Characteristics of postural self-regulation in complex spatial environments and after-effects of weightlessness

The structure of the postural-spatial activity of parachuters, high-board divers and volunteers has been studied during postural tests on sports towers and that of cosmonauts before and after space flight. The experimental results give evidence that the stabilographic pattern shows several different types which correspond to the fixed, "searching" and pliable models of postural self-regulation, regardless of professional experience. During postural tests the cosmonauts exhibited deformation of the stabilographic pattern which lost its individual features and was converted into a stable curve which was represented by unmodulated fluctuations with a period of 0.15 sec that was similar to the fixed model. Psycho-physiological mechanisms of the changes are discussed.