van der Smagt Maarten J, Verstraten Frans A J, Paffen Chris L E
Utrecht University, Helmholtz Institute, Experimental Psychology Division, Heidelberglaan 2, 3584 CS Utrecht, Netherlands.
Vision Res. 2010 Aug 23;50(18):1900-4. doi: 10.1016/j.visres.2010.06.012. Epub 2010 Jun 25.
We investigated whether center-surround interactions affect perceived speed in a manner similar to their effects on direction discrimination thresholds [e.g. Tadin, D., Lappin, J. S., Gilroy, L. A., & Blake, R. (2003). Perceptual consequences of center-surround antagonism in visual motion processing. Nature, 424, 312-315]. Observers were asked to match the speed of a test stimulus (a grating, with fixed contrast and no surround) to that of a reference stimulus of variable contrast and with a variably sized surround, moving at one of two possible velocities (1 and 12cps). At 1-cps, both lowering contrast and increasing surround-size resulted in a decrease in perceived speed, except for very low contrast stimuli, where a larger surround resulted in an increase in perceived speed. Although the effect of surround-size was comparable in the two velocity conditions, the effect of contrast was different at 12-cps. That is, in the 12cps condition, a decrease in perceived speed was observed only for the lowest contrast used. Our results suggest that, at least for the lower velocity used, center-surround interactions affect perceived speed in a manner analogous to their effect on direction discrimination.
我们研究了中央-周边相互作用是否会以类似于其对方向辨别阈值的影响方式来影响速度感知[例如，塔丁，D.，拉平，J. S.，吉尔罗伊，L. A.，& 布莱克，R.（2003年）。视觉运动处理中中央-周边拮抗的感知后果。《自然》，424，312 - 315]。要求观察者将测试刺激（一个具有固定对比度且无周边的光栅）的速度与具有可变对比度和可变大小周边、以两种可能速度之一（1和12周/秒）移动的参考刺激的速度相匹配。在1周/秒时，降低对比度和增加周边大小都会导致感知速度降低，但对于对比度非常低的刺激除外，在这种情况下较大的周边会导致感知速度增加。尽管周边大小的影响在两种速度条件下相当，但对比度的影响在12周/秒时有所不同。也就是说，在12周/秒的条件下，仅在使用的最低对比度时观察到感知速度降低。我们的结果表明，至少对于所使用的较低速度，中央-周边相互作用以类似于其对方向辨别的影响方式来影响速度感知。
