Simultaneous Electrophysiology and functional MRI

功能磁共振成像（fMRI）已成为人类认知和行为生理研究的主要工具。然而，大脑中即时的信号基本上是电的。尽管已有十多年的应用功能磁共振成像研究，但功能磁共振成像中血管信号与大脑电活动的确切关系在很大程度上是未知的。在这个CEBRA应用程序中，我们建议完成我们的同时脑电图和功能磁共振成像方法的发展，并使这些方法适应于细胞外电位的记录。我们相信，我们已经提出了强大的解决方案，可以在毫伏核磁共振产生的伪像存在的情况下记录微伏脑电图信号，现在准备进入该技术的开发阶段，在此期间我们可以完成适合人类研究应用的设备的构建。很明显，并发EEG和fMRI的问题与并发细胞外记录和fMRI的问题相似，伪影的来源本质上是相同的。事实上，后者的信噪比应该更好一些。然而，在研究和控制这些录音的安全性方面，仍有重大障碍需要克服，这是本拨款提案的重点。我们相信这是一个非常重要的项目，因为这些工具将使我们能够进行关键的验证实验，这对于巩固功能性MRI解释的基础非常重要。在CEBRA项目有限的预算范围内，该项目将停止对深度电极的实际人体实验——人类的工作将仅限于头皮脑电图，以保持在第一阶段机制的有限范围内。项目成功完成后，将立即申请第二阶段资助，展开动物实验，并在其后不久展开人体研究。

Functional MRI (fMRI) has become a dominant tool in the physiological studies of human cognition and behavior. The moment- to-moment signaling within the brain, however, is understood to be fundamentally electrical. Despite over a decade of applied fMRI research the precise relationship the vascular signals in fMRI and the electrical activity of the brain is largely unknown. In this CEBRA application, we propose to complete development of our methods of simultaneous EEG and fMRI and to adapt these to the recording of extracellular potentials. We believe that we have come up with robust solutions for recording microVolt EEG signals in the presence of milliVolt MR-generated artifacts and are now prepared to enter a development phase for this technology during which we can complete the construction of apparatus appropriate for human research applications. It has long been clear that the problems of concurrent EEG and fMRI are similar to those in concurrent extracellular recording and fMRIas the sources of artifacts are essentially the same. In fact, the signal to noise ratio for the latter should be somewhat better. There are however, significant hurdles to overcome in studying and controlling the safety of such recordings, which are the focus of much of this grant proposal. We believe that this is an exceptionally significant project, in that these tools will enable us to perform crucial validation experiments that will be important in firming the very foundations on which the interpretation of functional MRI is based. Within the limited confines of the budget for the CEBRA program, the project will stop short of actual human experimentation with depth electrodes - the human work will be limited to scalp EEG to stay within the limited scope of the stage I mechanism. On its successful completion, the project will be followed immediately by an application for Stage II support to begin animal experimentation and shortly thereafter to initiate human studies.