The Changes Of Coriolis Illusion Under Different Acceleration Stimulation And Preliminary Studies On The Mechanism Of Coriolis Illusion Adaptation

When an individual tilts his head while rotating, he is exposed to an unusual pattern of vestibular stimulation caused by Coriolis acceleration. Such stimulation leads to a perceptual misinterpretation of the head movement which is called Coriolis illusion (CI). It is one of the most common illusions in flight among the pilots of fighter planes. American researchers investigated 105 pilots of fighter planes, according to the survey, 50 per cent pilots had experienced CI in flight. Our survey in 1999 is analogous to theirs. In high-performance aircraft the pilots are vulnerable to CI because of some of the aircrafts' characteristics, which include high sustained +Gz(HSG) acceleration, high rate of onset and high angular acceleration etc. So it has all the while been attached much importance to the studies on the mechanism of CI and the preventing and overcoming method of CI by the researchers in aviation medicine field.Electronystagmography(ENG) is usually used as the objective index to study CI. But it is not clear about the influence of different Coriolis acceleration levels on human CI and concomitant nystagmus as well as the correlation between CI and ENG parameters.As high maneuverability aircraft is concerned, angular acceleration and linear acceleration coexist in flight. It has been found that CI is more obvious when Z axial linear acceleration acts on it. But it has not been studied on the effect of different axis(xN y axis) linear acceleration on CI.It has been studied on the mechanism of CI from the view of the interaction among semicircular canal, otolith organ and proprioceptor. But the studies on neurophysiology mechanism are not enough. Some scholars think that a great number of 5-hydroxytryptamine (5-HT) accumulating in nerve center ,which induced by protein disturbance of metabolism resulting from acceleration stimulation, resulted in vestibular illusions. But it isn't clear that whether Coriolis acceleration can increase of5-HT contents in nerve center and whether CI is related to it.Up to now physiological and psychological training of CI experiencing has been mainly used to prevent and overcome CI. On one hand, it can make the pilots know CI well. On the other hand, it also can induce CI adaptation . It has been confirmed by many experiments. But it has been known little about neurophysological mechanism of CI adaptation counteracting CI.The study presented here tried to investigate the problems mentioned above .The main results of this work are as follows:1. The influence of Coriolis acceleration level on human oculomoor and perceptual responsesTo investigate the influence of different Coriolis acceleration levels (0.329 cm/s2 > 0.493 cm/s2 ^ 0.658 cm/s2) on human subjective sensation and nystagmus. Basic parameters including the pattern, the duration and the intensity of CI as well as mean slow phase velocity (MSPV), beat, time constant of slow phase velocity decay and duration of horizontal and vertical ENG, were recorded. We found that different level Coriolis acceleration stimulation had no significant influence on the duration of the illusion but had some influence on the pattern of the illusion, the intensity of CI increased with the levels of Coriolis acceleration stimulation, and no significant difference was observed on nystagmus beats, peak slow phase velocity, mean slow phase velocity, time constant of slow phase velocity decay, duration of ENG among different Coriolis acceleration stimulation, but the direction of ENG is consistent with the pattern of CI. The results suggested that there lies certain regularity in the pattern of CI and the regularity depends on definite magnitude of Coriolis stimulation; the duration and the intensity of CI are positive related to the magnitude of Coriolis stimulation; the parameters of ENG accompanying CI can't be used as the objective indication of CI.2. The influence of different axis linear acceleration on Coriolis illusionTo observe the effect of different axis(x x y axis) linear acceleration on Coriolis illusion...