Miura Kenichiro, Matsuura Kiyoto, Taki Masakatsu, Tabata Hiromitsu, Inaba Naoko, Kawano Kenji, Miles Frederick A
Horizontal Medical Research Organization, Graduate School of Medicine, Kyoto University, Japan.
Vision Res. 2006 Mar;46(6-7):869-78. doi: 10.1016/j.visres.2005.10.021. Epub 2005 Dec 13.
Psychophysical evidence indicates that visual motion can be sensed by low-level (energy-based) and high-level (feature-based) mechanisms. The present experiments were undertaken to determine which of these mechanisms mediates the initial ocular following response (OFR) that can be elicited at ultra-short latencies by sudden motion of large-field images. We used the methodology of Sheliga, Chen, Fitzgibbon, and Miles (Initial ocular following in humans: A response to first-order motion energy. Vision Research, 2005a), who studied the initial OFRs of humans, to study the initial OFRs of monkeys. Accordingly, we applied horizontal motion to: (1) vertical square-wave gratings lacking the fundamental ("missing fundamental stimulus") and (2) vertical grating patterns consisting of the sum of two sinusoids of frequency 3f and 4f, which created a repeating pattern with beat frequency, f. Both visual stimuli share a critical property: when subject to 1/4-wavelength steps, their overall pattern (feature) shifts in the direction of the steps, whereas their major Fourier component shifts in the reverse direction (because of spatial aliasing). We found that the initial OFRs of monkeys to these stimuli, like those of humans, were always in the opposite direction to the 1/4-wavelength shifts, i.e., in the direction of the major Fourier component, consistent with detection by (low-level) oriented spatio-temporal filters as in the well-known energy model of motion analysis. Our data indicate that the motion detectors mediating the initial OFR have quantitatively similar properties in monkeys and humans, suggesting that monkeys provide a good animal model for the human OFR.
心理物理学证据表明，视觉运动可通过低层次（基于能量）和高层次（基于特征）机制来感知。本实验旨在确定这些机制中哪一种介导了最初的眼跟踪反应（OFR），这种反应可由大视野图像的突然运动在超短潜伏期引发。我们采用了谢利加、陈、菲茨吉本和迈尔斯（《人类的最初眼跟踪：对一阶运动能量的反应》，《视觉研究》，2005年a期）研究人类最初眼跟踪反应的方法来研究猴子的最初眼跟踪反应。因此，我们对以下两种情况施加水平运动：（1）缺少基频的垂直方波光栅（“缺失基频刺激”），以及（2）由频率为3f和4f的两个正弦波之和组成的垂直光栅图案，该图案产生了拍频为f的重复图案。这两种视觉刺激都具有一个关键特性：当经历1/4波长步长时，它们的整体图案（特征）会沿步长方向移动，而其主要傅里叶分量会沿相反方向移动（由于空间混叠）。我们发现，猴子对这些刺激的最初眼跟踪反应与人类一样，总是与1/4波长移动方向相反，即沿主要傅里叶分量的方向，这与在著名的运动分析能量模型中由（低层次）定向时空滤波器进行检测一致。我们的数据表明，介导最初眼跟踪反应的运动探测器在猴子和人类中具有数量上相似的特性，这表明猴子为人类眼跟踪反应提供了一个良好的动物模型。
