NEURAL MECHANISMS OF TACTILE SPATIO-TEMPORAL INTEGRATION

这项建议描述了在人类和猴子身上进行的一系列实验，这些实验研究了触觉时空有序刺激的神经整合。拟议研究的一个基本目标是在皮质区域的激活水平上理解这种神经处理，并在这些区域内的特定模式神经元活动的水平上理解这种神经处理。为了实现这一目标，将使用功能磁共振成像(FMRI)绘制人类体感皮质的图谱，并使用多电极记录来记录猴子体感皮质的神经反应模式。这个项目有三个具体目标。首先，定义触觉运动刺激激活的人类大脑皮层区域。在3特斯拉fMRI扫描仪中使用事件相关设计将允许将映射作为个人行为反应的函数。第二，检测猴/中央后回(PoCG)和较高皮质区域触觉运动刺激的快速神经整合。多电极记录技术将记录在触觉表观运动刺激呈现时，大脑皮层超过毫米处的动作电位激发模式。这将允许分析分布式编码方案和组织单独的触觉感受野。第三，检查在时空有序的刺激中，没有唤起运动知觉的大脑皮层的激活。使用功能磁共振成像和多电极技术，我们将研究由一系列刺激引起的皮质激活，从明显的运动刺激到感知稳定的刺激。通过映射这些激活模式，我们将深入了解支持运动感知的神经编码的出现，以及支持各种时空知觉交互的神经机制。这些研究将扩大我们对快速时空触觉整合的理解，这是成功的触觉假体设计中的一个重要课题。此外，他们将提供人类和猴子的神经处理过程的直接比较，这种比较将扩大我们对人类功能与最重要的临床和科学模型系统--非人类灵长类之间的联系的了解。

This proposal describes a series of experiments in humans and monkeys that investigate neural integration of tactile spatio- temporally ordered stimuli. A fundamental goal of the proposed research is to understand this neural processing at the level of activation of cortical areas, and at the level of specific patterns neuronal activity within those areas. To achieve this goal, functional magnetic resonance imaging (fMRI) will be used to map the human somatosensory cortex, and multi-electrode recording will be used to record neural response patterns in the monkey somatosensory cortex. This project has three specific aims. First, to define human cortical areas activated by tactile motion stimuli. Use of an event-related design in a 3 Tesla fMRI scanner will permit mapping as a function of individual behavioral responses. Second, to examine rapid neural integration of tactile motion stimuli in the monkey/postcentral gyrus (PoCG) and a higher cortical area. Multi-electrode recording techniques will record patterns of action potential firing from over millimeters of the cortex during the presentation of tactile apparent motion stimuli. This will permit the analysis of distributed coding schemes and the organization of individual tactile receptive fields. Third, to examine cortical activation during spatio-temporally ordered stimuli that do not evoke the percept of motion. Using fMRI and multi-electrode techniques, we will examine cortical activation evoked by a continuum of stimuli, ranging from apparent motion stimuli to perceptually stable stimuli. By mapping these activation patterns, we will gain insight into both the emergence of neural coding supporting motion perception, and into the neural mechanisms, that support a variety of spatio-temporal perceptual interactions. These studies will expand our understanding of rapid spatio-temporal tactile integration, an important topic in the design of successful tactile prosthetics. Further, they will provide direct comparisons between the neural processing in humans and monkeys, a comparison that will expand our knowledge of the connections between human function and the most important clinical and scientific model system, the non-human primate.