Diamond S G, Markham C H
Department of Neurology, UCLA School of Medicine 90024-1769.
Aviat Space Environ Med. 1991 Mar;62(3):201-5.
The hypothesis of asymmetric otolith function asserts that physiological or anatomical differences in the two sides of the bilateral gravity-sensing otolith apparatus of the inner ear may be well compensated on Earth, but when exposed to novel gravitational states, the prior compensatory stratagems may be ineffective, leading to unstable vestibular responses and causing the phenomenon of space motion sickness. To investigate this hypothesis, spontaneous eye torsion, a reflex governed by the otolith organs, was examined in the upright position during the hypo- and hypergravity of parabolic flight aboard NASA's KC-135 aircraft in nine former astronauts whose history of space motion sickness was revealed after data analysis had been completed. Results showed that astronauts who had been sick in space had significantly higher scores of disconjugate eye torsion in parabolic flight, and that their responses were consistently different in 1.8 G relative to 0 G compared to astronauts who had not been sick in space. In 1 G, there were no differences in disconjugate eye torsion between the subjects. The results support the asymmetry hypothesis and offer a possible predictive test of space motion sickness.
不对称耳石功能假说认为，内耳双侧重力感应耳石器官两侧的生理或解剖差异在地球上可能得到很好的补偿，但当暴露于新的重力状态时，先前的补偿策略可能无效，导致前庭反应不稳定并引发空间运动病现象。为了研究这一假说，在抛物线飞行的失重和超重阶段，对9名前宇航员在直立姿势下由耳石器官控制的自发眼扭转反射进行了检查。这些宇航员的太空运动病史在数据分析完成后才被揭示。结果显示，在太空中患过病的宇航员在抛物线飞行中眼扭转失调得分显著更高，并且与未在太空中患病的宇航员相比，他们在1.8G相对于0G时的反应始终不同。在1G时，受试者之间的眼扭转失调没有差异。这些结果支持了不对称假说，并为空间运动病提供了一种可能的预测测试。
