视动刺激和头动对运动病的交互作用及其机制分析

Interaction of Optokinetic stimuli and Head Movements on Motion Sickness and Analysis of its Mechanism

本研究观察了26名被试者在偏转、滚转和翻转视动刺激及其与相应头动的交互作用下诱发的运动病严重程度,并分析了相互作用机制。结果发现,翻转视动刺激诱发的运动病最重,偏转视动刺激诱发的最轻,滚转视动刺激诱发的居中;但偏转视动错觉最强,翻转视动错觉最弱,滚转视动错觉居中。这是由于耳石器官对三种视动刺激的限制作用不同及造成的矛盾冲突大小不同的结果。偏转视动刺激与翻转或滚转头动的组合是一种强组合,显著地加重运动病症状;翻转视动刺激与翻转、滚转或偏转头动的组合,以及同轴的滚转视动否则激与滚转头动的组合是一种弱组合,均显著地减轻运动病症状。在强组合中伪coriolis效应起作用,视前庭矛盾冲突大,对运动病激厉作用强;弱组合中伪Coriolis效应不起作用,矛盾冲突小,激厉作用弱。前者,头动是刺激因素;后者,头动是调节因素。

Sixteen male and ten female subjects were tested in a rotating sphere at speed of 7.5 r/min and exposed to optokinetic stimulation (OS) of pitch, roll or yaw. Yaw vection induced by yaw-OS was the strongest illusory sensation of self-rotation, followed by roll vection induced by roll-OS and then pitch vection by pitch-OS. This was principally because of the restraint of utricle otoliths to roll vection and the restraint of utricle and saccule otoliths to pitch vection. The different restraint of otoliths organs implied the different conflict of otoliths information with visual signals under different OS. Therefore, pitch-OS was the most stressful in inducing motion sickness (MS), roll-OS the second and Yaw-OS the third, according to the conflict theory about MS. The strong combinations of OS and head movenents (HM), for example, the combinations of yaw-OS with pitch-HM, or yaw-OS with roll-HM, significantly enhanced MS, while the weak combinations, such as the combinations of pitch-OS with pitch-HM, roll-HM or yaw-HM,and roll-OS with roll-HM, significantly suppressed MS. In the strong combinations, pseudo-Coriolis effect, which caused severe conflict between visual-vestibular systems, was powerful and head movement played a provocative role in MS. In the weak combinations, pseudo-Coriolis effect did not work and conflict between visual-vestibular systems became weak while head movement played a modulating role in the induction of MS.