Nishida S, Sato T
ATR Auditory and Visual Perception Research Laboratories, Kyoto, Japan.
Vision Res. 1992 Sep;32(9):1635-46. doi: 10.1016/0042-6989(92)90156-d.
Using spatially filtered random-dot kinematograms (RDK) with a 1 octave bandwidth, the duration and direction of motion aftereffect (MAE) were measured while varying step displacement, and the results were compared to those for motion direction discrimination. We found that MAE and motion discrimination show quite different dependencies on displacement. At displacements around 0.5 cycles of the lowest frequency, while motion discrimination was still almost perfect, normal MAE vanished and MAE in the same direction as that of the adapting stimuli, which we name "positive MAE", was observed. Similar results were obtained for both 1- and 2-dimensional filtered patterns. A theoretical examination based on the Fourier components of the stimuli showed that the displacement dependency of MAE is predictable in terms of adaptation of first-order detectors, but that of motion discrimination is not. The present results indicate that direction perception and MAE for bandpass RDKs are mediated at least partially by separate mechanisms, and that direction perception at larger displacements is mediated by the second-order mechanism which detects movement of contrast modulation in the image.
使用具有1倍频程带宽的空间滤波随机点运动图（RDK），在改变步长位移的同时测量运动后效（MAE）的持续时间和方向，并将结果与运动方向辨别结果进行比较。我们发现，MAE和运动辨别对位移表现出截然不同的依赖性。在最低频率约0.5个周期的位移处，虽然运动辨别仍几乎完美，但正常的MAE消失了，并且观察到与适应刺激方向相同的MAE，我们将其命名为“正向MAE”。对于一维和二维滤波模式均获得了类似结果。基于刺激的傅里叶分量进行的理论检验表明，MAE的位移依赖性根据一阶检测器的适应是可预测的，但运动辨别的位移依赖性则不然。目前的结果表明，带通RDK的方向感知和MAE至少部分由不同机制介导，并且较大位移处的方向感知由检测图像中对比度调制运动的二阶机制介导。
