Qiu S X, Caldwell C L, You J Y, Mendola J D
McGill Vision Research & Department of Ophthalmology and Visual Sciences. McGill University, Montreal, Quebec, Canada.
McGill Vision Research & Department of Ophthalmology and Visual Sciences. McGill University, Montreal, Quebec, Canada.
Vision Res. 2020 Oct;175:41-50. doi: 10.1016/j.visres.2020.06.006. Epub 2020 Jul 18.
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.
双眼竞争是指当两个不相容的图像同时分别呈现给每只眼睛时，这两个图像相互竞争以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双眼抑制的机制。莱尔特命题（Levelt's Propositions）是一组五十多年前首次发表的四个命题，不仅有助于描述双眼竞争的感知动态，还能为评估使用不同刺激类型时双眼竞争的共同或差异神经机制提供一个度量标准。在本研究中，我们进行了一系列心理物理学实验，比较了两种截然不同类型刺激的竞争动态。正交光栅是一种经典的竞争刺激类型，与亮度斑块形成对比，亮度斑块是一种相对较少被研究的竞争刺激类型。我们的结果表明，与正交光栅类似，仅亮度竞争中的交替感知也能用修正后的莱尔特命题来描述，尽管亮度斑块的交替速率明显更慢。然而，与在定向光栅转换期间观察到的混合感知不同，亮度竞争期间的融合感知很常见，可能很明亮，并且遵循相同的命题，这表明存在一种三稳态机制。总体而言，这两种类型的竞争都与最近的模型一致，这些模型假设在神经回路中存在独立的双眼和单眼通道，这些通道也能实现对比度归一化。最后，在双眼总和与抑制以及费希纳悖论的背景下讨论了亮度竞争。
