "Austromir", part II)].

Results of investigation of spontaneous and induced by vertical linear and sinusoid optokinetic stimulation oculomotor reactions in short- and long-term space missions are reported. Adaptation to microgravity was shown to be associated with rearrangement in sensory interactions even on a background of good subjective well-being and absence of abnormal autonomous nervous reactions. In the early period of adaptation to microgravity records were made of modified spontaneous oculomotor activity (spontaneous vertical nystagmus) and vertical optokinetic nystagmus (VOKN) including alterations in amplitude and VOKN amplification coefficient.