Abstract
Gravity is such a constant environmental influence on spatial orientation and movement that the active CNS adaptations to it are easily underestimated, and they are best revealed when the background force conditions are altered. This chapter reviews illusions and movement errors that occur in hypo- and hypergravity environments as well as in a rotating artificial gravity environment where additional novel dynamic Coriolis forces are present. The phenomena reviewed reveal the importance of tactile cues from contact forces on the body surface and proprioceptive cues from muscle spindle and tendon receptor loading that are usually perceptually inaccessible, in addition to the vestibular cues that traditionally receive consideration. The role of these touch, pressure, and kinesthetic cues in visual and auditory localization, body schema, motor coordination, and learning of simple reaching movements to complex postural balancing are discussed.