Van Opstal A J, Van Gisbergen J A
Department of Medical Physics and Biophysics, University of Nijmegen, The Netherlands.
Vision Res. 1987;27(5):731-45. doi: 10.1016/0042-6989(87)90071-x.
It has become customary to make use of so-called main sequence plots to characterize the dynamic properties of saccades. However, such a description does not account for the fact that the ratio between the accelerating and the decelerating fraction of the eye movement is not constant for all saccades. In this paper we introduce a new parameter, skewness, that characterizes this much neglected aspect of the saccade velocity profile. Human saccade data in this report demonstrate a clear relation between saccade duration (D) and skewness (S). When saccadic eye movements become extremely slow, due to fatigue or diazepam, the main sequence relation breaks down, while the S-D relation still holds. Despite large differences in amplitude, saccades of a fixed duration appear to have the same shape of velocity profile. A unifying equation relating the saccade parameters amplitude, maximum velocity and skewness, which is valid for both normal and slow saccades, is proposed.
利用所谓的主序列图来描述扫视的动态特性已成为一种惯例。然而，这样的描述并未考虑到眼球运动的加速部分与减速部分的比例并非对所有扫视都是恒定的这一事实。在本文中，我们引入了一个新参数——偏度，它表征了扫视速度剖面中这一长期被忽视的方面。本报告中的人类扫视数据表明扫视持续时间（D）与偏度（S）之间存在明显关系。当扫视眼动由于疲劳或地西泮而变得极其缓慢时，主序列关系会失效，而S-D关系仍然成立。尽管幅度差异很大，但固定持续时间的扫视似乎具有相同的速度剖面形状。我们提出了一个统一方程，该方程将扫视参数幅度、最大速度和偏度联系起来，对正常扫视和慢速扫视均有效。
