MSM: Collaborative Research: Cortical Processing Across Multiple Scales

MSM：协作研究：跨多个尺度的皮层处理

• 批准号: 0506287
• 负责人: Gregor Kovacic
• 金额: --
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0506287&HistoricalAwards=false
• 关键词: MSM; Collaborative; Research; Cortical; Processing

The project's goal is to create theoretical and computational tools to explain "brain computations" taking place in the mammalian primary visual cortex, the first location along the visual pathway in which individual nerve cells (neurons) "recognize" elementary features of the visual scene, such as pattern orientation. A large-scale, biologically realistic numerical neuronal network model will be developed for simulating how the primary visual cortex acts as a "computer" to make this feature recognition possible, and used to simulate a patch of the primary visual cortex of about 5 millimeters by 5 millimeters in size and containing close to a million neurons. Coarse-grained representations of the primary visual cortex will also be developed, which treat it as a continuum rather than a set of individual neurons and incorporate the statistics of a multitude of experimental runs in the description instead of just one, thus eliminating the need for large numbers of simulations. Finally, hybrid representations will be developed, in which select groups of neurons are described by a large-scale neuronal model, while others are described by a bulk coarse-grained representation. Such representations appear particularly promising for simulating realistic neuronal processing of stimuli in yet larger portions of the brain.The models and software will be validated and showcased on two striking examples of observed processing in the primary visual cortex: patterns of spontaneous cortical activity and motion illusions. The former were seen to encompass collective behavior of thousands of neurons on millimeter scales, and appear to get activated in areas in which neurons prefer the same orientation. In a popular motion illusion, showing a small square immediately followed by a long bar makes the square appear as if it is "growing" to become the bar. A physiological mechanism for this illusion was observed experimentally to be actual cortical activity corresponding to the perceived "growth" of the square into the bar, similar to that caused by real motion. One intended task for the software and models is to explain such mechanisms governing the dynamical behavior of the primary visual cortex and underlying these and other cortical phenomena.How information is processed in the visual cortex is one of the most challenging questions in neuroscience. The proposed study of spatiotemporal activity over large scales, using a very large computational model of the primary visual cortex as well as coarse-grained theoretical methods, addresses an urgent need for scale-up in modern neuroscience, which is the theoretical complement to the recent development of multi-mode, large-scale experimental methods. The models and software developed in this project are aimed at obtaining qualitatively and quantitatively realistic explanations of the biological mechanisms that underlie neuronal computations in the primary visual cortex, and possibly other cortical areas. The software will be made readily accessible to a large group of researchers across the neurosciences, with the aim that its results will help science make significant inroads into theoretical understanding of the mechanisms of sensory perception and possibly other brain functions.

该项目的目标是创建理论和计算工具，以解释在哺乳动物主视觉皮层中发生的“大脑计算”，这是沿着视觉途径的第一个位置，其中单个神经细胞（神经元）“识别“视觉场景的基本特征”，例如模式方向。 将开发一个大规模的，生物学上现实的数值神经元网络模型，以模拟主视觉皮层如何充当“计算机”，以使此功能识别成为可能，并用于模拟大约5毫米的主要视觉皮层的斑块。 5毫米的大小，包含近一百万个神经元。 也将开发主要视觉皮层的粗粒表示，将其视为连续性而不是一组单个神经元，并在描述中纳入了许多实验性运行的统计数据，而不仅仅是一个实验性运行，从而消除了对需要的需求大量模拟。最后，将开发杂种表示，其中大规模神经元模型描述了某些神经元组，而其他神经元则用大量的粗粒表示。 这种表示似乎是在大脑的较大部分中模拟刺激的现实神经元处理的特别有希望。模型和软件将在主要视觉皮层中观察到的两个引人注目的处理示例进行验证和展示：自发性皮层活动和运动幻象的模式。 看到前者在毫米尺度上包含数千个神经元的集体行为，并且似乎在神经元更喜欢相同方向的区域被激活。 在流行的运动幻觉中，立即显示一个小正方形，然后是一个长条，使得正方形看起来好像正在“成长”成为栏。 在实验上观察到了这种幻觉的生理机制，是对应于正方形进入条形的“生长”的实际皮质活性，类似于由实际运动引起的。 软件和模型的一项预期任务是解释管理主要视觉皮层的动态行为并在这些和其他皮质现象的基础的机制中。如何在视觉皮层中处理信息是神经科学中最具挑战性的问题之一。 提出的对大尺度上时空活动的研究，使用主要视觉皮层的非常大的计算模型以及粗粒度的理论方法，它涉及现代神经科学的迫切需求，这是对最近的理论补充多模式大规模实验方法的开发。 该项目中开发的模型和软件旨在在定性和定量的现实中获取对主要视觉皮质和可能其他皮质区域中神经元计算的生物学机制的解释。该软件将很容易访问整个神经科学的大量研究人员，其目的将有助于科学对感官感知机制以及可能的其他大脑功能的理论理解。