School of Psychology, University of Aberdeen, Old Aberdeen, SC, UK.
Department of Psychology, University of California, San Diego, La Jolla, CA, USA.
J Vis. 2023 Oct 4;23(12):10. doi: 10.1167/jov.23.12.10.
Motion, position, and form are intricately intertwined in perception. Motion distorts visual space, resulting in illusory position shifts such as flash-drag and flash-grab effects. The flash-grab displaces a test by up to several times its size. This lets us use it to investigate where the motion-induced shift operates in the processing stream from photoreceptor activation to feature activation to object recognition. We present several canonical, highly familiar forms and ask whether the motion-induced shift operates uniformly across the form. If it did, we could conclude that the effect occurred after the elements of the form are bound. However, we find that motion-induced distortion affects not only the position, but also the appearance of briefly presented, canonical shapes (square, circle, and letter T). Features of the flashed target that were closest to its center were shifted in the direction of motion more than those further from its center. Outline shapes were affected more than filled shapes, and the strength of the distortion increased with the contrast of the moving background. This not only supports a nonuniform spatial profile for the motion-induced shift but also indicates that the shift operates before the shape is established, even for highly familiar shapes like squares, circles, and letters.
运动、位置和形状在感知中是错综复杂地交织在一起的。运动使视觉空间变形,导致虚幻的位置移动,如闪光拖拽和闪光抓取效应。闪光抓取可以将测试对象位移高达其大小的几倍。这使我们能够利用它来研究运动引起的位移在从光感受器激活到特征激活到对象识别的处理流中是如何运作的。我们呈现了几个典型的、高度熟悉的形状,并询问运动引起的位移是否在整个形状上均匀作用。如果是这样,我们可以得出结论,该效果发生在形状的元素被绑定之后。然而,我们发现运动引起的变形不仅影响位置,还影响短暂呈现的、典型形状(正方形、圆形和字母 T)的外观。与中心距离最近的闪烁目标的特征在运动方向上的位移比距离中心较远的特征更大。轮廓形状比填充形状更容易受到影响,并且变形的强度随着运动背景对比度的增加而增加。这不仅支持运动引起的位移具有非均匀的空间分布,还表明该位移在形状建立之前就已经发生,即使对于像正方形、圆形和字母这样高度熟悉的形状也是如此。