Neural coding of natural stimuli in freely moving macaque

尽管视觉感知代表了我们日常生活的一个基本方面，但我们的知识 对自然刺激的潜在神经编码是可悲的缺乏。一个主要的限制阻止我们 对自然视觉的神经基础的理解是缺乏可行的记录方法， 自由移动的猴子在无限制的 探索行为事实上，传统上， 通过在实验室环境中研究非人类灵长类动物的大脑， 在计算机显示器上呈现合成刺激时受到约束。然而，它已变得越来越 很明显，在空间受限的人工实验室中研究大脑严重限制了我们的能力， 了解大脑回路的功能。为了克服这些限制，我们提出了一种新的方法， 设计一个集成的无线眼动跟踪系统，以精确记录自然发生的眼动， 在整个非结构化的，自由移动的行为结合大规模的，无线的视觉输入 四个皮层区域的群体活动的电子记录。我们的新系统将用于研究 通过记录自然视觉探索过程中皮层动力学的视觉编码和大脑状态依赖性 当非人类灵长类动物相互作用时，多个视觉、颞叶和额叶皮层区域的群体活动 与他们的环境。我们将重点关注群体响应的稀疏性， 自然场景和刺激编码的空间位置依赖性。我们假设，稀疏编码的 在自由观看期间的自然刺激提高了神经群体对刺激进行编码的准确性。 视觉皮层的层次结构我们提出的研究将构成一个范式转变， 神经科学-从简单地观察动物行为和记录单细胞的反应-到一个 定量理解的分布式神经网络编码过程中的无任务行为在自由 移动的非人类灵长类动物与它们的物理环境相互作用。我们预计， 使用我们的方法记录的神经数据将引起临床医生和计算神经科学家的极大兴趣 研究正常和功能失调的神经网络的一般特性，可能导致医学见解 皮层视觉障碍和皮层修复术的创新，以恢复自然的视觉功能。

Despite the fact that visual perception represents such a fundamental aspect of our everyday life, our knowledge of the underlying neural coding of natural stimuli is woefully lacking. One major limitation preventing our understanding of the neural underpinnings of natural vision is the lack of viable methodologies for recording and synchronizing eye movements and incoming visual stimuli from freely-moving monkeys during unrestrained exploratory behavior. Indeed, examining the neural bases of visual perception has been traditionally performed by studying the brain of nonhuman primates in a laboratory environment in which the head and body are restrained while synthetic stimuli are presented on a computer monitor. However, it has become increasingly clear that studying the brain in spatially confined, artificial laboratory rigs poses severe limits on our capacity to understand the function of brain circuits. To overcome these limitations, we propose a novel approach by designing an integrated wireless eye tracking system to precisely record naturally-occurring eye movements and retinotopic visual inputs throughout unstructured, freely-moving behavior in conjunction with massive, wireless electrical recordings of population activity across four cortical areas. Our novel system will be used to study the visual coding and brain state-dependence of cortical dynamics during natural visual exploration by recording population activity in multiple visual, temporal, and frontal cortical areas while nonhuman primates are interacting with their environment. We will focus on the sparseness of the population response, the real-time encoding of natural scenes, and spatial position dependency of stimulus coding. We hypothesize that the sparse coding of natural stimuli during free viewing improves the accuracy with which neural populations encode stimuli across the visual cortical hierarchy. Our proposed research will constitute a paradigm shift by moving visual neuroscience - from simply observing animal behavior and recording the responses of single cells - to a quantitative understanding of the distributed neuronal network encoding during task-free behavior in freely moving nonhuman primates interacting with their physical environment. We anticipate that the large quantity of neural data recorded using our approach will be of great interest to clinicians and computational neuroscientists studying general properties of normal and dysfunctional neural networks, possibly leading to medical insights into cortical visual impairments and innovations in cortical prosthetics for restoring natural visual functions.