Neural coding of natural stimuli in freely moving macaque

尽管视觉感知代表着我们日常生活的一个基本方面，但我们的知识 可悲的是，自然刺激的基本神经编码是缺乏的。一个主要限制阻止了我们的 对自然视觉的神经基础的理解是缺乏可行的记录和 自由活动的猴子在自由活动过程中眼球运动和传入视觉刺激的同步 探索性行为。事实上，研究视觉感知的神经基础一直是传统的做法 通过在实验室环境中研究非人类灵长类动物的大脑，在这个环境中，头部和身体 当合成刺激被呈现在计算机显示器上时受到限制。然而，它已经变得越来越多 显然，在空间有限的人工实验室中研究大脑对我们的能力构成了严重的限制 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，通过 设计集成的无线眼球跟踪系统，精确记录自然发生的眼球运动和 在整个非结构化、自由移动的行为中使用视网膜视觉输入，并结合大规模无线 四个大脑皮层区域的人口活动的电子记录。我们的新系统将被用来研究 自然视觉探索中的视觉编码和大脑状态依赖的皮层动力学 非人灵长类动物相互作用时，多个视觉、颞叶和额叶皮质区域的种群活动 与他们的环境有关。我们将重点关注种群响应的稀疏性，以及对 自然场景，以及刺激编码的空间位置依赖性。我们假设的稀疏编码 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 视觉大脑皮层层次结构。我们提出的研究将通过移动视觉来实现范式的转变 神经科学--从简单地观察动物行为和记录单个细胞的反应--到 对自由活动中分布式神经网络编码的定量理解 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，大量的 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学家的极大兴趣 研究正常神经网络和功能失调神经网络的一般特性，可能会带来医学见解 皮质视觉损伤和皮质假体的创新，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.