Segal B N, Katsarkas A
Department of Otolaryngology, Sir Mortimer B. Davis - Jewish General Hospital, Montréal, Québec, Canada.
Exp Brain Res. 1988;70(1):26-32. doi: 10.1007/BF00271843.
Vestibular function was examined during passive head movements having profiles that approximated low-to-intermediate range of natural self-generated movements (10-220 degrees/s peak velocity, about 0.5 s duration). A seated subject looked at a point target on the wall, the lights were extinguished and the chair was briefly turned while the subject tried to "look" at the just-viewed point. The chair was stopped, the lights were turned on again and the target was re-fixated, if necessary. Ocular stabilization was characterized (1) by "net stabilization" that was due to the combined effects of both slow-phase and rapid (saccadic or quick-phase) eye movements, (2) by "cumulative-slow-phase stabilization" that was due to slow-phase eye movements, and (3) by "cumulative-saccadic stabilization" that was due to effects of all rapid eye movements. It was found that both slow-phase and saccadic eye movements tended to keep the eyes on the actual unseen target. During repeatedly applied head movements, net and cumulative-slow-phase stabilization tended to be almost perfect. However, the average magnitude of the error in net stabilization (i.e., deviation from perfection) was always less than the corresponding error in slow-phase stabilization. This occurred because in a given turn, saccadic movements tended to supplement deficient slow-phase movements and to decrement excessive slow-phases. In 4 of 5 subjects, cumulative-saccadic stabilization tended to equal the error in cumulative-slow-phase stabilization. All results were unaffected by head velocities up to +/- 220 degrees/s. It was concluded that these saccades tended to stabilize gaze (eye + head) in space during head movements in total darkness.
在前庭功能测试中，被动头部运动的速度范围模拟自然产生的低到中等速度运动（峰值速度为10 - 220度/秒，持续时间约0.5秒）。受试者坐在椅子上，注视墙上的一个点目标，灯光熄灭，椅子短暂转动，同时受试者试图“注视”刚才看到的点。椅子停止转动后，再次打开灯光，必要时重新注视目标。眼动稳定通过以下方式进行表征：（1）“净稳定”，它是慢相和快速（扫视或快相）眼动共同作用的结果；（2）“累积慢相稳定”，它仅由慢相眼动引起；（3）“累积扫视稳定”，它是所有快速眼动作用的结果。研究发现，慢相和扫视眼动都倾向于使眼睛保持在实际看不到的目标上。在反复进行头部运动时，净稳定和累积慢相稳定几乎趋于完美。然而，净稳定的平均误差幅度（即与完美状态的偏差）总是小于慢相稳定的相应误差。这是因为在给定的转动中，扫视运动倾向于补充不足的慢相运动并减少过度的慢相运动。在5名受试者中的4名中，累积扫视稳定倾向于与累积慢相稳定的误差相等。所有结果在头部速度高达±220度/秒时均不受影响。研究得出结论，在完全黑暗中头部运动期间，这些扫视运动倾向于稳定空间中的注视（眼睛 + 头部）。
