Traveling waves in visual cortex during binocular rivalry

描述（由申请人提供）：当两只眼睛看到不同的模式，一个经验的知觉现象称为双眼竞争。它们不是叠加在一起的，而是交替出现的。使这种现象引人注目的是恒定的物理刺激和波动的感知体验之间的分离。由于这种分离，双眼竞争为研究视觉意识提供了机会，这是生物医学科学面临的最深层次的奥秘之一。尽管广泛的兴趣，和令人印象深刻的高质量的工作量在这个话题上，许多核心问题的神经处理基础的双眼竞争仍然开放。特别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，并随着另一种模式的不可见而逐渐扩大。我们的实验旨在测量和表征这些感知波的神经基础。 拟议的实验将采用经验方法的组合（人类的心理物理学和功能磁共振成像;清醒猴子的光学成像，电生理学，药理学和电刺激）来解释这种感知现象的潜在神经机制，并测试以下假设：（1）两个竞争刺激之间的竞争是由初级视皮层（V1）中的神经回路实现的，即，V1区的神经回路在引发竞争过程中的转换中起着因果作用;（2）为了感知这种神经竞争的结果，活动必须推进到更高的视觉区域;（3）注意力，由来自更高视觉区域的反馈介导，在促进从V1区到更高视觉区域的神经活动中起着至关重要的作用。然后，我们将能够发展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在视觉意识中的作用的理论。 竞争过程中知觉交替背后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，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.