Spatial Summation and Dynamics of Visual Neurons

视觉神经元的空间求和和动力学

• 批准号: 6801157
• 负责人: ROBERT M SHAPLEY
• 金额: $ 37.82万
• 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 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6801157
• 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; visual perception; visual stimulus

DESCRIPTION (provided by applicant): The overall goal of this project is to understand the function of cortical circuitry in macaque monkey primary visual cortex Vi, and how it contributes to visual perception. Experiments are designed to test models of the cortex. The crucial question in most models is, what is the nature of cortico-cortical interaction? I will pursue the following aims. 1. To measure the dependence of steady-state orientation selectivity on contrast. We have preliminary data that indicate there is some effect of contrast on selectivity for sine-grating. Also contrast invariance (or its absence) is crucially important for theories of orientation selectivity. Furthermore, I will measure orientation selectivity for flashed bars and edges on the same cells as for sine gratings, and also measure effects of contrast with these stimuli.2. To measure the dependence of orientation selectivity dynamics on contrast and context. Measuring orientation-tuning dynamics as a function of contrast will provide further strong constraints on models of orientation selectivity. Also, we will measure orientation dynamics for contours embedded (vs. not embedded) in visual objects, to probe whether perception-related signals are measurable in Vi with this technique. The dynamics of responses to step increases in contrast at preferred orientations will also be measured and compared with the reverse correlation results.3. To measure cross-orientation inhibition in plaids (and other 2D patterns). Another way to test whether or not there is recurrent interaction between orientation-tuned elements is to use a plaid stimulus (Wallach, 1935; Adelson and Movshon, 1982). In the particular plaid patterns I will use, the two 1-D components are near each other in orientation (say 20-300), but differ in temporal frequency.4. To examine the effect of random or natural-image backgrounds or other context on orientation selectivity. I want to measure tuning curves of stimuli placed on modulated backgrounds that will tend to elevate the cell's spike rate and get it away from threshold. There is the added question; will natural image backgrounds have a different effect from that of random noise? Steady state orientation tuning curves, as well as step responses, will be measured on these different backgrounds and compared with the dynamics from reverse correlation experiments on the same neurons.

描述（由申请人提供）：该项目的总体目标是了解猕猴主视觉皮层VI中皮质电路的功能，以及它如何促进视觉感知。实验旨在测试皮层的模型。在大多数模型中，至关重要的问题是，皮质皮质相互作用的本质是什么？我将追求以下目标。 1。衡量稳态方向选择性对比度的依赖性。我们有初步数据表明对正弦晶状体的选择性有一些对比的影响。对比度（或其缺席）也对方向选择性理论至关重要。此外，我将测量与正弦光栅相同细胞上闪烁的条和边缘的方向选择性，并测量与这些刺激的对比的影响2。测量方向选择性动力学对对比和上下文的依赖性。测量方向调节动力学作为对比度的函数将为方向选择性模型提供进一步的强大限制。同样，我们将测量视觉对象中嵌入的轮廓（与未嵌入）轮廓的方向动力学，以探测使用此技术在VI中是否可以测量与感知相关的信号。在首选方向上对比对比度的响应的动力学也将被测量，并将其与反向相关结果进行比较。3。测量格子（和其他2D模式）中的跨取向抑制。测试方向调节元素之间是否存在复发相互作用的另一种方法是使用格子刺激（Wallach，1935; Adelson and Movshon，1982）。在我要使用的特定格子图案中，两个1-D组件的方向彼此接近（例如20-300），但时间频率有所不同。4。检查随机或自然图像背景或其他上下文对方向选择性的影响。我想测量放置在调制背景上的刺激的调谐曲线，这些刺激趋向于提高细胞的尖峰速率并将其远离阈值。还有一个额外的问题；自然图像背景会与随机噪声不同吗？稳态取向调谐曲线以及步骤响应将在这些不同的背景下进行测量，并将其与同一神经元上反向相关实验的动力学进行比较。