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.

这个提议是关于猕猴的纹状皮层的： 确定它如何通过方向表示空间信息 通过测量动力学来调整和二维空间相互作用 皮层神经元和单细胞神经网络 电生理学。 方向调整动态。 我们需要延长 我们对方向动力学的初步测量：首先，使用 更小和更大的刺激区域，看看动态有多大 由于超柱内的局部电路相互作用，以及有多少 远程连接；其次计算刺激的程度 过去非线性调制响应，以及如何这样 非线性影响方向调整。 对比。我将测量 因为我们知道对比度对观察到的方向动态的影响 V1 反应在低对比度下会减慢。 测量值较低 对比将使我们能够更好地解决影响 方向调整的时间演化。 孔径前馈模型 意味着当测试图案是时方向调整应该降级 通过非常小的孔径观察，但反馈模型可以保留 他们的调音。 基于这个想法，通过测量方向调整 不同尺寸的光圈是重中之重。 这里的关键是 在感受野子区域的空间尺度上使用孔径（<1 度），测试局部空间总和占多少 方向调整。 感受野我们将使用子空间反转 相关方法来表征二维时空敏感性 V1 神经元，并研究对比对二维时空的影响 感受野。 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，但它们可能以以下时间模式进行编码 响应而不仅仅是尖峰计数。 在单细胞和 视觉诱发电位（VEP），我们将测量时空 对感受野中间的斑块的响应动态 不同种类背景的存在：空间均匀， 黑色，或中央斑块图案的空间延伸。 我会 寻求与相关的响应动态的变化 场景的图形/地面组织。 我们也会寻找 嵌入二阶响应中的上下文效应。