Functions and interactions of brain areas hMT+ and hV4 in the human visual system

人类视觉系统中大脑区域 hMT 和 hV4 的功能和相互作用

• 批准号: RGPIN-2016-03824
• 负责人: Mullen, Kathy
• 金额: $ 2.55万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=660404
• 关键词: Functions; interactions; brain; areas; hMT+

The objective is to investigate the modularity of the human brain for the visual attributes of color, form and motion perception. Although these fundamental aspects of the visual image appear perceptually integrated, accumulated evidence suggests that they are processed separately within different, specialized areas of the brain. Two key brain areas are thought to be fundamental for the processing of these attributes: hMT+ and hV4. The human MT complex (hMT+) is traditionally considered to be part of the dorsal pathway, despite its more lateral location, and is known to be involved in motion perception, whereas hV4 is part of the ventral pathway and is thought to be involved in the processing of shape and color. Much of what we know about these two areas has been acquired from work done on non-human primates. Here we aim to test hypotheses about their functions in human vision by selectively and temporarily impairing the responses of each using a brain stimulation technique, rTMS. If stimulation of the targeted brain area results in a consistent impairment (or improvement) of a specific visual task, it is likely that the brain area is functionally involved. After localizing the relevant brain areas using fMRI, we determine the effect of brain stimulation of each area on the performance of specific visual tasks. Each task is designed to test a specialized visual function relating to motion, form or color perception. The proposed program aims to provide a comprehensive investigation of the functional roles of areas hMT+ and hV4 in vision, but also to determine the functional overlap and interactions between the areas.***The program addresses core questions about the modularity of processing of visual information in the human brain. The proposal is high impact since very little known about the role of hV4 in the human brain. This area has rarely investigated with rTMS, yet the approach opens up important opportunities for understanding its role in human vision. Furthermore, the experiments specifically address the overlap of function between two key areas with the aim of understanding the common functions of the dorsal and ventral pathways rather than simply how visual areas operate as separate modules.***This program represents a new direction of research rather than a simple continuation of my previously supported NSERC program. The TMS approach combines the understanding of color, form and motion processing that I have developed in my lab over the past decade from both psychophysical and fMRI experiments into a program of research that directly addresses the function of two key visual areas of the human brain.**

目的是研究人脑对于颜色、形状和运动感知等视觉属性的模块化。尽管视觉图像的这些基本方面在感知上似乎是整合的，但积累的证据表明它们是在大脑的不同专门区域中单独处理的。两个关键的大脑区域被认为是处理这些属性的基础：hMT+ 和 hV4。人类 MT 复合体 (hMT+) 传统上被认为是背侧通路的一部分，尽管其位置更靠横向，并且已知参与运动感知，而 hV4 是腹侧通路的一部分，被认为参与形状和颜色的处理。我们对这两个领域的了解大部分来自于对非人类灵长类动物的研究。在这里，我们的目标是通过使用大脑刺激技术 rTMS 有选择地暂时削弱每个细胞的反应来测试有关它们在人类视觉中的功能的假设。如果对目标大脑区域的刺激导致特定视觉任务的持续损害（或改善），则该大脑区域很可能在功能上受到影响。使用功能磁共振成像定位相关大脑区域后，我们确定每个区域的大脑刺激对特定视觉任务表现的影响。每项任务都旨在测试与运动、形状或颜色感知相关的专门视觉功能。该计划旨在对 hMT+ 和 hV4 区域在视觉中的功能作用进行全面研究，同时确定这些区域之间的功能重叠和相互作用。***该计划解决了有关人脑视觉信息处理模块化的核心问题。由于人们对 hV4 在人脑中的作用知之甚少，因此该提案具有很高的影响力。这一领域很少使用 rTMS 进行研究，但该方法为理解其在人类视觉中的作用提供了重要的机会。此外，这些实验专门解决了两个关键区域之间的功能重叠问题，目的是了解背侧和腹侧通路的共同功能，而不是简单地了解视觉区域如何作为单独的模块运作。***该项目代表了一个新的研究方向，而不是我之前支持的 NSERC 项目的简单延续。 TMS 方法将我过去十年在实验室中从心理物理学和功能磁共振成像实验中开发出来的对颜色、形状和运动处理的理解结合到一个研究计划中，直接解决人脑两个关键视觉区域的功能。**