Traveling waves in visual cortex during binocularrivalry

描述(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眼竞争的知觉现象。人们不是看到两种模式叠加在一起，而是交替感知。这一现象之所以引人注目，是因为持续的身体刺激和波动的知觉体验之间的分离。由于这种分离，双目竞争为研究视觉感知提供了机会，视觉感知是生物医学科学面临的最深层次的谜团之一。尽管在这一主题上引起了广泛的兴趣，并有大量的高质量工作，但许多关于双眼竞争背后的神经处理的核心问题仍然悬而未决。尤其有争议的是初级视觉皮质(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；在交替期间，人们看到一个行波，其中一种模式的主导地位在局部出现，并随着它使另一种模式不可见而逐渐扩大。我们的实验旨在测量和描述这些感知波的神经基础。 拟议的实验将应用经验方法(人类的心理物理学和功能磁共振；清醒猴子的光学成像、电生理学、药理学和电刺激)来从潜在的神经机制来解释这种知觉现象，并检验以下假设：(1)两个相互竞争的刺激之间的竞争是由初级视觉皮质(V1)的神经回路实现的，即V1的神经回路在触发竞争过程中的转换中起着因果作用；(2)为了使这种神经竞争的结果被感知，活动必须提前到更高的视觉区域；(3)在高级视觉区域反馈的调节下，注意在促进从V1到高级视觉区域的神经活动中起着至关重要的作用。然后，我们将能够开发和完善支持这些行波的V1神经处理的计算理论，以及阐述V1在视觉感知中的作用的理论。 竞争过程中知觉变化的神经竞争被认为与斜视抑制密切相关。因此，拟议的实验将提供有用的信息，并将建立新的实验方案，这些方案可以在未来的工作中应用于进一步了解斜视和弱视。

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.