Assimilation-type and contrast-type bias of motion induced by the surround in a random-dot display: Evidence for center-surround antagonism
Assimilation-type and contrast-type bias of motion induced by the surround in a random-dot display: Evidence for center-surround antagonism
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DOI：
10.1016/0042-6989(96)00094-6
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发表时间：
1996-11-01
期刊：
影响因子：
1.8
通讯作者：
Shimojo, S
中科院分区：
文献类型：
--
作者：
Murakami, I;Shimojo, S
作为一种检测运动差异的机制，我们提出了一种“运动对比检测器”模型，该模型在运动方向上具有中心-周围对抗性感受野。在诱导运动、运动捕捉和运动后效应的研究中获得了支持证据。为了在更严格控制的情况下获得进一步的证据，我们研究了由另一个中心刺激引起的运动的知觉偏倚，周围运动。通过采用中心-环绕同心方式配置的随机点显示器，我们测量了中心刺激中的%信号，该信号使刺激在移动的环绕中感知静止。测量了各种刺激大小和偏心率，偏差量随刺激大小和偏心率的变化而变化，在一些偏心率下，较小的刺激大小倾向于产生同化型偏差。然而，空间标度分析表明，同化型偏倚随着尺寸的增大而转变为对比型偏倚，且随着尺寸的增大，同化型偏倚逐渐增大，在一定尺寸时达到对比型偏倚的峰值，并随着尺寸的增大而略有减小。从这些结果中，我们得出结论，感知相对运动的特定过程是由运动对比度检测器介导的，该检测器可能位于MT区域。
As a mechanism to detect differential motion, we have proposed a model of ''a motion contrast detector'' that has a center-surround antagonistic receptive field with respect to the direction of motion, Supporting evidence has been obtained in the studies of induced motion, motion capture, and motion aftereffect, In order to obtain further evidence in a more strictly controlled situation, we examined the perceptual bias of motion in a center stimulus induced by another, surrounding motion, By using a stochastic random-dot display configured in a center-surround concentric fashion, we measured the % signal in the center stimulus that made the stimulus perceptually stationary in the presence of a moving surround, Measurements were done for various stimulus sizes and eccentricities, The amount of bias changed as a function of stimulus size and eccentricity, At several eccentricities, smaller stimulus sizes tended to yield assimilation-type biases, whereas larger sizes tended to yield contrast-type biases, However, a spatial scaling procedure revealed that the amount of bias was a simpler function of ''scaled'' stimulus size that was obtained by dividing the physical size by a scaling factor at each eccentricity, In the scaled profile, assimilation-type bias changed to contrast-type bias with increasing size, reached the peak of contrast-type bias at a certain size, and decreased slightly with further increasing size, Furthermore, a model of a difference of Gaussians, DOG, function well approximated the behavior of the profile, From these results, we concluded that the process specific to perceiving relative motion is mediated by a motion contrast detector, which is possibly located in area MT. Copyright (C) 1996 Elsevier Science Ltd.