Time-Locked Psychophysics: Speeded Responses to Visual Stimuli

颜色是人类经验的核心，影响着我们的情绪，我们对食物，衣服的选择，甚至我们所有的视觉行为。但是，人类如何处理颜色仍然是一个谜。更好地了解人类的颜色视觉在成像，材料和纺织品，建筑和照明设计中有许多实际应用。许多这些模型只是松散地联系到基本的人类色彩机制，部分原因是缺乏基本色彩过程的良好模型。人类大脑包含数百万个神经细胞，当环境中发生事件时会做出反应。 对于视觉刺激，神经反应开始于眼睛的视网膜，并被传输到大脑，在那里它们创造了我们对周围世界的意识。除此之外，神经活动还发出光的颜色信号。 这个过程是快速的，但不是瞬间的。 该项目使用新颖的程序来测量眼睛神经活动的第一秒内由颜色触发的行为反应，并研究这些反应如何在一系列颜色，对比度和适应背景下随时间变化。本研究采用创新的心理物理学方法来探索光适应和神经视觉信号的分叉是如何影响颜色检测和颜色分类的。 其中一个目标是探索最快的行为反应是否是由眼睛视网膜感光细胞的早期活动触发的。 第二个目标基于这样的假设，即对刺激的开始和结束的神经反应通过两条不同的神经通路（ON和OFF通路）传递到大脑。其目的是通过确定由刺激的开始和结束触发的响应是否可以具有不同的颜色来测试ON和OFF响应是否可以单独测量和研究，即使物理刺激对于两者是相同的。 所有实验的结果都将使用先进的计算方法进行分析，并与眼睛中神经细胞的已知特性进行比较。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Color is central to human experience, influencing our moods, our choices of foods, clothes, and indeed all our visual behavior. But much about how humans process color is still a mystery. A better understanding of human color vision has many practical applications in imaging, materials and textiles, architecture and lighting design. Many of these models are only loosely tied to basic human color mechanisms, in part because of a lack of good models of fundamental color processes. The human brain contains millions of nerve cells that respond when an event occurs in the environment. For visual stimuli, the neural responses start in the retina of the eye and are transmitted to the brain where they create our conscious awareness of the world around us. Among other things, the neural activity signals the color of the light. This process is fast, but not instantaneous. This project uses novel procedures to measure behavioral responses that are triggered by color in the very first fraction of a second of nerve activity in the eye and study how those responses change over time over a range of colors, contrasts, and adapting backgrounds. This research uses innovative psychophysical methods to explore how light adaptation and the bifurcation of neural visual signals underlie chromatic detection and color categorization. One goal is to explore whether the fastest behavioral responses are triggered by the very early activity in the light-sensitive cells of the retina of the eye. A second goal rests on the hypothesis that neural responses to the start and end of a stimulus are carried in two different nerve pathways to the brain (the ON and OFF pathways). The aim is to test whether the ON and OFF responses can be measured and studied separately, by determining whether responses triggered by the start and end of a stimulus can have different colors even though the physical stimulus is the same for both. Results from all experiments will be analyzed using advanced computational methods and compared with the known properties of nerve cells in the eye.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.