Regulatory changes at high altitudes in comparison with post-space-flight reactions

This report will compare results of applications of the psychophysiological method "Assessment of Autonomic Outlet Type" (AOT) in space as well as at high altitudes. The aim was to find out whether it is possible to differentiate a subject's reaction to different environments by this method (Johannes et.al. 1995). This assessment as described below was first applied to clinically well defined cohorts and to healthy subjects. By means of cluster analysis it could be demonstrated that different reaction patterns exist. These different patterns were correlated to two groups of normal controls ([I] = non-responder/voice-responder and [II] = heart-responder) and two groups of patients with different clinical diagnoses (rheumatic diseases ([III] = autonomic-responder) and [IV] = hypertensives). Based on these clinical reference data the method provides for each "new" experiment a common classification of the complex regulatory reaction pattern of the autonomic nervous system (ANS) and the Cardiovascular system (CVS) to psychological stressors by means of a discriminant function. Since August 1997 the experiment has been applied to all Russian cosmonauts continuously each month. (Johannes et.al. 1998). At the same time numerous terrestrial experiments have been running parallel for comparison with the results from space. This report will focus on a study at altitudes of 3600 m.