Resolution of chromatic ambiguity in mid-level vision

解决中层视力中的色模糊

• 批准号: 9360622
• 负责人: STEVEN K SHEVELL
• 金额: $ 39.5万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-30 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9360622
• 关键词: Alzheimer' s Disease; Area; Awareness; Brain; Characteristics; Color; Conscious; Dimensions; Eye; Frequencies; Gray unit of radiation dose; Grouping; Human; Image; Knowledge; Lead; Left; Light; Lighting; Link; Measures; Mediating; Methods; Motion; Pattern; Perception; Phase; Process; Property; Research; Resolution; Retinal; Schizophrenia; Shapes; Signal Transduction; Speed; Stimulus; Structure; Sum; Surface; Surface Properties; Techniques; Testing; Text; Textbooks; Vision; Visual; Visual impairment; Work; area V1; base; discount; experimental study; innovation; knowledge base; monocular; neural model; neurotransmission; novel; object perception; object recognition; programs; public health relevance; relating to nervous system; response; segregation; stereoscopic; visual information; visual processing

 DESCRIPTION (provided by applicant): Our ability to see in the natural world depends on neural representations of objects. Signals sent from the eye to the brain are the basis for what we see, but these signals are transformed at many later stages of vision in order to perceive objects. The focus of this research is mid-level vision, a critical intermediate stage after the image-based representation of light in the eye but before knowledge-based object recognition. It is the first stage of representation for edges of surfaces, separation of surfaces from each other, and figure-ground segregation. Mid-level vision includes vital processes for object perception but is studied relatively little. Mid-level representations must solve two basic problems. First, they must integrate spatially separated parts of the scene selectively. Not all parts of a scene should be integrated into the representation for each distinct object, of course, so the selectivit is essential. Though normally effortless, the ability to integrate information from separate visual regions is made salient by perceptual deficits in some cases of Alzheimer's disease and schizophrenia. Second, the information available to be integrated is often ambiguous. Normally the implicit ambiguity is resolved without conscious awareness, though images that fluctuate between two different bi-stable percepts are textbook examples demonstrating neural ambiguity. The research here links these two challenges for mid-level vision by determining how spatially separated ambiguous representations become grouped together. This work requires the ability (1) to experimentally create and control ambiguity in separate mid-level representations localized for distinct regions of visual space and (2) to quantify how each of the separate ambiguous representations is perceived. Both are achieved using an innovative technique called chromatic interocular switch rivalry, which generates ambiguous representations for color at a level beyond monocular stages of visual processing (beyond monocular representations in cortical area V1). Chromatic ambiguity provides a model neural representation for understanding grouping of mid-level ambiguity. Experiments will test how separated ambiguous representations are grouped and resolved. Initial hypothesis tests will determine the temporal and spatial characteristics, motion and three-dimensional percepts that cause mid-level ambiguities in separate areas to become grouped. Further studies will test whether the range covered by the ambiguity itself mediates the grouping that serves to resolve it. Other experiments will extend the research to fully rendered three-dimensional objects to test whether resolution of ambiguity by grouping follows from color-constant surface percepts that discount illumination. In sum, this research will discover new knowledge about ambiguous mid-level representations, delivering an important advance for understanding normal vision as well as visual impairments.

 描述（由申请人提供）：我们在自然世界中的视觉能力取决于物体的神经表征。从眼睛发送到大脑的信号是我们所看到的东西的基础，但是这些信号在视觉的许多后期阶段被转换，以便感知物体。这项研究的重点是中级视觉，这是在眼睛中基于图像的光表示之后，但在基于知识的物体识别之前的关键中间阶段。它是表示曲面边缘的第一阶段，曲面彼此分离， 和图形背景隔离。中级视觉包括物体感知的重要过程，但研究相对较少。 中层代表必须解决两个基本问题。首先，它们必须有选择地整合场景中空间上分离的部分。当然，并不是场景的所有部分都应该集成到每个不同对象的表示中，因此选择性是必不可少的。虽然通常毫不费力，但整合来自不同视觉的信息的能力 在阿尔茨海默病和精神分裂症的某些病例中，知觉缺陷使这些区域变得突出。第二，可供整合的信息往往是模糊的。通常情况下，隐含的模糊性是在没有意识的情况下解决的，尽管在两个不同的双稳态感知之间波动的图像是证明神经模糊性的教科书例子。这里的研究通过确定空间上分离的模糊表示如何组合在一起，将这两个挑战联系起来。 这项工作需要以下能力：（1）在视觉空间的不同区域定位的单独的中级表示中实验性地创建和控制模糊性，以及（2）量化每个单独的模糊表示是如何被感知的。两者都是使用一种称为色眼间开关竞争的创新技术来实现的，该技术在视觉处理的单眼阶段之外（在皮层V1区的单眼表示之外）产生模糊的颜色表示。色度模糊度提供了一个模型神经表示，用于理解中等模糊度的分组。 实验将测试分离的歧义表示如何分组和解决。初始假设检验将确定时间和空间特征、运动和三维感知，这些特征导致不同区域中的中级模糊性成为分组。进一步的研究将测试模糊性本身所覆盖的范围是否介导了用于解决它的分组。其他实验将把研究扩展到完全渲染的三维对象，以测试通过分组解决模糊性是否遵循不考虑照明的颜色恒定表面感知。总之，这项研究将发现关于模糊中级表征的新知识，为理解正常视觉和视觉障碍提供重要的进展。