Columnar Organization of Surface vs. Border Information in Human Areas V2 and V3

人类区域 V2 和 V3 中表面与边界信息的柱状组织

基本信息

批准号：
9153186
负责人：
ROGER B TOOTELL
金额：
$ 46.18万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-30 至 2019-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9153186
关键词：
Accounting Affect Amblyopia Animals Architecture Brain Brain Diseases Cerebral cortex Clinical Color Color Visions Cortical Column Crowding Data Depth Perception Disease Eye Functional Magnetic Resonance Imaging Geometry Human Image Imaging Techniques Length Link Location Maps Measurement Measures Meridians Motion Nature Neurons Pattern Perception Population Process Property Publishing Radial Reporting Research Resolution Role Shapes Staging Stimulus Stream Surface Surface Properties Syndrome System Testing Textbooks Texture Thick Variant Vision Vision Disparity Visual Visual Cortex Visual Fields Work abstracting area V2 area V3 area striata base cortex mapping extrastriate visual cortex information processing luminance neuron component nonhuman primate receptive field response retinotopic segregation stereoscopic visual information visual stimulus

项目摘要

Project Summary/Abstract More than a third of human cerebral cortex responds to visual information, which enters cortex through primary visual cortex (V1). Accordingly, much is known about V1 processing. However, much less is known about information processing in the `next' cortical area (V2), and even less is known about higher area V3. In animal studies of V2, one key to understanding information processing is that different types of stimulus features are processed ~independently in segregated `stripes' of cortical columns. One set of columnar stripes responds selectively to variations in color, a surface property. Another set of columns responds best to variations in boundaries based on stereoscopic (`3D') stimuli (thus the latter research can clarify mechanisms underlying amblyopia). Study of such columns can reveal fundamental responses in the component neurons. Previously, it has been unknown whether such functional stripes/columns exist in humans. Conventional functional magnetic resonance imaging (fMRI) techniques cannot spatially resolve such columns, which are quite small. By using a specialized fMRI approach (7T, 1 mm3), here we successfully demonstrated (and have begun analyzing) such columns and stripes in human areas V2 and V3. Beyond simply imaging such columns, we propose to test a new hypothesis: early visual cortex processes boundaries vs. surface features, in two parallel streams, within thin and thick stripes (respectively) in V2. We also test whether that surface-vs.- boundary information is then passed forward to segregated columns in V3. If confirmed, this hypothesis will clarify (and help unify) the diverse existing data about the nature of functional processing in early visual cortex. Aim 1 will test our hypothesis by presenting different types of stimulus boundaries or surface properties, testing for correspondingly higher responses in thick or thin stripes, respectively. Each of five sub-aims will isolate and test responses to boundaries defined by differences in either: binocular disparity (sub-aim 1.1), or direction of motion (1.2), texture (1.3), color (1.4), or luminance (1.5). Aim 2 tests the conclusions from Aim 1 in a complementary way, by presenting stimuli that include only a single boundary, in each quadrant of the visual field, and in the corresponding cortical map. Aims 3.1 and 3.2 will test for higher activity in retinotopically-predicted subregions in thick stripes (and related V3 columns) due to inferred or illusory contours. The stimulus used in aim 3.3 predicts a shift in activity between the thin vs. thick stripe systems, produced by retinotopically specific colored surfaces- vs. boundaries, respectively. Different points in visual space (either surfaces or boundaries) are mapped onto the cortical surface, a property known as `retinotopic' mapping. Thus the columns (aim 1) co-exist with maps of retinotopy. However It is not known how these two maps accommodate each other at the spatial resolution of columns. Aim 3 will clarify whether thin vs. thick stripes (and related V3 columns) have duplicated retinotopic maps (sub-aim 3.1), or specific retinotopic `gaps' (3.2), or smaller vs. greater retinotopic spread, respectively.

项目概要/摘要超过三分之一的人类大脑皮层对视觉信息做出反应，视觉信息通过初级视觉皮层（V1）。因此，人们对 V1 处理了解很多。然而，人们知道的却少之又少关于“下一个”皮质区域（V2）的信息处理，我们对更高区域 V3 知之甚少。在 V2 的动物研究表明，理解信息处理的关键之一是不同类型的刺激特征在皮质柱的隔离“条纹”中独立处理。一组柱状条纹有选择地响应颜色（一种表面特性）的变化。另一组列的响应最好基于立体（“3D”）刺激的边界变化（因此后面的研究可以阐明机制潜在弱视）。对此类柱的研究可以揭示组成神经元的基本反应。此前，尚不清楚人类是否存在这种功能性条纹/柱。传统的功能磁共振成像 (fMRI) 技术无法在空间上解析此类柱，这些柱是相当小。通过使用专门的功能磁共振成像方法（7T，1 mm3），我们在这里成功地演示了（并且已经开始分析）人类区域 V2 和 V3 中的此类柱状和条纹。除了简单地对此类柱进行成像之外，我们建议测试一个新的假设：早期视觉皮层处理边界与表面特征，分为两种平行流，分别在 V2 中的细条纹和粗条纹内。我们还测试了表面与- 然后边界信息被转发到 V3 中的隔离列。如果这一假设得到证实，澄清（并帮助统一）有关早期视觉皮层功能处理性质的各种现有数据。目标 1 将通过呈现不同类型的刺激边界或表面特性来检验我们的假设，分别测试粗条纹或细条纹中相应较高的响应。五个子目标中的每一个都将隔离并测试对由以下差异定义的边界的响应：双眼视差（子目标 1.1），或运动方向 (1.2)、纹理 (1.3)、颜色 (1.4) 或亮度 (1.5)。目标 2 以互补的方式测试目标 1 的结论，即提供仅包含单一边界，位于视野的每个象限以及相应的皮质图中。目标 3.1 和 3.2 将测试粗条纹（和相关 V3 列）中视网膜局部预测子区域的较高活性推断或虚幻的轮廓。目标 3.3 中使用的刺激预测瘦人和瘦人之间的活动发生转变。粗条纹系统，分别由视网膜特定的彩色表面与边界产生。视觉空间中的不同点（表面或边界）被映射到皮质表面，称为“视网膜主题”映射的属性。因此，列（目标 1）与视网膜局部图共存。然而目前尚不清楚这两个地图如何在列的空间分辨率下相互适应。目标3将澄清细条纹与粗条纹（以及相关的 V3 列）是否具有重复的视网膜专题图（子目标 3.1），或特定的视网膜专题“间隙”（3.2），或较小与较大的视网膜专题扩散。