Sensory deprivation, weightlessness and anti-gravity mechanisms. The problem of fetal adaptation to a floating existence.

In aerospace medicine, attention focuses on the effects of the loss of gravitational pull on the body. The more fundamental question involved is the basic physiology of anti-gravity mechanisms upon the body. From this viewpoint, the entire spectrum of the consequences of weightlessness may be seen. Then evidence affirming the broad concept of sensory deprivation in general, and anti-gravity deprivation in particular, may be looked for. The principle is to go from the general to the specific rather than from specifics to generalities. In their book, Xybernetics of ~atural Systems, 14 D. and I<. Stanley-Jones establish a case for the concept that physiological systems which are in a state of dynamic equilibrium, as are all living things, are under the control of built-in mechanisms which 'hold them under control. This is true of homeostasis and postural mechanisms. "The central nervous system is dependent for its functioning upon the ceaseless influx of neural permeability waves created by the activity of the sense organs. ''14 This, then, is the source of neural dynamic energy. In the case of the nervous system, mammals