Mussap A J, Crassini B
Department of Psychology, Deakin University, Geelong, Victoria, Australia.
Perception. 1993;22(10):1155-74. doi: 10.1068/p221155.
The barber-pole illusion and its influence on plaid perception were investigated in two experiments to test the following expectations: (i) apertures which bias the perception of grating motion in directions consistent with plaid direction will facilitate plaid perception, and (ii) apertures which bias the perception of grating motion in directions inconsistent with plaid direction will disrupt plaid perception. In experiment 1 the barber-pole illusion was measured as a function of grating orientation (20 degrees, 45 degrees, and 70 degrees, clockwise and counterclockwise from horizontal), and aperture shape (vertical, horizontal; at each of three elongations). Barber-pole illusions reported with 45 degrees gratings increased with increased aperture elongation. However, this was not found with 20 degrees and 70 degrees gratings; these were almost always reported as moving in a direction parallel to the side of the aperture with which the gratings formed angles approaching 90 degrees. In experiment 2 this dependence of barber-pole illusions on the relative orientation between gratings and apertures was also evident with 45 degrees gratings in oblique apertures; only oblique directions of grating motion were reported. The influence of the same apertures on the separate contrast thresholds required for initial plaid coherence and initial plaid decomposition was measured. In experiments 1 and 2, coherence thresholds were unaffected by apertures, contrary to expectation (i). However, in both experiments expectation (ii) was confirmed; decomposition thresholds decreased in apertures which biased perceived direction of gratings towards vertical (plaid direction), and increased in apertures which biased grating motion away from vertical. Adaptation of plaid mechanisms during measurement of decomposition thresholds was proposed to explain the discrepancy between coherence and decomposition data. Taken together, the results were interpreted as reflecting interactions between mechanisms mediating the barber-pole illusion and mechanisms mediating plaid perception.
在两项实验中研究了理发店旋转柱错觉及其对格子图案感知的影响，以检验以下预期：（i）使光栅运动感知偏向与格子图案方向一致的方向的光阑将促进格子图案感知，以及（ii）使光栅运动感知偏向与格子图案方向不一致的方向的光阑将干扰格子图案感知。在实验1中，测量了理发店旋转柱错觉作为光栅方向（从水平方向顺时针和逆时针20度、45度和70度）和光阑形状（垂直、水平；在三种伸长率中的每一种）的函数。报告的45度光栅的理发店旋转柱错觉随着光阑伸长率的增加而增加。然而，在20度和70度光栅中未发现这种情况；这些光栅几乎总是报告为沿与光栅形成接近90度角的光阑边平行的方向移动。在实验2中，理发店旋转柱错觉对光栅和光阑之间相对方向的这种依赖性在倾斜光阑中的45度光栅中也很明显；只报告了光栅运动的倾斜方向。测量了相同光阑对初始格子图案连贯性和初始格子图案分解所需的单独对比度阈值的影响。在实验1和2中，连贯性阈值不受光阑影响，这与预期（i）相反。然而，在两个实验中预期（ii）都得到了证实；在使光栅感知方向偏向垂直（格子图案方向）的光阑中，分解阈值降低，而在使光栅运动偏离垂直方向的光阑中，分解阈值增加。有人提出在分解阈值测量期间格子图案机制的适应来解释连贯性和分解数据之间的差异。综合起来，这些结果被解释为反映了介导理发店旋转柱错觉的机制和介导格子图案感知的机制之间的相互作用。
