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

• 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
• 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

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.

项目摘要/摘要 超过三分之一的人类大脑皮层响应视觉信息，该信息通过 一级视觉皮层（V1）。因此，关于V1处理知之甚少。但是，少得多 关于“下一个”皮质区域（v2）中的信息处理，甚至对更高的区域V3的了解更少。在 V2的动物研究，了解信息处理的一个关键是不同类型的刺激 特征是在皮质柱的隔离“条纹”中独立处理的。一组柱状条纹 选择性响应颜色的变化，即表面特性。另一组列对 基于立体（“ 3D”）刺激的边界的变化（后面的研究可以阐明机制 弱视的基础）。对此类列的研究可以揭示组件神经元中的基本反应。 以前，尚不清楚人类中是否存在此类功能条纹/柱。传统的 功能磁共振成像（FMRI）技术无法在空间上解析此类列， 很小。通过使用专门的fMRI方法（7t，1 mm3），我们在这里成功证明了（并且有 开始分析人类区域V2和V3的这些柱和条纹。除了简单地想象这样的列， 我们建议检验一个新的假设：早期视觉皮层过程边界与表面特征，在两个 平行流，分别在V2中的薄和厚条纹中。我们还测试了表面vs.-是否 然后将边界信息传递给V3中的隔离列。如果确认，该假设将 澄清（并帮助统一）有关早期视觉皮层功能处理性质的不同现有数据。 AIM 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， 测试分别在厚或薄条纹中相应较高的响应。五个子iam中的每一个 分离和测试对由差异定义的边界的响应：双眼差（sub-aim 1.1）或 运动方向（1.2），纹理（1.3），颜色（1.4）或亮度（1.5）。 AIM 2通过呈现仅包括一个刺激来测试AIM 1的结论 单个边界，在视野的每个象限中以及相应的皮质图中。目标3.1和3.2 将测试较厚条纹（及相关V3列）的视网膜预测子区域的较高活性 推断或虚幻的轮廓。 AIM 3.3中使用的刺激预测了薄V之间的活性变化。 厚条纹系统，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，A 属性称为“视网膜”映射。因此，列（AIM 1）与视网膜图共存。然而 尚不清楚这两个地图如何在列的空间分辨率下相互容纳。目标3意志 澄清薄与厚条纹（及相关V3列）是否具有重复的视网膜图（Sub-aim 3.1），， 或特定的视网膜“差距”（3.2）或较小的视网膜扩散。