Adaptation and optimization of information processing in the early visual cortex

大脑可以说是世界上最强大、最复杂的计算机。这项拟议的研究计划的主要目标是了解大脑执行的计算类型。这项研究侧重于大脑负责视觉的部分，因为作为系统输入的视觉刺激可以被精确控制。虽然眼睛能探测到光，但大脑完成了大部分工作，让我们能够看到周围的世界。数以百万计的脑细胞，也被称为神经元，一起工作来分析投射到眼睛后面的视觉场景。人们很早就知道，位于大脑初级视觉皮质的神经元可以检测视觉场景中的特定特征，如线条或边缘。有趣的是，这些神经元的首选刺激可以以一种上下文相关的方式改变。空间中一个特征周围的东西和最近观察到的东西都会影响初级视觉皮质中的神经元对视觉刺激的反应。这项拟议的研究将使用电生理学方法记录猫初级视觉皮质中的单个神经元，以阐明这些上下文相关变化的机制和功能。此外，这些神经元的反应将使用形式信息理论进行检查，以评估上下文相关的变化是否可以提高视觉处理的准确性或效率。最后，人类心理物理学将被用来研究假设也发生在人类初级视觉皮质中的上下文相关变化如何影响视觉感知。从信息处理的角度来看，这些研究的结果将是令人着迷的，因为尽管单个神经元不断调整其反应特性，但仍保持了稳定的视觉现实。这项研究还将有助于开发更准确的初级视觉皮质计算机模拟，从而帮助我们理解早期皮质编码，并可能对计算机视觉的仿生模型起到启发作用。

The brain is arguably the most powerful and complex computer in the world. The broad aim of the proposed research program is to understand the types of calculations that are performed by the brain. This research focuses on parts of the brain responsible for vision because the visual stimuli that serve as inputs to the system can be precisely controlled. Although the eyes detect light, it is the brain that does most of the work that allows us to see the world around us. Millions of brain cells, also called neurons, work together to analyze the visual scene that is projected onto the back of the eye. It has been known for a long time that neurons located in a part of the brain called the primary visual cortex detect specific features such as lines or edges in the visual scene. Interestingly, the preferred stimulus of these neurons can change in a context-dependent manner. What surrounds a feature in space and what has been observed in the recent past both affect how neurons in the primary visual cortex respond to a visual stimulus. The proposed research will use electrophysiological methods to record from individual neurons in the primary visual cortex of cats to clarify the mechanisms and function of these context-dependant changes. Furthermore, the responses of these neurons will be examined using formal information theory to asses whether context-dependent changes could improve the accuracy or efficiency of visual processing. Finally, human psychophysics will be used to investigate how the context-dependent changes presumed to also occur in human primary visual cortex affect visual perception. The results of these studies will be fascinating from an information processing perspective because a stable visual reality is maintained despite the fact that individual neurons continuously adjust their response properties. The proposed research will also contribute to the development of more accurate computer simulations of the primary visual cortex thereby aiding our understanding of early cortical coding, and may serve as inspiration to biomimetic models of computer vision.