HUMAN PERCEPTION OF BODY LONGITUDINAL AXIS IN PARABOLIC FLIGHT

摘要

Gravity provides vital inputs to the human sensory and balance system. The "Human Perception of Body Longitudinal Axis"-experiment investigated the ability of human subjects to accurately locate their long body axis (axis running from head to toes) while free-floating in microgravity. The effects of tactile pressure applied on the chest and back upon the accuracy of this perception have also been tested. The experiment was performed in Bordeaux, France during the 6~(th) ESA Student Parabolic Flight Campaign, July 23-31, 2003. Subjects were tested in-flight, as well as on ground in Earth's gravity before and after flight to provide baseline measurements. The goal was to identify those tactile inputs that provide the subject with the greatest clues for the location of the long body axis. The subjects wore a mask and were in total darkness. They had to align two luminous lines inside the mask in two different vertical planes: frontal (right/left) and sagittal (forward/backward) planes. Results showed that the subjects' ability to locate their long body axis was considerably impaired in microgravity, especially in the sagittal plane, but that pressure on the chest or on the back restored this ability.