[Effect of blood redistribution on illusional sensations of spatial position in weightlessness]. / Vliianie pereraspredeleniia krovi na vyrazhennost' illiuzornykh oshchushchenii prostranstvennogo polozheniia pri nevesomosti.

The study was performed onboard a specially equipped aircraft which allowed zero-g and high-g studies. Blood redistribution was produced using a tilt table (-30 degrees) and a LBNP device. Illusionary sensations were measured by a Birtok unit and subjective reports of the test subjects. In the head-down position the feeling of blood rush to the head disappeared as soon as the weightless state was reached. In most cases illusionary sensations were similar to those in the horizontal position. When exposed to LBNP tests, the subjects developed no illusionary sensations during horizontal flight and felt their upper body going upwards and legs going downwards in the weightless state. Thus, illusionary sensations of the spatial position depend at large on blood redistribution in the human body.

[Human cognitive activity during adaptation to short-term weightlessness]. / Poznavatel'naia deiatel'nost' lichnosti pri adaptatsii k kratkovremennoi nevesomosti

The differences in subjective sensations during the first exposure to short-term weightlessness are analyzed on the basis of the pattern of cognitive activity of test subjects and the scope of information they have received previously. The subjects with objective and productive types of cognitive behavior showed the most adequate and rapid adaptation to weightlessness. The subjects with a subjective and unproductive type of cognitive tactics exhibited great problems in adapting themselves to weightlessness, showing unusual psychic states like the "world peril" syndrome and psychic estrangement. Anticipation of the weightless environment based on the objective information previously obtained facilitated orientation and self-control in weightlessness.