Using Contextual Effects to Test Theories of Coding in Visual Cortex

视觉皮质是大脑中处理视觉场景的主要结构。大脑皮层中的细胞有选择地对场景的特征做出反应，如物体的方向、它们移动的方向以及它们相对于背景的亮度。皮层细胞排列在视觉空间的地形图中，以便附近的细胞对图像附近部分的光做出反应。最近的进展表明，细胞之间相互交谈，因此视野某一部分的刺激可以影响细胞对其他区域的反应。细胞之间的这种交流对于引导大脑专注于视觉场景中最重要的区域非常重要，这一过程被称为注意力。例如，鼠标在某人的视线周围移动时，会将他们的注意力从场景中其他地方的物体上移开。该项目旨在研究视觉皮质细胞协同引导注意力的方式。注意力很重要，因为它减少了以相同的精度处理视觉场景中所有细节的需要，留出了更多的资源来处理重要的事情。注意力缺陷是阅读障碍患者的一个问题，因此了解注意力的生理基础是一个重要的目标。除了注意力，视觉系统还具有从视觉场景中选择重要信息的一系列其他机制。例如，视觉自适应倾向于提高对视觉场景中的变化进行编码的能力，但代价是降低系统的整体灵敏度。该项目将研究视觉皮质中注意机制和适应机制之间的关系。我们希望建立精确的生理机制，驱动哺乳动物大脑中的适应和注意机制。

The visual cortex is the main structure in the brain that processes the visual scene. Cells in the cortex respond selectively to features of the scene such as the orientation of objects, the direction they move and their brightness relative to the background. Cortical cells are arranged in a topographic map of visual space, so that nearby cells respond to light from nearby parts of the image. Recent advances have shown that cells talk to each other so a stimulus in one part of the visual field can influence the responses of cells looking at other regions. This communication between cells is important in guiding the brain to focus on areas of the visual scene that are most important, a process known as attention. An example would be that a mouse moving through the periphery of someone's vision would attract their attention away from objects elsewhere in the scene. This project is designed to study the way that cells in the visual cortex cooperate to guide attention. Attention is important because it reduces the need to process all the detail in the visual scene with the same level of accuracy, leaving more resources free to process what is important. Attention deficits are a problem for people with dyslexia, so understanding the physiological basis of attention is an important goal. As well as attention, the visual system has a range of other mechanisms to select important information from the visual scene. For example, visual adaptation tends to improve the ability to code changes in the visual scene at the expense of reducing the sensitivity of the system overall. This project will investigate the relationship between attentional and adaptive mechanisms in the visual cortex. We expect to establish the precise physiological mechanisms that drive adaptive and attentional mechanisms in the mammalian brain.