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

其目的是研究人脑对颜色、形状和运动知觉的视觉属性的模块化。尽管视觉图像的这些基本方面在感知上看起来是完整的，但积累的证据表明，它们是在大脑不同的专门区域中单独处理的。大脑的两个关键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，尽管它位于更外侧的位置，并已知参与运动感知，而hV4是腹侧通路的一部分，被认为参与形状和颜色的加工。我们对这两个领域的了解大部分是从对非人类灵长类动物的研究中获得的。在这里，我们的目标是通过使用大脑刺激技术rTMS选择性地和暂时地损害每一个人的反应，来测试关于它们在人类视觉中的功能的假说。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)，很可能是大脑区域在功能上受到了影响。在使用功能磁共振成像定位相关脑区后，我们确定了每个区域的脑刺激对特定视觉任务执行的影响。每项任务都被设计用来测试与运动、形状或颜色感知相关的特殊视觉功能。该计划旨在全面研究hmt+和hV4区在视觉中的功能作用，并确定这两个区之间的功能重叠和相互作用。*该计划解决了关于人脑处理视觉信息的模块化的核心问题。这项提议影响很大，因为人们对hV4在人脑中的作用知之甚少。这一领域很少用rTMS进行研究，但这种方法为理解它在人类视觉中的作用打开了重要的机会。此外，这些实验特别研究了两个关键区域之间的功能重叠，目的是了解背侧和腹侧通路的共同功能，而不是简单地将视觉区域作为单独的模块操作。*这个程序代表了一个新的研究方向，而不是我之前支持的NSERC程序的简单延续。TMS方法将我在过去十年中从心理物理和功能磁共振实验中发展起来的对颜色、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。

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.**