MECHANISMS OF VISUAL CONTEXT EFFECTS IN VISUAL CORTEX

视觉皮层中视觉情境效应的机制

• 批准号: 6350890
• 负责人: JONATHAN B LEVITT
• 金额: $ 20.2万
• 依托单位: CITY COLLEGE OF NEW YORK
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6350890
• 关键词: Macaca fascicularis; Macaca mulatta; electrophysiology; ferrets; microelectrodes; neuroanatomy; neurons; space perception; synapses; visual cortex; visual fields; visual stimulus

Visual stimuli at locations beyond the classical receptive field (the area of the visual field from which responses can be evoked) can have profound effects on the selectivity and magnitude of neuronal responses in the visual cortex, even when these stimuli do not themselves evoke responses. It is generally assumed that intrinsic anatomical connections underlie these modulatory effects. Understanding how cortical neuron responses are shaped by such modulatory effects is important for understanding the role of cortical organization in determining cortical function, and in how the visual areas of the brain process complex real- world scenes. In this study we will clarify how neuronal responses in visual cortex are shaped by the spatial distribution of visual stimuli, and we will elucidate the anatomical substrates that link different points on the cortex (and therefore different spatial locations). This will therefore permit a direct test of whether local cortical connections do in fact underlie these modulatory surround effects. 1) In electrophysiological and neuroanatomical experiments in adult monkeys and ferrets, we will test whether the spatial extent and topography of response suppression or enhancement from beyond the classical receptive field can be accounted for by the distribution of local horizontal or cortical feedback connections within primary visual cortex (V1) and V2. 2) In electrophysiological studies in adult monkeys and ferrets, we will explore the stimulus specificity of response modulation from beyond the classical receptive field in V1 and V2. We will focus on V1 as the gateway to other cortical visual areas, but will also examine V2 to illuminate how general the properties and function of these modulatory effects are to all cortical visual areas. 3) In developmental studies in ferrets, we will systematically compare, across a large range of postnatal ages, the development of the modulatory surround effects to that of the responses in the classical receptive field, and to the refinement of intrinsic and extrinsic connections in V1. This will allow us to compare the developmental refinement of the modulatory effects to classical receptive field properties, and to further test whether intrinsic connections can underlie surround modulation. Comparison of details of the selectivity and spatial extent of different anatomical circuits with similar details from physiological investigations will provide information critical to an understanding of which anatomical circuits underlie particular functions, and in how neuronal function and connectivity underlie visual performance. This is a fundamental question in understanding how the cerebral cortex works, both in vision and in higher cognitive function.

在经典接受场（可以唤起响应的视野区域）以外的位置的视觉刺激可能会对视觉皮层中神经元反应的选择性和幅度产生深远的影响，即使这些刺激本身并不唤起反应。 通常认为，内在的解剖联系是这些调节作用的基础。 了解这种调节效应如何影响皮质神经元的反应对于理解皮质组织在确定皮质功能以及大脑过程中的视觉区域复杂现实世界场景中的作用至关重要。 在这项研究中，我们将阐明视觉皮层中的神经元反应如何通过视觉刺激的空间分布来塑造，我们将阐明将皮质上不同点联系起来的解剖学底物（因此，因此不同的空间位置）。 因此，这将允许直接测试局部皮质连接是否实际上是这些调节环绕效应的基础。 1）在成年猴子和雪貂的电生理和神经解剖学实验中，我们将测试是否可以通过分布主要的视觉皮层（V1）和V2内的局部水平反馈连接来解释经典接受场的空间范围和抑制或增强的地形。 2）在成年猴子和雪貂的电生理研究中，我们将探讨V1和V2中经典接受​​场的反应调节的刺激特异性。 我们将专注于V1作为通往其他皮质视觉区域的门户，但还将检查V2，以阐明这些调节效应对所有皮质视觉区域的概述和功能的一般性和功能。 3）在雪貂的发育研究中，我们将系统地比较出产后年龄，调节周围效应与经典接受场中的反应的发展以及V1中内在和外在联系的完善。 这将使我们能够将调制效应的发展改进与经典的接收场特性进行比较，并进一步测试固有连接是否可以构成环绕声调制的基础。比较不同解剖回路的选择性和空间范围的细节与生理研究的相似细节将为理解哪些特定功能以及神经元功能和连接性的视觉表现的方式提供至关重要的信息。 这是理解大脑皮层在视觉和更高认知功能方面的工作原理的基本问题。