Ryan C, Gillam B
School of Psychology, University of New South Wales, Kensington, Australia.
Perception. 1993;22(4):403-18. doi: 10.1068/p220403.
Prolonged inspection of a surface slanted in the third dimension of visual space typically results in a negative aftereffect such that, after adaptation, a surface in the fronto-parallel plane will appear slanted in the opposite direction. Binocular disparity is not necessary to generate such effects, since they can be obtained monocularly, presumably via adaptation to texture gradient. Six experiments demonstrated durable stereoscopic depth aftereffects in the absence of a texture gradient--by using discrete disparate objects rather than slanted surfaces--and demonstrated that adaptation was to the interobject disparity gradient rather than to the relative disparity of the objects per se. The disparity required to null the obtained aftereffects was inversely proportional to the horizontal separation of elements, for a constant disparity, and directly proportional to the separation of subsequently presented probes. When elements differed in depth (disparity), but were not laterally separated, nulling disparity was significant but invariant with changes in the horizontal separation of probe elements. In that case, adaptation was (i) either to the disparity gradient generated by the vertical separation of probe elements (of which the relative disparity component was tapped); or (ii) to relative disparity per se.
对在视觉空间第三维度中倾斜的表面进行长时间观察通常会产生负后效，即适应后，额状平行平面中的表面会显得向相反方向倾斜。产生这种效果并不需要双眼视差，因为单眼也可以获得这种效果，推测是通过对纹理梯度的适应。六个实验证明，在没有纹理梯度的情况下也会产生持久的立体深度后效——通过使用离散的视差物体而不是倾斜表面——并证明适应的是物体间视差梯度，而不是物体本身的相对视差。对于恒定视差，消除所获得后效所需的视差与元素的水平间距成反比，与随后呈现的探测物的间距成正比。当元素在深度（视差）上不同但没有横向分离时，消除视差是显著的，但不随探测元素水平间距的变化而变化。在这种情况下，适应（i）要么是对由探测元素垂直间距产生的视差梯度（利用了其中的相对视差成分）；要么是（ii）对相对视差本身。
