Understanding Higher Order Color: Beyond the Cardinal Mechanisms

人类通常依赖视觉作为他们与世界互动的主要感觉。了解高阶皮质脑过程如何对人类视觉感知做出贡献是认知科学中的一个关键问题。颜色为理解大脑感知机制提供了一个独特的机会，因为颜色处理的第一步，即视网膜细胞（光感受器）对光的吸收，已经完全了解。这些知识使色彩科学家能够操纵神经系统中的早期信号并测量感知结果。知觉和神经生理学实验表明，来自眼睛中不同光感受器的信号近似通过加法和减法组合。我们看到颜色和区分颜色的能力是这些神经总和和差异的结果。在过去的半个世纪里，感知科学家们一直试图了解这些神经颜色机制的数量和性质：颜色机制是少还是多？它们只是增加和减少感光器信号还是进行更复杂的计算？目前的工作结合了新的实验技术和策略的计算建模。在某些情况下，随机的视觉闪烁元素将出现在测试刺激上。如果噪声和测试通过相同的颜色机制进行处理，则噪声应该阻碍人们看到测试颜色的能力（通过伪装等过程）。如果噪声和测试在单独的机制中处理，则噪声应该对看到测试的能力没有任何影响。颜色机制的特性将通过改变噪声相对于测试的颜色来定量研究。了解大脑如何处理颜色信息是更全面地了解我们如何感知周围世界的重要组成部分。这项研究也有实际应用：颜色是信号系统和信息显示的重要组成部分。拥有色彩视觉的定量模型将有助于驾驶舱和汽车显示器、医疗信息和成像显示器，甚至数字电视系统的设计师更有效、更准确地向用户传达信息。

Humans typically rely on vision as their primary sense in their interactions with the world. Understanding how higher-order cortical brain processes contribute to human visual perception is a critical issue in cognitive science. Color offers a unique opportunity for understanding the brain mechanisms of perception because the very first step in color processing, the absorption of light by cells in the retina (photoreceptors), is fully understood. This knowledge allows the color scientist to manipulate early signals in the nervous system and measure the perceptual result. Perceptual and neurophysiological experiments have shown that signals from the different photoreceptors in the eye are combined, approximately by addition and subtraction. Our ability to see colors and to discriminate one color from another are the result of these neural sums and differences. For about the past half-century, perceptual scientists have tried to understand the number and nature of these neural color mechanisms: Are there few color mechanisms or many? Do they just add and subtract photoreceptor signals or do they perform more complex calculations? The present work combines computational modeling with novel experimental techniques and strategies. In some cases, random visual flickering elements will appear over a test stimulus. If the noise and test are processed through the same color mechanisms, the noise should hinder the ability of a person to see the test color (by a process like camouflage). If the noise and test are processed in separate mechanisms, the noise should have no effect on the ability to see the test at all. The properties of the color mechanisms will be quantitatively studied by varying the color of the noise relative to the test.Understanding how the brain processes color information is an important part of the more general understanding of how we perceive the world around us. There are practical applications of this research as well: Color is an important part of signaling systems and information displays. Having a quantitative model of color vision will help the designer of cockpit and automotive displays, medical information and imaging displays, and even digital television systems, to more efficiently and accurately convey information to users.