Multiscale and wavelet based signal processing for electrophysiological and optical brain imaging

医学成像，特别是功能性神经成像，是生物医学中最具活力的科学和技术领域之一。在头部头皮上获得的生物电测量对于应对神经系统疾病的挑战以及设计能够解码神经活动的技术，例如残疾人控制系统至关重要。电生理学是一门研究生物体电特性的学科，自从理查德·卡顿（Richard Caton，1875年）第一次测量电位以来，它已经有了很大的发展，因此也发明了一些非常有用的测量神经活动的工具。在过去的三十年里，这些技术之一，脑磁图（测量神经活动产生的磁场），已经与另一种工具，脑电图相结合，以提供大脑活动的“生物电磁签名”。第三种技术基于灌注脑组织对红外光的扩散和吸收，使得测量神经活动引起的血液动力学变化成为可能。这种测量对于在临床环境中评估病理是必不可少的，例如癫痫，或者在神经科学和认知科学中，其中在特定情况下研究大脑功能，例如在睡眠期间或当大脑参与涉及感知或记忆的任务时。该研究计划的重点是数字化工具，使其有可能在计算机上处理光学和生物电磁测量，以可视化参与复杂和动态网络，构成大脑活动的皮层区域。我们还将研究颅内电生理测量记录在手术的框架内评估癫痫患者，通过研究发生的快速振荡的爆发，似乎，其中一些至少与病理学有关。从头部表面频谱复杂性的角度来表征这些信号是这项研究计划的挑战之一，该研究计划旨在开发分析“工作人脑”的新方法。

Medical imaging, and functional neuroimaging in particular, is one of the most dynamic of the scientific and technological fields in biomedical. Bioelectrical measurements acquired on the scalp of the head are vitally important in terms of responding to the challenges of neurological illness, as well as for designing technologies capable of decoding neural activity, control systems for the disabled, for example. Electrophysiology, the study of the electrical properties of biological organisms, has developed considerably since the first measurements of electrical potential were recorded by Richard Caton (1875), and some very useful tools for measuring neural activity have been devised as a result. Over the last thirty years, one of these technologies, magnetoencephalography (measurement of the magnetic field created by neural activity), has been combined with another tool, electroencephalography, to provide the 'bioelectromagmetic signature' of the activity of the brain. A third technology, based on the diffusion and absorption of infrared light by perfused brain tissues, makes it possible to measure the hemodynamic variations caused by neural activity. Such measurements are essential in evaluating a pathology in a clinical setting, like epilepsy, for example, or in the neurosciences and cognitive sciences, in which the brain functions are studied in particular situations, like during sleep or when the brain is engaged in tasks involving perception or memory, for example. This research program focuses on the digital tools that make it possible to process optical and bioelectomagnetic measurements on a computer, in order to visualize the regions of the cortex involved in the complex and dynamic networks that constitute brain activity. We will also study the intracranial electrophysiological measurements recorded in epileptic patients evaluated within the framework of a surgery, by studying the bursts of rapid oscillations that occur, and seem, some of them at least, to be related to the pathology. To characterize these signals from the point of view of their spectral complexity at the head surface is one of the challenges of this research program, which is aimed at developing new methods of analyzing the 'working human brain'.