Mather G
Vision Res. 1984;24(10):1399-405. doi: 10.1016/0042-6989(84)90195-0.
Two alternative schemes have been proposed for coding the local direction of stimulus motion in the visual image. The "sequence discrimination" scheme (e.g. Barlow H.B. and Levick W. R., J. Physiol., Lond. 178, 477-504, 1965) uses sequential change in stimulus position over time to infer movement direction; the "spatiotemporal derivative" scheme (Marr D.M. and Ullman S., Proc. R. Soc. Lond. B211, 151-180, 1981) uses change in stimulus luminance over space and time at just one position to infer movement direction. To test these models, subjects were shown stimuli which contained combinations of stationary vertical edges and changing luminances over time. They consistently reported either leftward or rightward motion, even though no sequential change in edge location took place. Perceived directions agreed with the predictions of the spatiotemporal derivative scheme. Alternative explanations for the results based on changes in apparent edge location could not account for the data. Previous reports of apparent motion during changes in stimulus luminance are also consistent with the scheme.
针对视觉图像中刺激运动的局部方向编码，已提出了两种替代方案。“序列辨别”方案（例如，巴洛H.B.和利维克W.R.，《生理学杂志》，伦敦，178卷，477 - 504页，1965年）利用刺激位置随时间的顺序变化来推断运动方向；“时空导数”方案（马尔D.M.和乌尔曼S.，《伦敦皇家学会学报》B211卷，151 - 180页，1981年）仅在一个位置利用刺激亮度随空间和时间的变化来推断运动方向。为了测试这些模型，向受试者展示了包含静止垂直边缘和随时间变化亮度组合的刺激。即使边缘位置没有顺序变化，他们仍一致报告向左或向右的运动。感知到的方向与时空导数方案的预测一致。基于表观边缘位置变化对结果的其他解释无法解释这些数据。先前关于刺激亮度变化期间表观运动的报告也与该方案一致。
