CRCNS: Spatiotemporal Scene Statistics and Contextual Influences in Vision

描述（由申请人提供）：智力价值：神经科学的一个核心问题是理解皮层网络如何处理复杂的自然刺激。神经生理学研究和计算模型传统上关注于简单的刺激，如光栅和条形。虽然提供了重要的见解，但很难从这些研究中推断出对更自然输入的处理的理解。另一方面，在这一领域取得进展的一个主要障碍是，自然场景是复杂的，我们不清楚一个给定的场景究竟是什么唤起了给定的神经反应。为了克服这一限制，推动我们对自然输入的皮层处理的理解，我们将利用自然场景统计的最新进展，将理论和神经生理学实验紧密结合起来。我们认为将自然图像和电影与随机场景区分开来的关键因素是空间和时间上的联合统计依赖性。此外，我们假设视觉神经元对这些依赖性很敏感。我们将建立一个统一的神经元时空上下文效应建模框架，这是由场景中的统计依赖关系决定的。重要的是，该模型的预测将用于指导神经生理学实验和解释结果。利用自然刺激，我们将测量单个神经元和细胞群体中空间、时间和时空背景的影响，包括确定神经元之间的相互作用如何促进背景效应。我们将在初级视觉皮层（V1）进行记录，因为它为我们的实验提供了坚实的背景。我们将在域外区V2进行平行记录，因为之前的工作表明它可能对上下文信息具有不同的敏感性。实验结果将验证和指导建模框架。我们的方法将是一个重大的进步，比以前的场景统计建模工作，重点是解释有限的情境生理学数据的简单刺激，如光栅，并将首次充分利用场景统计的力量来回答一个基本问题。最重要的是，我们的工作将在阐明皮层回路如何处理自然场景方面取得重大进展，在提供预测和解释能力的理论框架内。合作：该项目将涉及两位具有计算视觉神经科学和系统生理学专业知识的年轻研究人员之间的合作努力；它结合了国家的最先进的算法，从计算视觉和技术记录在早期视觉皮层的神经元群体。我们将通过将理论和模型开发与电生理实验紧密结合来实现我们的目标，这是两位研究者的接近所促进的一种方法。更广泛的影响：该提案预计将在五个主要领域产生广泛影响。首先，这项工作将对基础、生物医学和应用学科产生广泛的影响，包括：研究自然输入下的其他感觉系统；建立卓越的视觉教具；设计人工系统；推进图像和信号处理。其次，数据和刺激方案将通过CRCNS数据共享网站广泛提供给社会各界。第三，项目将用于培养和指导博士后成为独立的研究科学家。第四，该项目将首次向阿尔伯特·爱因斯坦的学生介绍解决神经科学基本问题的理论和实验方法的结合。最后，该项目将作为拓展工作的一部分，让布朗克斯当地代表性不足的高中生接触到令人兴奋的科学研究。

DESCRIPTION (provided by applicant): Intellectual merit: A central question in neuroscience is understanding how cortical networks process complex natural stimuli. Neurophysiological studies and computational models have traditionally focused on simple stimuli, such as gratings and bars. While providing important insights, it is difficult to extrapolate from these studies to an understanding of the processing of more natural input. On the other hand, a main hurdle to making progress in the field is that natural scenes are complex and it is not clear what it is about a given scene that evokes a given neural response. To overcome this limitation and to push forward our understanding of cortical processing of natural inputs, we will make use of recent advances in understanding natural scene statistics to closely integrate theory and neurophysiological experiments. We posit that a key factor distinguishing natural images and movies from random scenes are joint statistical dependencies in space and time. Further, we hypothesize that visual neurons are sensitive to these dependencies. We will build a unified modeling framework of spatiotemporal contextual effects in neurons, which is determined by the statistical dependencies in scenes. Importantly, the predictions of the model will be used to guide neurophysiology experiments and to interpret the results. Using natural stimuli, we will measure effects of spatial, temporal, and spatiotemporal context in single neurons and in populations of cells, including determining how interactions between neurons contribute to contextual effects. We will record in primary visual cortex (V1) because it provides a solid background on which to base our experiments. We will conduct parallel recordings in extrastriate area V2 because previous work suggests that it may have different sensitivity to contextual information. The experimental results will validate and guide the modeling framework. Our approach will be a significant advance over previous scene statistics modeling work that has focused on explaining limited contextual physiology data for simple stimuli such as gratings, and will for the first time make full use of the power of scene statistics to answer a fundamental question. Most importantly, our work will make significant strides in elucidating how cortical circuits process natural scenes, within a theoretical framework that provides both predictive and explanatory power. Collaboration: The project will involve a collaborative effort between two young investigators with expertise in computational visual neuroscience and systems physiology; it combines state-ofthe- art algorithms from computational vision and technology for recording populations of neurons in early visual cortex. We will achieve our goal by closely integrating theory and model development with electrophysiological experiments, an approach fostered by the proximity of the two investigators. Broader Impacts: This proposal is expected to have broad impacts in five main areas. First, the work will have broad impact for basic, biomedical, and applied disciplines, including: studying other sensory systems under natural input; building superior visual aids; designing artificial systems; and advancing image and signal processing. Second, the data and stimuli will be made broadly available to the community through the CRCNS data sharing website. Third, the project will be used to train and mentor postdoctoral fellows to become independent research scientists. Fourth, the project will for the first time introduce students at Albert Einstein to the combination of theoretical and experimental approaches for solving fundamental questions in neuroscience. Finally, the project will be used as part of an outreach effort to expose local underrepresented high school students in the Bronx to exciting scientific research.