Motion-Tolerant, High-Precision Dynamic Functional Brain Mapping in Infants and Young Children - Project Summary/Abstract Performance of even the most basic perceptual or cognitive task requires the coordination of neural activity across many spatially distinct regions of the human brain. Identifying the code by which these regions communicate, the emergence of functional specialization in each region, and the developmental trajectory of these regions and communication pathways is of critical importance for advancing human neuroscience. Numerous studies over the past 20 years have shown that the structural and functional characteristics of the brain undergo remarkable changes during late childhood and adolescence, which are vital for cognitive, social, and emotional development. Unfortunately, work focused on younger children has lagged far behind, despite data showing massive changes in the first few months of life that are unparalleled in comparison to those observed during later childhood. This lack of work focusing on the early years largely reflects the incredible challenges that exist in imaging infants and young children, with technological limitations being at the forefront. However, an emerging technique called optically pumped magnetometry (OPM) has the capacity to overcome many of these barriers, as it can be fitted to any head size and allow participants to move relatively freely during recordings, making the system ideal for developmental populations and naturalistic experiments (e.g., walking). While early OPM sensors were bulky and too heavy for most pediatric applications, the technology has now advanced to the point where highly sensitive OPMs about the size of a small Lego can be fabricated. If such “Legos” are configured into a high-density array, the spatial precision can eclipse 3 mm while maintaining millisecond temporal resolution. Unfortunately, to date, most OPM studies have been the proof-of-concept type and conducted in adults and older children, with the goal of demonstrating magnetoencephalography (MEG) like measurements at room temperature. In line with the goals of the BRAIN Initiative’s BBQS program (RFA-MH-26-100), we will develop and significantly advance this novel, noninvasive neurophysiological imaging device by alleviating the key barriers that prevent OPM from becoming the mainstay of functional neuroimaging in infants and young children. To this end, we will leverage the highest- density OPM system in North America, the most advanced magnetically shielded room available, high-precision in-house 3D printing, and over 50 years of MEG experience to design a new generation of lightweight, adjustable OPM “helmets” that enable high-density recordings in infants, and integrate this data stream with advanced, real- time monitoring of ambient environmental fields, participant motion, and behavior during the R61 phase. The geometry of these helmets will align to the head surface to enable the sensors to sit flush to the skin to maximize the precision of the OPM source reconstruction. Upon completion of our R61 milestones, we will leverage the new system during the R33 phase to densely map the longitudinal trajectory of the neural dynamics serving visual and social processing during the first year of life, and utilize the new extreme motion tolerance of OPM, developed during the R61 phase, to map the development of motor control in ambulating young children.
