Deciphering the elemental building blocks of visual appearance

解读视觉外观的基本构建块

• 批准号: 430279747
• 负责人: Dr. Wolf Harmening
• 金额: --
• 依托单位: Universitäts-Augenklinik Bonn
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/430279747?language=en
• 关键词: Deciphering; elemental; building; blocks; visual

Seeing is a product of a complex physical and physiological chain of events. While some isolated stages of the visual pathway are well understood, studying the direct link between the physical stimulus and perception remains one of the challenges in vision science. In humans, the activation of the retinal photoreceptor mosaic constitutes the cellular entry point of the visual signal. To isolate the single cell contribution to the overall percept is difficult, because in normal viewing, tens of thousands of photoreceptors are stimulated at any given moment. Moreover, precise experimental access is hindered by the optical imperfections and the constant movement of the eye. Recent advances in adaptive optics micro-stimulation, however, now make it possible to target single photoreceptor cells in the living retina for isolated function testing.Here, we ask in how far each individual photoreceptor contributes to the visual percept and if elemental cellular signals also instantiate perceptual elements. How does it look to see with only a single photoreceptor, and how do these elemental percepts combine and interact when stimuli are more complex? We will tackle these questions by direct mapping of highly controlled single (and multiple) cell stimulation and the subjective appearances they elicit. While the microscopic mapping between single cell stimulation and appearance is to-date entirely unknown, there is also a lack of understanding of the relation between stimulus and appearance on a macroscopic level, i.e. the more natural condition of spatially extended stimuli. One reason is that by far the largest part of vision research uses performance measures, like visual acuity or sensitivity, to study how well visual stimuli can be detected or discriminated, but not how they appear subjectively. To understand the underlying mechanisms of visual space perception, however, it is important to have a precise account of one of the central outputs of the system — visual appearance. Here, we will combine micro and macro captures of visual appearance, all the way from the single cone in the fovea to large arrays of cones in the periphery. To this end, we will develop novel procedures to accurately quantify subjective appearance and apply these methods in a number of paradigms that are known to alter stimulus appearance. By combining cutting-edge high-resolution optical stimulation techniques with novel appearance-based psychophysical methods in a large range of behavioral experiments, we aim to uncover the elemental building blocks of visual space perception.

视觉是一系列复杂的生理和生理事件的产物。虽然视觉通路的一些孤立阶段已经被很好地理解，但研究物理刺激和知觉之间的直接联系仍然是视觉科学中的挑战之一。在人类中，视网膜光感受器马赛克的激活构成了视觉信号的细胞入口点。要分离出单个细胞对整体感知的贡献是困难的，因为在正常的观看中，在任何给定的时刻都会刺激数万个光感受器。此外，光学缺陷和眼睛的持续运动阻碍了精确的实验访问。然而，自适应光学微刺激的最新进展使我们有可能针对活的视网膜中的单个光感受器细胞进行单独的功能测试。在这里，我们询问每个单独的光感受器对视觉感知的贡献有多大，以及基本的细胞信号是否也实例化感知元素。只有一个光感受器看起来是什么样子，当刺激更复杂时，这些基本感知是如何组合和相互作用的？我们将通过直接映射高度受控的单个(和多个)细胞刺激及其引发的主观现象来解决这些问题。虽然到目前为止，单细胞刺激和外观之间的微观映射是完全未知的，但在宏观层面上也缺乏对刺激和外观之间的关系的理解，即更自然的空间扩展刺激条件。一个原因是，到目前为止，视觉研究的最大部分是使用视觉敏锐度或敏感度等性能指标来研究视觉刺激被检测或辨别的程度，而不是它们的主观外观。然而，要了解视觉空间知觉的潜在机制，重要的是要对系统的中心输出之一--视觉外观--有一个准确的解释。在这里，我们将结合视觉外观的微观和宏观捕捉，从中央凹的单个视锥到外围的大视锥阵列。为此，我们将开发新的程序来准确量化主观外观，并将这些方法应用于一些已知可以改变刺激外观的范例中。通过在大范围的行为实验中将尖端的高分辨率光学刺激技术与新的基于外表的心理物理方法相结合，我们的目标是揭示视觉空间感知的基本构件。