Establishing the Physiological Foundations of Visual Function in the Cortex

视觉皮质是大脑处理视觉输入的主要中心。从生理记录中可以知道，这一区域的一部分充当了视觉空间的“地图”，因此视觉世界中特定位置的物体会唤起视觉皮质中特定位置的神经细胞(神经元)的活动。目前尚不清楚空间和时间中的神经活动与对物体及其位置的感知有何关系。这个项目利用一种新的多电极阵列的进一步开发来研究局部刺激如何高度模拟正常的视觉信号。开发了工程技术来连接阵列和大脑，并以一种测试盲人视觉假体可行性的方式提供足够的刺激。将进行电生理测试，试图将刺激模式与视觉感觉阈值联系起来。结果将提供关于空间图案视觉刺激如何产生对世界上物体的视觉感知的有价值的信息。这项工作不仅将对视觉神经科学产生影响，还将对阐明大脑皮层编码的神经生物学原理以及为盲人开发生物工程视觉辅助工具产生影响。

The visual cortex is a main center of the brain for processing visual input. From physiological recordings, it is known that part of this area acts as a "map" of visual space, so that an object in a particular place in the visual world evokes activity in nerve cells (neurons) in a particular place in the visual cortex. It remains unclear just how that neural activity in space and time is related to the perception of an object and its location. This project utilizes further development of a novel multiple-electrode array to investigate how highly local stimuli might mimic normal visual signals. Engineering techniques are developed to interface the array with the brain, and to provide adequate stimulation in a way to test feasibility for a visual prosthesis for the blind. Electrophysiological tests will be done to try to correlate stimulation patterns with thresholds for visual sensation. Results will provide valuable information on how spatially patterned visual stimuli produce visual perceptions of objects in the world. This work will have an impact not only on visual neuroscience, but on clarifying neurobiological principles of coding in the cortex in general, and on the development of bioengineering visual aids for the blind.