Sadeghpour Shirin, Otero-Millan Jorge
Johns Hopkins University, Baltimore, MD, USA.
J Eye Mov Res. 2020 Oct 20;13(5). doi: 10.16910/jemr.13.5.5.
While many studies have characterized the eye movements during visual fixation, includ-ing microsaccades, in most cases only horizontal and vertical components have been rec-orded and analyzed. Thus, little is known about the torsional component of microsaccades. We took advantage of a newly developed software and hardware to record eye movements around the three axes of rotation during fixation and torsional optokinetic stimulus. We found that the average amplitude of the torsional component of microsaccades during fixation was 0.34 ± 0.07 degrees with velocities following a main sequence with a slope comparable to the horizontal and vertical components. We also found the size of the tor-sional displacement during microsaccades was correlated with the horizontal but not the vertical component. In the presence of an optokinetic stimulus a nystagmus was induced producing a more frequent and larger torsional quick phases compared to microsaccades produced during fixation with a stationary stimulus. The torsional component and the vertical vergence component of quick phases grew larger with higher velocities. Addition-ally, our results validate and show the feasibility of recording torsional eye movements using video eye tracking in a desktop mounted setup.
虽然许多研究已经对视觉注视期间的眼球运动进行了特征描述，包括微扫视，但在大多数情况下，仅记录和分析了水平和垂直分量。因此，对于微扫视的扭转分量知之甚少。我们利用新开发的软件和硬件，记录了注视期间以及扭转性视动刺激期间围绕三个旋转轴的眼球运动。我们发现，注视期间微扫视扭转分量的平均幅度为0.34±0.07度，其速度遵循主序列，斜率与水平和垂直分量相当。我们还发现，微扫视期间扭转位移的大小与水平分量相关，而与垂直分量无关。在存在视动刺激的情况下，会诱发眼球震颤，与固定刺激下注视期间产生的微扫视相比，产生更频繁、更大的扭转性快相。快相的扭转分量和垂直聚散分量随着速度的增加而增大。此外，我们的结果验证并展示了在台式安装设置中使用视频眼动追踪记录扭转性眼球运动的可行性。
