Nonlinear Dynamics of the Primary Visual Cortex

初级视觉皮层的非线性动力学

• 批准号: 0211655
• 负责人: David McLaughlin
• 金额: $ 20.38万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0211655&HistoricalAwards=false
• 关键词: Nonlinear; Dynamics; Primary; Visual; Cortex

McLaughlin0211655 The investigator and colleagues have been developing abiologically constrained large-scale computational model of the"front-end" of the cortical visual system -- the primary visualcortex (V1). To date, their work has focused upon localproperties of individual cells within the large-scale network --properties such as orientation selectivity and simple vs complexcellular dynamics. In this project, they scale up to a moreglobal model of V1, reaching scales large enough to study someelementary optical illusions of psychology and psychophysics.This involves several square millimeters of lateral corticalarea, together with a multi-layered architecture -- with emphasisgiven to cortical dynamics. First, a "coarse-grained mixedrepresentation" is derived mathematically and tested numerically-- a representation that combines spatially coarse-grained(local) mean firing rates, representing local background corticaloperating points, with an idealized representation of asub-network of individual point neurons embedded within thisbackground and retaining the detailed firing patterns ofindividual neurons. These two components interact with eachother -- with the coarse-grained local operating pointsinfluencing the responses of the individual neurons, and viceversa. Second, the global mixed representation is used to studyspecific dynamical phenomena in visual cortical processing: (i)the layer-specific "dynamics of orientation selectivity" (asmeasured by reverse time correlation methods); and later (ii)"bistability in figure-ground assignments" (as detected inpsychology and psychophysics experiments). In both cases, thephenomena involve extensive lateral regions of V1, its layeredstructure, and (likely in the case of figure-ground assignment)other cortical regions. And in both cases the work involvesclose interaction with the experimental work of neural scientistRobert Shapley. Today, through new biological experiments combined with thepower of modern scientific computation, scientists and appliedmathematicians are making significant strides towardunderstanding the human brain. Visual perception and the corticalprocessing of visual information provide important startingpoints. By focusing upon the "front end" of the cortical visualsystem, McLaughlin and his colleagues develop computationalmodels of the visual cortex that are strongly constrained bybiological experiments. In this project the investigatorsdevelop computationally efficient numerical methods that permitscale-up of the models to global representations of the primaryvisual cortex -- reaching cortical scales large enough to studysome elementary optical illusions of psychology. This workrequires the direct interaction of applied mathematicians,computational scientists, and neural scientists -- and involvestheoretical, computational, and experimental components.

McLaughlin0211655研究者及其同事一直在开发皮质视觉系统“前端”的物质约束的大规模计算模型 - 主要的静visualcortex（V1）。 迄今为止，他们的工作集中在大规模网络中各个单元格的局部特性 - 方向选择性和简单vs络合细胞动力学之类的专业。 在这个项目中，它们扩展到了V1的近全球模型，达到足够大的尺度，可以研究心理学和心理物理学的某种元素的光学幻象。这涉及几个平方毫米的侧面皮质核心，并强调了对皮质动力学的多重体系结构。 First, a "coarse-grained mixedrepresentation" is derived mathematically and tested numerically-- a representation that combines spatially coarse-grained(local) mean firing rates, representing local background corticaloperating points, with an idealized representation of asub-network of individual point neurons embedded within thisbackground and retaining the detailed firing patterns ofindividual neurons. 这两个组件与彼此相互作用 - 与粗粒的局部操作点相互作用，从而使单个神经元的响应和Viceversa相互作用。 其次，全局混合表示在视觉皮质处理中使用特定的动力学现象：（i）特定层特异性的“方向选择性的动力学”（通过反向时间相关方法来衡量）；后来（ii）“在图 - 地面分配中的双重性”（如发现的心理学和心理物理学实验）。 在这两种情况下，苯甲瘤均涉及V1的广泛横向区域，其分层结构，并且（可能在图形分配的情况下）其他皮质区域。 在这两种情况下，这项工作都涉及与神经科学家Shapley的实验工作相互作用。 如今，通过新的生物学实验与现代科学计算的能力相结合，科学家和应用中的分子者正在迈向理解人脑的重要步伐。 视觉感知和视觉信息的皮质过程提供了重要的起点。 通过关注皮质视觉系统的“前端”，McLaughlin及其同事开发了视觉皮层的计算模型，这些模型受到了强烈约束的拜生物学实验。 在该项目中，研究人员的计算有效的数值方法允许模型将模型划定为主要视觉皮层的全球表示形式 - 达到足够大的皮质尺度，可以研究心理学的基本光学错觉。 这使应用数学家，计算科学家和神经科学家的直接相互作用以及涉及介绍，计算和实验组成部分。