METABOLIC AND ELECTRICAL ACTIVITIES OF THE BRAIN DURING 21-DAY DRY IMMERSION
Dynamics of the CNS neurophysiological processes in 10 male volunteers during the 21-day DI study was tracked by way of plural brain investigations and tests including the concurrent EEG recording, measurements of the permanent potential levels (PPL) and the simple oculomotor reaction time (OMRT), and the Luscher color test. On DI day-7, a buildup of the CNS tension was evidenced by growth of the EEG β1 relative power and PPL values. On day-14, the majority of the volunteers had been adapted to DI demonstrating prevalence of EEG pattern type-I and decreased PPL values. On day-21, data of the investigations reflected CNS excitation due to, probably, the upcoming end of the study. Initial levels of anxiety varied from low to mean. On DI days 14 and 21, mean anxiety rose to the high level; based on OMRT, the CNS state in volunteers with mean anxiety showed instability in different DI periods. Volunteers with the initially low anxiety remained unworried in the course of immersion which was favorable to their mental performance. Baseline neurophysiological investigations help detect people with unstable CNS conditions that may impact mental performance and, therefore, can be useful in selection of candidates for long-duration space missions.