Note: Due to unforeseen circumstances, this talk has been postponed until Fall 2023
Multi-modal imaging of the brain's physiological dynamics across wake and sleep
Functional magnetic resonance imaging (fMRI) signals driven by systemic physiological changes, such as those associated with heart rate and respiratory variations, are commonly viewed as nuisance components and removed from the fMRI time series in the pre-processing step of most studies. While on the one hand, these physiologically-relevant fluctuations can obscure the neuronal specificity of fMRI and confound the interpretations of resting-state brain functional activity; on the other hand, they may provide meaningful characterizations of the blood flow regulation and vascular anatomy, holding great potential in serving as clinical biomarkers that are complementary to neuronal networks. In this talk, I offer a detailed evaluation of these physiological dynamics across wake and sleep. I will first show that fMRI fluctuations coupled to systemic physiological processes are spatially heterogeneous and that they alone can produce networks that mimic widely-reported resting-state neuronal networks. I will then show how these physiological patterns alter in healthy aging, shedding insights into age-dependent changes in vascular physiology. Finally, I will present our latest work that integrates fMRI with simultaneous EEG and PET to elucidate the physiological and neuronal correlates of fMRI-derived brain functional dynamics across wake and sleep.
Bio:
Dr. Chen is an Instructor and incoming Assistant Professor at the Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH) and Harvard Medical School. Dr. Chen received her PhD from Stanford University, with a major in Electrical Engineering and a minor in Statistics. Her lab advances computational approaches and neuroimaging techniques to probe various neuronal, vascular, energetic and neuromodulatory mechanisms underlying brain functional dynamics.