Neural-Electromagnetic-Hemodynamic Links in Humans

描述（由申请人提供）： 通过将功能性磁共振成像（fMRI）与磁图和脑电图（M/EEG）相结合，可以非侵入性地对人脑激活的时空动力学进行成像。fMRI定位脑血流动力学改变具有良好的空间精度，但时间分辨率差。相反，M/EEG是群体突触活动的瞬时测量，但由于时空抵消而难以定位。此外，从皮层神经元突触电流和细胞放电到颅外血液动力学和电磁信号的传递函数是未知的。血流动力学和电磁信号相互之间的关系及其与其潜在神经基质的关系的潜在可变性使得有必要在人类行为中探索和定义这些关系。我们建议使用线性阵列的微电极来测量神经元的活动。光学测量将使用皮质点光谱和激光多普勒量化血流动力学。在自发活动、校准状态和各种认知任务期间，将在同一皮质微域内进行同时测量。如果成功，这项研究将以前所未有的量化和确定性水平揭示人类认知过程中血液动力学和电磁测量之间的关系以及神经元群体的潜在活动。

DESCRIPTION (provided by applicant): The spatiotemporal dynamics of human brain activation can be non-invasively imaged by combining functional Magnetic Resonance Imaging (fMRI) with magneto- and electro-encephalography (M/EEG). fMRI locates altered cerebral hemodynamics with good spatial accuracy but poor temporal resolution. Conversely, M/EEG are instantaneous measures of population synaptic activity, but are hard to localize because of spatiotemporal cancellation. Furthermore, the transfer functions from cortical neuronal synaptic currents and cell-firing, to extracranial hemodynamic and electromagnetic signals, are unknown. The potential variability of the relationships of hemodynamic and electromagnetic signals to each other, and to their underlying neural substrates, make it necessary to explore and define these relations in behaving humans. We propose to measure neuronal activity using linear arrays of micro-electrodes. Optical measurements will quantify hemodynamics using cortical point spectroscopy and laser Doppler. Simultaneous measures within the same cortical micro-domain will be made during spontaneous activity, calibration states, and a variety of cognitive tasks. If successful, this research will reveal, at an unprecedented level of quantification and certainty, the relations between hemodynamic and electromagnetic measures, and the underlying activity of neuronal populations, during cognition in humans.