视动性眼震与视动性错觉关系的实验研究

Experimental studies on relationship between optokinetic nystagmus and optokinetic illusion

30名军校学员，男性，在两种指导语（请集中注意力向前看；请注视正前方的红灯）下，经受了一系列视动阶跃刺激（5、10、15、20、30、40、60、80、100、120°／s）。用磁带机记录被试的视动性服震信号，同时记录被试报告的视动性错觉。视动性服震信号在7T17信号分析仪上进行脱机采样处理，错觉用模糊集途径进行量化。结果如下：①视动性眼震快相速度、慢相速度在刺激速度为5～60°／s内随刺激速度增加而增大，在60～120°／s内达到最大值并基本维持稳定，而视动性错觉在刺激速度为5～120°／s内随刺激速度增加呈直线上升；②在5～40°／s视动刺激下，当视动性眼震被抑制时，视动性错觉量明显增大。结果提示，机动性眼震与机动性错觉无因果关系，各自表现不同的变化趋势；在低速度视动刺激下，机动性眼震减轻了视动性错觉。

TPirty students (male) from military university served as subjects. Each of them underwent a series of optokinetic step stimulation (5, 10, 15, 20, 30, 40, 60, 80, 100, 120°/s) following twokinds of introduction (1. look forward attentively/2. gaze at the red light right be fore you ). Each stimulus lasted 20 s. The optokinetic nystagmus (OKN) was recorded by tape recorder, and analysed by acomputer analysis system. Subjects were asked to report the optokinetic illusion (OKI) perceived according to a multistage eveluation scale,and the magnitude of illusion was designated using a fuzzy setmodel. The main results were as follows. (1) When speed of stimulus ranged from 5°/s to 60°/s,velocities of both slow and fast phase of OKN were increased as stimulus speed was increased,and then remained rather constant at the value when stimulus speed ranged from 60°/s to 120°/s. Meanwhile,themagnitude of OKI increased linearly with stimulus speed (5°/s to 120°/s). (2) The magnitude of OKNincreased significantly when stimulus speed ranged from 5°/s to 40°/s and OKN was inhibited followingintroduction 2. The results suggest that there is no cause-and-effect relationship between OKN and OKIwhich had been hypothesized by some authors, they revealed different trends in response to optokineticstep stimulation. However,it seems that OKN may alleviate OKI when low speed stimulus is used.