Functional MRI of Congnitive Processes

描述(申请人提供)：本申请中提出的研究的总体目标是确定高场强(4特斯拉)功能磁共振成像(FMRI)显示的特定空间认知任务执行期间人类额叶和顶叶的大脑激活模式。健康的女性和男性将被研究。这些任务的目的是测试一些更高级别的空间认知过程如何在额顶皮质表现的假设。所提出的研究主要集中在路径跟踪上。这一功能关键依赖于大脑皮层的完整性，在大脑皮层损伤后，例如中风后，大脑皮层的紊乱就证明了这一点。路线跟踪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可能有助于顶叶皮质的特定方面的五个假说。第一个假设是直线段的跟踪方向以有序的方式表示，使得存在跟踪方向的有序地图。第二个假设是，对一条复杂路线(即由多个片段组成的路线)的追踪是一个空间分布的过程，随着这个过程在时间上的展开，该过程顺序地涉及额顶皮质的不同部分。第三个假设是，从一个片段转到下一个片段涉及到这两个片段之间的心理旋转过程，因此激活的强度将取决于旋转的角度。第四个假设是，这种激活对方向变化角度的依赖在质和量上都类似于独立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相关的大脑激活模式以及激活对转向角度和心理旋转的依赖方面的差异。这些目标的潜在实现是触手可及的，因为高磁场下的功能磁共振成像提供了足够的分辨率，即使对单个受试者也是如此。将使用传统的和专门的空间统计技术对所获得的数据进行分析。预计将获得的结果将为大脑如何处理动态的、认知的、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，他们还将深入了解男女之间可能存在的半球不对称和差异，特别是在顺序运动和心理旋转任务的执行方面

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