SPATIAL SUMMATION AND DYNAMICS OF VISUAL NEURONS

视觉神经元的空间求和和动力学

• 批准号: 6178384
• 负责人: ROBERT M SHAPLEY
• 金额: $ 32.31万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 2002-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6178384
• 关键词: Macaca fascicularis; behavioral /social science research tag; brightness discrimination; cell cell interaction; color visions; electrodes; electrophysiology; evoked potentials; form /pattern perception; histology; mathematical model; motion perception; neural information processing; orientation; space perception; stimulus /response; visual cortex; visual fields

This proposal is about the macaque monkey's striate cortex: determining how it represents spatial information though orientation tuning and 2-D spatial interactions by measuring the dynamics of cortical neurons and neural networks with single cell electrophysiology. Orientation tuning dynamics. We need to extend our preliminary measurements of orientation dynamics: First, to use smaller and larger stimulus areas to see how much of the dynamics is due to local circuit interactions within hypercolums, and how much to long-range connections; Second to calculate to what extent a stimulus in the past nonlinearly modulates the response, and how such nonlinearities affect orientation tuning. Contrast. I will measure the effect of contrast on the observed orientation dynamics since we know that V1 responses are slowed at low contrast. Measurements at lower contrast will enable us to resolve better the processes that affect the time evolution of orientation tuning. Apertures Feedforward models imply that orientation tuning should degrade when the test patterns are viewed through very small apertures, but feedback models can retain their tuning. Based on this idea, measuring orientation tuning through different-sized apertures is a high priority. The key here will be to use apertures on the spatial scale of receptive field subregions (<1 degree), to test how much local spatial summation accounts for orientation tuning. Receptive fields We will use the subspace reverse correlation method to characterize the 2-D spatiotemporal sensitivity of V1 neurons, and to study contrast effects on the 2-D spatiotemporal receptive fields. Contest, and boundary completion. Long distance effects on cortical responses, due to image context effects such as boundary completion and figure/ground segregation, may be significant in V1, but they may be encoded in the temporal pattern of the response rather than just in the spike count. In single cells and visual evoked potentials (VEPs), we will measure the spatiotemporal dynamics of response to a patch in the middle of the receptive field in the presence of different kinds of backgrounds: spatially uniform, black, or a spatial extension of the pattern in the central patch. I will be seeking a change in the dynamics of the response the is tied to the figure/ground organization of the scene. We also will search for context effects embedded in 2nd order responses.

该提议是关于猕猴的条纹皮质的： 确定其表示空间信息的方式 通过测量的动力学来调整和二维空间相互作用 具有单细胞的皮质神经元和神经网络 电生理学。 方向调整动力学。 我们需要扩展 我们的定向动力学的初步测量：首先使用 越来越大的刺激区域以查看多少动态 由于局部电路相互作用，高圆柱以及多少 远程连接；其次计算刺激的程度 过去，非线性调节响应，以及如何这样 非线性影响方向调整。 对比。我将测量 对比度对观察到的方向动态的影响，因为我们知道 在低对比度下，V1响应放慢了速度。 较低的测量 对比将使我们能够更好地解决影响该过程的过程 定向调整的时间演变。 光圈进料模型 暗示测试模式为 通过非常小的光圈查看，但反馈模型可以保留 他们的调整。 基于这个想法，测量取向调整 不同尺寸的孔径是高度优先级。 这里的关键是 在接收场子区域的空间尺度上使用光圈（<1 学位），测试本地空间求和多少 方向调整。 接收场我们将使用子空间反向 相关方法是表征2-D时空灵敏度的 V1神经元，研究对二维时空的对比影响 接受场。 竞赛和边界完成。 长途 由于图像上下文效应，例如 边界完成和图形/地面隔离可能是 在V1中很重要，但它们可能以时间模式进行编码 响应，而不仅仅是在尖峰计数中。 在单细胞中， 视觉诱发电位（VEP），我们将测量时空 在接受场中间对斑块的反应动力学的动力学 不同种类的背景的存在：在空间上均匀， 黑色，或中央贴片中图案的空间扩展。 我会 寻求改变响应动力的改变 现场的图/地面组织。 我们还将搜索 上下文效果嵌入了第二阶响应中。