Grossberg Stephen, Yazdanbakhsh Arash, Cao Yongqiang, Swaminathan Guru
Department of Cognitive and Neural Systems, Boston University, 677 Beacon Street, Boston, MA 02215, USA.
Vision Res. 2008 Sep;48(21):2232-50. doi: 10.1016/j.visres.2008.06.024. Epub 2008 Aug 13.
Under natural viewing conditions, a single depthful percept of the world is consciously seen. When dissimilar images are presented to corresponding regions of the two eyes, binocular rivalry may occur, during which the brain consciously perceives alternating percepts through time. How do the same brain mechanisms that generate a single depthful percept of the world also cause perceptual bistability, notably binocular rivalry? What properties of brain representations correspond to consciously seen percepts? A laminar cortical model of how cortical areas V1, V2, and V4 generate depthful percepts is developed to explain and quantitatively simulate binocular rivalry data. The model proposes how mechanisms of cortical development, perceptual grouping, and figure-ground perception lead to single and rivalrous percepts. Quantitative model simulations of perceptual grouping circuits demonstrate influences of contrast changes that are synchronized with switches in the dominant eye percept, gamma distribution of dominant phase durations, piecemeal percepts, and coexistence of eye-based and stimulus-based rivalry. The model as a whole also qualitatively explains data about the involvement of multiple brain regions in rivalry, the effects of object attention on switching between superimposed transparent surfaces, monocular rivalry, Marroquin patterns, the spread of suppression during binocular rivalry, binocular summation, fusion of dichoptically presented orthogonal gratings, general suppression during binocular rivalry, and pattern rivalry. These data explanations follow from model brain mechanisms that assure non-rivalrous conscious percepts.
在自然观察条件下，人们能有意识地看到关于世界的单一深度感知。当将不同的图像呈现给双眼的相应区域时，可能会出现双眼竞争，在此期间大脑会随着时间有意识地感知交替出现的感知。产生关于世界的单一深度感知的相同大脑机制，是如何导致感知双稳态，尤其是双眼竞争的呢？大脑表征的哪些属性与有意识看到的感知相对应？本文构建了一个关于皮层区域V1、V2和V4如何产生深度感知的皮层分层模型，以解释并定量模拟双眼竞争数据。该模型提出了皮层发育、感知分组和图形-背景感知机制如何导致单一和竞争感知。感知分组电路的定量模型模拟展示了与优势眼感知切换同步的对比度变化、优势相位持续时间的伽马分布、零碎感知以及基于眼睛和基于刺激的竞争共存的影响。整体模型还定性地解释了关于多个脑区参与竞争、物体注意力对叠加透明表面之间切换的影响、单眼竞争、马罗昆图案、双眼竞争期间抑制的扩散、双眼总和、双眼呈现的正交光栅的融合、双眼竞争期间的一般抑制以及图案竞争等数据。这些数据解释源于确保无竞争的有意识感知的模型脑机制。
