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学研究的主要工具。然而，大脑中每时每刻的信号被理解为基本上是电信号。尽管功能磁共振成像的应用研究已经进行了十多年，但功能磁共振成像中的血管信号与脑电活动之间的确切关系在很大程度上还不清楚。在CEBRA的应用中，我们建议完成我们的同步EEG和fMRI方法的开发，并使其适用于细胞外电位的记录。我们相信，我们已经提出了在存在毫伏磁共振伪影的情况下记录微伏脑电信号的强大解决方案，现在准备进入这项技术的开发阶段，在此期间，我们可以完成适合人类研究应用的仪器的建造。很明显，并行EEG和fMRI的问题与并行细胞外记录和fMRI的问题相似，因为伪影的来源本质上是相同的。事实上，后者的信噪比应该稍好一些。然而，在研究和控制这类录音的安全性方面有一些重大的障碍需要克服，这是这项拨款提案的大部分重点。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，这些实验将对巩固功能磁共振成像解释所基于的基础非常重要。在CEBRA计划有限的预算范围内，该项目将停止使用深度电极进行实际的人体实验-人类工作将限于头皮脑电，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，以开始动物实验，并在不久之后启动人体研究。

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.