Binocular rivalry is the phenomenon that when two incompatible images are simultaneously presented, one to each eye, the two images compete with each other to be the dominant percept. Studying the underlying neural mechanisms of binocular rivalry is useful for understanding the mechanisms of interocular inhibition. Levelt’s Propositions, a set of four propositions that were originally published over fifty years ago, are not only useful for characterizing the perceptual dynamics of binocular rivalry, but can also provide a metric for assessing the common or differential neural mechanisms of binocular rivalry when diverse stimulus types are used. In the present study, we conducted a series of psychophysics experiments, where we compared the rivalry dynamics of two quite different types of stimuli. Orthogonal gratings, a classic type of rivalry stimulus, were contrasted with luminance patches, a type of rivalry stimulus that is relatively less studied. Our results showed that, similar to the orthogonal gratings, the alternate percepts in luminance-only rivalry were described by the modified Levelt’s Propositions, despite the clearly slower alternation rates for luminance patches. However, unlike the mixed percepts observed during transitions between oriented gratings, fusion percepts during luminance rivalry were common, could be lustrous, and obeyed the same Propositions, suggesting a regime of tri-stability. Overall, both types of rivalry are consistent with recent models that posit separate binocular and monocular channels embedded within neural circuits that also accomplish contrast normalization. Finally, luminance rivalry is discussed in the contexts of binocular summation and suppression, as well as Fechner’s paradox.

双目竞争是当两个不相容的图像同时呈现时，每只眼睛一个，这两个图像相互竞争成为主导感知的现象。研究双眼竞争的潜在神经机制有助于理解眼间抑制的机制。Levelt 的命题是一组 4 个命题，最初发表于 50 多年前，不仅可用于表征双眼竞争的知觉动态，而且还可以提供一个衡量标准，用于评估在不同刺激下双眼竞争的共同或差异神经机制类型被使用。在本研究中，我们进行了一系列心理物理学实验，比较了两种完全不同类型刺激的竞争动态。正交光栅，一种经典的竞争刺激类型，与亮度斑块形成对比，后者是一种研究相对较少的竞争刺激类型。我们的结果表明，与正交光栅类似，尽管亮度块的交替速率明显较慢，但修改后的 Levelt 命题描述了仅亮度竞争中的交替感知。然而，与在定向光栅之间的过渡期间观察到的混合感知不同，亮度竞争期间的融合感知是常见的，可能是有光泽的，并且遵循相同的命题，表明存在三稳态机制。总体而言，这两种类型的竞争都与最近的模型一致，这些模型在神经回路中嵌入了单独的双目和单眼通道，这些通道也实现了对比度归一化。最后，