Traveling wave in visual cortex during binocular rivalry

描述（由申请人提供）：当两只眼睛看到不同的图案时，一个人会经历一种称为双目竞争的感知现象。而不是看到两种模式叠加，他们被认为是交替的。这种现象之所以引人注目，是因为持续的身体刺激和波动的感知体验之间的分离。由于这种分离，双目竞争为研究视觉意识提供了一个机会，视觉意识是生物医学科学面临的最深奥的谜团之一。尽管这一主题引起了广泛的兴趣，并有大量高质量的工作，但许多关于双目竞争背后的神经处理的核心问题仍然没有解决。尤其有争议的是初级视觉皮层（V1）在竞争中的作用。为了解决这一争议，我们建议利用感知现象的一个有趣方面；在交替过程中，我们看到一种行波，其中一种模式的主导地位在局部出现，并逐渐扩大，因为它使另一种模式不可见。我们的实验旨在测量和表征这些感知波的神经基础。

DESCRIPTION (provided by applicant): When the two eyes view dissimilar patterns, one experiences a perceptual phenomenon called binocular rivalry. Instead of seeing both patterns superimposed, they are perceived in alternation. What makes this phenomenon remarkable is the dissociation between a constant physical stimulation and fluctuating perceptual experience. Because of this dissociation, binocular rivalry presents an opportunity for studying visual awareness, one of the deepest mysteries facing biomedical science. In spite of widespread interest, and an impressive volume of high-quality work on this topic, many of the central questions concerning the neural processing underlying binocular rivalry remain open. Particularly controversial is the role of primary visual cortex (V1) in rivalry. To address this controversy, we propose to capitalize on an interesting aspect of the perceptual phenomenon; during an alternation, one sees a traveling wave in which the dominance of one pattern emerges locally and expands progressively as it renders the other pattern invisible. Our experiments are designed to measure and characterize the neural basis of these perceptual waves. The proposed experiments will apply a combination of empirical methods (psychophysics and fMRI in humans; optical imaging, electrophysiology, pharmacology, and electrical stimulation in the awake monkey) to explain this perceptual phenomenon in terms of the underlying neural mechanisms and to test the following hypotheses: (1) that competition between the two rival stimuli is implemented by neural circuits in primary visual cortex (V1), i.e., that neural circuits in V1 play a causal role in triggering transitions during rivalry; (2) that for the consequences of this neural competition to be perceived, activity must advance to higher visual areas; and (3) that attention, mediated by feedback from higher visual areas, plays a crucial role in promoting neural activity from V1 to higher visual areas. We will then be in a position to develop and refine a computational theory of the neural processing in V1 that supports these traveling waves, and a theory that elaborates the role of V1 in visual awareness. The neural competition underlying perceptual alternations during rivalry is believed to be closely related to the strabismic suppression. Hence, the proposed experiments will provide useful information and will establish novel experimental protocols that can, in future work; be applied to further our understanding of strabismus and amblyopia.