Grüsser O J, Pause M, Schreiter U
Exp Brain Res. 1979 May 2;35(3):519-26. doi: 10.1007/BF00236769.
Sigma-optokinetic nystagmus (sigma-OKN) can be elicited in awake Java monkeys (Macaca fascicularis) when stationary periodic visual patterns (grid of black white stripes, row of equally spaced dots) are illuminated stroboscopically. Three methods were found to be useful in inducing the sigma-OKN: postrotatory nystagmus, optokinetic afternystagmus (OKAN) following normal OKN and a gradual transition from phi-movement (phi-OKN) to sigma-OKN. The properties found for sigma-OKN in man are also present in monkeys with the one exception that monkeys have a long-lasting sigma-OKAN in darkness which is not present in man. The average angular speed Ve of sigma-OKN slow phases was related to the flash frequency fs and the spatial period Ps of the stripe pattern according to the following equation: Ve = k.Ps . fs [degrees . s-1] The constant k was 1 or close to 1.
当静止的周期性视觉模式（黑白条纹网格、等间距点行）以频闪方式照明时，可在清醒的爪哇猴（食蟹猴）中诱发西格玛视动性眼球震颤（sigma-OKN）。发现有三种方法可用于诱发sigma-OKN：旋转后眼球震颤、正常OKN后的视动性继后眼球震颤（OKAN）以及从φ运动（phi-OKN）到sigma-OKN的逐渐转变。在人类中发现的sigma-OKN的特性在猴子中也存在，唯一的例外是猴子在黑暗中有持久的sigma-OKAN，而人类不存在。sigma-OKN慢相的平均角速度Ve与闪光频率fs和条纹图案的空间周期Ps符合以下方程：Ve = k.Ps . fs [度·秒-1]。常数k为1或接近1。
