Harris L R, Lewis T L, Maurer D
Department of Psychology, York University, Toronto, Ontario, Canada.
Vis Neurosci. 1993 Mar-Apr;10(2):247-59. doi: 10.1017/s0952523800003655.
We evaluated the subcortical pathways' contribution to human adults' horizontal OKN by using a method similar to that used previously with cats (Harris & Smith, 1990; Smith & Harris, 1991). Five normal adults viewed plaids composed of two drifting sinusoidal gratings arranged such that their individual directions of drift were 60 deg or more from the direction of coherent motion of the overall pattern. Physiological evidence indicates that under monocular viewing, nasalward coherent motion gives advantage to any crossed subcortical contribution while temporalward coherent motion minimizes it. We recorded horizontal eye movement by infrared reflection and asked subjects to report the perceived direction of motion. During both binocular and monocular viewing, the direction of the slow phase of OKN fell closer to the direction of coherent movement than to that of the oriented components. Monocular viewing produced no nasal-temporal asymmetries in the influence of coherent motion on the direction of OKN. This suggests that in humans the influence of coherent motion is mediated primarily by cortical mechanisms and, unlike in cats, with little or no involvement of subcortical mechanisms in the generation of horizontal OKN.
我们采用了一种与先前用于猫的方法类似的方法(哈里斯和史密斯,1990年;史密斯和哈里斯,1991年),评估了皮质下通路对成年人类水平视动性眼震(OKN)的贡献。五名正常成年人观看了由两个漂移的正弦光栅组成的方格图案,其排列方式使得它们各自的漂移方向与整体图案的连贯运动方向相差60度或更多。生理学证据表明,在单眼观察下,向鼻侧的连贯运动有利于任何交叉的皮质下贡献,而向颞侧的连贯运动则使其最小化。我们通过红外反射记录水平眼动,并要求受试者报告感知到的运动方向。在双眼和单眼观察期间,OKN慢相的方向更接近连贯运动的方向,而不是定向成分的方向。单眼观察在连贯运动对OKN方向的影响上没有产生鼻颞不对称。这表明在人类中,连贯运动的影响主要由皮质机制介导,与猫不同的是,在水平OKN的产生中,皮质下机制很少或没有参与。