Time-Locked Psychophysics: Speeded Responses to Visual Stimuli

颜色是人类体验的核心，影响我们的情绪，我们对食物、衣服的选择，甚至我们所有的视觉行为。但人类是如何处理颜色的，在很大程度上仍然是一个谜。更好地理解人类的颜色视觉在成像、材料和纺织、建筑和照明设计中有许多实际应用。这些模型中的许多只与基本的人类颜色机制松散地联系在一起，部分原因是缺乏良好的基本颜色过程模型。人类大脑包含数百万个神经细胞，当环境中发生事件时，这些神经细胞会做出反应。对于视觉刺激，神经反应始于眼睛的视网膜，并被传输到大脑，在那里它们创造了我们对周围世界的有意识的感知。在其他方面，神经活动发出光的颜色的信号。这一过程是快速的，但不是瞬间的。这个项目使用新的程序来测量眼睛神经活动的第一分之一秒内由颜色触发的行为反应，并研究这些反应如何随着时间的推移在一系列颜色、对比度和适应的背景下发生变化。本研究使用创新的心理物理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由眼睛视网膜对光敏感的细胞的早期活动触发。第二个目标基于这样的假设，即对刺激开始和结束的神经反应通过两条不同的神经路径(开和关路径)传递到大脑。其目的是通过确定由刺激开始和结束触发的反应是否会有不同的颜色，来测试是否可以分别测量和研究开启和关闭反应，尽管两者的物理刺激是相同的。所有实验的结果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属性进行比较。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.