Functional MRI of Congnitive Processes

描述（由申请人提供）：本申请中提出的研究的总体目标是确定人类额叶和顶叶在执行特定空间认知任务时的大脑激活模式，如高场强（4特斯拉）功能性磁共振成像（fMRI）所揭示的那样。将对健康的女性和男性进行研究。这些任务的设计是为了测试一些更高层次的空间认知过程是如何在额顶叶皮层中表现出来的假设。所提出的研究以路线追踪为中心。这一功能在很大程度上取决于该皮层的完整性，这一点可以从皮层损伤（如中风后）后的紊乱中得到证明。路线跟踪所涉及的过程包括路线段的跟踪以及从一个路段转向下一个路段。我们将测试关于这些过程的神经表征及其顶叶皮层可能起作用的具体方面的五个假设。第一个假设是直线路线段的追踪方向用有序的方式表示，这样就有了一个有序的追踪方向图。第二个假设是，追踪一个复杂的路径（即由多个片段组成的路径）是一个空间分布的过程，随着时间的推移，这个过程顺序地涉及到额顶叶皮层的不同部分。第三个假设是，从一个脑段转到下一个脑段涉及到这两个脑段之间的心理旋转过程，因此激活的强度取决于旋转的角度。第四个假设是，激活对方向变化角度的依赖将在定性和定量上类似于在独立的心理旋转范式中观察到的依赖。最后，第五个假设涉及到女性和男性在追踪复杂序列的大脑激活模式方面的差异，以及对旋转角度和心理旋转的激活依赖。由于功能磁共振成像在高磁场下提供足够的分辨率，甚至对单个受试者来说，这些目标的潜在实现是触手可及的。所获得的数据将使用传统和专门的空间统计技术进行分析。预期获得的结果将为大脑如何处理动态，认知，视觉运动过程提供新的见解，这些过程通常在患有皮质损伤的患者中受到干扰，例如中风后。此外，它们将提供对女性和男性之间可能的半球不对称和差异的见解，特别是在顺序运动和心理旋转任务的表现方面

DESCRIPTION (provided by applicant): The overall goal of the research proposed in this application is to determine the brain activation patterns in the human frontal and parietal lobes during performance of specific spatial cognitive tasks, as revealed by high field strength (4 Tesla) functional magnetic resonance imaging (fMRI). Healthy women and men will be studied. The tasks are designed to test hypotheses of how some higher order spatial cognitive processes are represented in the frontoparietal cortex. The research proposed is centered on route-tracing. This function crucially depends on the integrity of this cortex, as evidenced by its disturbance following cortical damage, e.g. after stroke. The processes involved in route-tracing comprise tracing of route segments as well as turning from one segment to the next. We will test five hypotheses concerning the neural representation of these processes and their specific aspects for which parietal cortex might be instrumental. The first hypothesis is that the direction of tracing of a straight route segment is represented in an orderly fashion, such that there is an orderly map of the direction of tracing. The second hypothesis is that tracing of a complex route (i.e. a route composed of multiple segments) is a spatially distributed process that sequentially engages distinct parts of the frontoparietal cortex, as the process unfolds in time. The third hypothesis is that turning from one segment to the next involves a process of mental rotation between these two segments, such that the intensity of activation will depend on the angle of rotation. The fourth hypothesis is that this dependence of the activation on the angle of directional change will be qualitatively and quantitatively similar to the dependence observed in a stand-alone mental rotation paradigm. Finally, the fifth hypothesis concerns differences between women and men with respect to the brain activation patterns associated with tracing complex sequences and the dependence of activation on the turning angle and mental rotation. The potential achievement of these objectives is within reach, due to the adequate resolution afforded by the fMRI at high magnetic field, even for individual subjects. The data acquired will be analyzed using both traditional as well as specialized spatial statistical techniques. The results to be obtained are expected to provide novel insights into how the brain deals with dynamic, cognitive, visuomotor processes that are commonly disturbed in patients suffering from cortical damage, e.g. after stroke. In addition, they will provide an insight into possible hemispheric asymmetries and differences between women and men, especially with respect to the performance of sequential movement and mental rotation tasks