Neural Computations In Visual Cortex

视觉皮层的神经计算

• 批准号: 7236581
• 负责人: Jonathan D Victor
• 金额: $ 40.78万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7236581
• 关键词: Characteristics; Code; Complex; Elements; Equilibrium; Fire - disasters; Frequencies; Funding; Goals; Image; Investigation; Lead; Localized; Modeling; Nature; Neurons; Noise; Operative Surgical Procedures; Pattern; Pilot Projects; Play; Population; Rate; Research; Role; Spottings; Standards of Weights and Measures; Stimulus; Structure; Time; V1 neuron; Vertebral column; Vision; Visual; Visual Cortex; area striata; falls; novel; receptive field; relating to nervous system; research study; response; tool; two-dimensional; visual information; visual stimulus

DESCRIPTION (provided by applicant): We aim to advance our understanding of the nature of the operations performed by primary visual cortex, and how these operations are carried out. The research plan is organized around two basic questions. A. Are the spatial computations performed by neurons in V1 adequately described by oriented receptive fields, simple nonlinearities, and gain controls, or, conversely, do more complex spatial operations play an important role? B. Can firing rate of a local population be considered the main carrier of visual information, or, conversely, is the fine structure of neural activity (across time or across a local population) also important? Question A is motivated by growing experimental evidence that the operations performed by V 1 neurons are indeed complex. The experimental strategy described here uses new stimuli, precisely balanced in space and spatial frequency - in contrast to traditional stimuli, that are highly localized in space but broad in spatial frequency (e.g., spots and bars), or extended in space but highly localized in spatial frequency (e.g., gratings). Pilot studies using the new stimuli demonstrate response patterns not anticipated from standard models - including shifts in the balance of linear and nonlinear influences, and shifts in orientation tuning. The stimulus set is a hierarchy of patterns that are progressively less restricted in their combined space bandwidth aperture. The patterns that are the most restricted in space-bandwidth aperture are Gaussians and profiles that resemble edges and lines. As the space-bandwidth aperture is broadened, intrinsically two-dimensional patterns and "non-Cartesian" patterns emerge, thus suggesting that our approach will also be useful beyond V1. Question B builds on our identification of the statistical features of the fine structure of neural activity that are reliably correlated with visual stimuli. We now propose to determine whether these features indeed influence the activity of downstream neurons. Our approach relies on a combination of multiple-neuron recordings via tetrodes, and experimental results and analytic tools that emerged during the previous funding period. Together, these investigations will advance the understanding of neural computations that lead to extraction of features and objects from the visual image.

描述（由申请人提供）：我们旨在提高对主要视觉皮层执行操作性质的理解，以及如何执行这些操作。研究计划围绕两个基本问题组织。答：神经元在V1中执行的空间计算是否通过定向的接受场，简单的非线性和增益控制措施充分描述，还是相反，更复杂的空间操作起着重要作用？ B.当地人口的发射速率是否被认为是视觉信息的主要载体，或者相反，神经活动的精细结构（跨时间或跨当地人口）也很重要吗？问题A是由于越来越多的实验证据激发了V 1神经元的操作确实很复杂。此处描述的实验策略使用了新的刺激，这是在空间和空间频率上精确平衡的 - 与传统刺激相比，这些刺激在空间中高度局部，但在空间频率（例如，斑点和条形）中具有广泛的位置，或在空间中扩展，但在空间频率上进行了高度定位（例如，光洁度）。使用新刺激的试验研究表明，标准模型未预期的响应模式 - 包括线性和非线性影响平衡的变化以及方向调整的变化。刺激集是模式的层次结构，在其组合空间带宽光圈中逐渐限制。在太空带宽孔径中最受限制的模式是高斯和类似边缘和线条的轮廓。随着空间宽度的孔径被扩展，本质上是二维模式和“非牙犯”模式出现的，因此表明我们的方法在V1之外也将是有用的。问题B建立在我们对与视觉刺激可靠相关的神经活动精细结构的统计特征的识别。现在，我们建议确定这些特征是否确实影响下游神经元的活性。我们的方法依赖于通过四极管通过多个神经元记录的组合，以及在上一个资金期间出现的实验结果和分析工具。总之，这些研究将提高对神经计算的理解，从而导致从视觉图像中提取特征和对象。