Wearable magnetoencephalography (MEG): The next-generation of dynamic human neuroimaging

项目总结/文摘

Project Summary/Abstract The Omaha magnetoencephalography (MEG) site is home to one of the most productive, internationally-known MEG groups in the world. In 2020 alone, they published over 30 peer-reviewed MEG-centric publications, had numerous major NIH awards, and made high impact discoveries spanning multiple areas of human neuroscience. MEG is an advanced method for noninvasively imaging population-level neurophysiological activity with high temporal (< 1 ms) and spatial precision (2-3 mm). Application of the method has expanded substantially over the past decade due to technical advancements and the growing interest in neural oscillations, dynamic connectivity, and other metrics where spatiotemporal precision is extremely important. The Omaha MEG group has had a major role in this growth and continues to lead the way in many areas of MEG research, often exceeding all other MEG sites on major measures of scientific productivity and impact. However, this group is now at a crossroads where their future growth, and even existence, is threatened by a revolutionary paradigm shift in the field of neurophysiological imaging, and a worldwide helium shortage. Briefly, conventional MEG systems are large and stationary, requiring research participants to sit as still as possible for extended periods of time while undergoing recordings. This creates major challenges for acquiring data in specific patient populations and young children. Further, the dimensions of the sensor array are fixed within the MEG helmet, which is designed to accommodate 98% of adults. This translates into large gaps between the scalp surface and the sensor array in young children and huge gaps in infants. Since the strength of magnetic fields fall off exponentially with increasing distance from the current source (i.e., active neural populations), the net impact of this is strongly attenuated neural responses in children and infants and thus poor precision. Additionally, conventional MEG requires liquid helium to support superconducting temperatures, which is not only very expensive but also increasingly difficult to obtain in the current era of helium shortages. Given these concerns, we are proposing to purchase a state-of-the-art optically- pumped magnetometry (OPM) system. The idea of OPM has been around for decades, but major breakthroughs through President Obama’s BRAIN Initiative have moved the technology from a physics experiment to cutting edge applications in neuroscience. OPM is the future of MEG, as it overcomes the key limitations of conventional systems and in most cases offers superior precision. Specifically, OPM: (1) does not require liquid helium and thus sensors can be placed directly on the scalp for optimal sensitivity, (2) can be fitted to any head size, including pediatric and infant populations, and (3) allows participants to move relatively freely during recordings, making the system ideal for developmental and clinical populations, as well as naturalistic experiments (e.g., walking). Thus, OPM is a significant, major step forward and will give rise to a whole new era of functional imaging. With this technology, the Omaha MEG group will remain at the forefront of discovery in several major topic areas that are described in the proposal and of clear interest to the NIH and the translational neuroscience community.