Functional near-infrared imaging using the phase of hemodynamic oscillations

描述（由申请人提供）：该项目探索了利用近红外光谱进行大脑功能研究的新方法的潜力。我们假设脑氧合血红蛋白和脱氧血红蛋白浓度振荡之间的相位关系提供了以下信息：（1）与脑激活相关的血流动力学和氧合相关过程的相互作用，以及（2）涉及不同皮质区域的功能连接网络。具体来说，在这个项目中，我们将使用一种新的基于相量的分析和血流动力学振荡的表示法，对以前在整晚睡眠研究中收集的数据进行新的分析。这种新的分析将使我们能够测试的假设，即与不同的睡眠阶段相关的血液动力学条件诱导氧合血红蛋白和脱氧血红蛋白浓度的自发振荡之间的不同的相位关系在0.1 Hz左右的频率（迈耶波）。我们还将测试氧合血红蛋白和脱氧血红蛋白浓度变化具有不同的相对相位的假设，这取决于激活的皮层区域和/或刺激方案。最后，我们将进行试点测量，以测试这种新的基于相位的方法在研究大脑功能连接网络中的潜力。该项目可能会导致一种新的方法来功能性大脑研究，并探讨信号是无法访问的功能性磁共振成像，涉及顺磁性和反磁性血红蛋白物种。

DESCRIPTION (provided by applicant): This project explores the potential of a novel approach to functional studies of the brain with near-infrared spectroscopy. We hypothesize that the phase relationship between oscillations of cerebral oxy-hemoglobin and deoxy-hemoglobin concentrations provide information about (1) the interplay of hemodynamic and oxygenation-related processes that are associated with brain activation, and (2) functional connectivity networks involving distinct cortical areas. Specifically, in this project we will perform a new analysis of data collected previously in a full-night sleep study using a novel phasor-based analysis and representation of hemodynamic oscillations. This new analysis will allow us to test the hypothesis that hemodynamic conditions associated with different sleep stages induce different phase relationship between spontaneous oscillations of oxy-hemoglobin and deoxy-hemoglobin concentrations at frequencies around 0.1 Hz (Mayer waves). We will also test the hypothesis that oxy-hemoglobin and deoxy-hemoglobin concentration changes have different relative phases depending on the cortical area activated and/or the stimulation protocol. Finally, we will perform pilot measurements to test the potential of this new phase-based method in studying functional connectivity networks in the brain. This project can lead to a novel approach to functional brain studies, and explores signals that are not accessible with functional magnetic resonance imaging, involving both paramagnetic and diamagnetic hemoglobin species.